TWI731165B - Sensitizing dye, sensitizing dye for photoelectric conversion, photoelectric conversion element using the same, and dye-sensitized solar cell - Google Patents

Abstract

[式中，R¹ ～R⁶ 可相同亦可不同，分別獨立地表示氫原子、鹵素原子、特定之烷基、或特定之烷氧基， R⁷ 及R⁸ 可相同亦可不同，表示特定之烷基、特定之環烷基、特定之烯基、特定之芳烷基、或特定之芳基，R⁷ 與R⁸ 亦可相互鍵結而形成環。 X表示1價基。]The present invention provides a sensitizing dye represented by the following general formula (1). [化1]

[In the formula, R ¹ to R ⁶ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, a specific alkyl group, or a specific alkoxy group. R ⁷ and R ⁸ may be the same or different, and represent specific The alkyl group, the specific cycloalkyl group, the specific alkenyl group, the specific aralkyl group, or the specific aryl group, R ⁷ and R ⁸ may also be bonded to each other to form a ring. X represents a monovalent group. ]

Description

Sensitizing dye, sensitizing dye for photoelectric conversion, photoelectric conversion element using the same, and dye-sensitized solar cell

The present invention relates to a sensitizing dye used in a dye-sensitized photoelectric conversion element, a photoelectric conversion element using the sensitizing dye, and a dye-sensitized solar cell.

系色素等(例如，參照專利文獻1、2)。近年來，作為增感色素，報告有具有苯并吡喃構造、萘二甲醯亞胺構造、茀構造、茀酮構造、二苯并噻吩構造之化合物(例如，參照專利文獻3～7)。 又，作為吸附於氧化鈦等半導體粒子表面且用以將增感色素所產生之激發電子高效地搬運至半導體之電子吸引部，亦提出有具有二氫茚酮構造之化合物(例如，參照專利文獻8～10)。然而，該等有機色素雖然具有經濟且吸光係數較大且可利用構造之多樣性進行吸收特性之控制等優點，但目前未獲得於光電轉換效率及經時穩定性之方面充分地満足所要求之特性者。 [先前技術文獻] [專利文獻] [專利文獻1]日本專利特開平11-214730號公報 [專利文獻2]日本專利特開平11-238905號公報 [專利文獻3]日本專利特開2003-17146號公報 [專利文獻4]日本專利特開2004-227825號公報 [專利文獻5]日本專利特開2009-266633號公報 [專利文獻6]日本專利特開2009-277527號公報 [專利文獻7]日本專利特開2015-191934號公報 [專利文獻8]日本專利特開2011-207784號公報 [專利文獻9]日本專利特開2012-51854號公報 [專利文獻10]日本專利特開2016-6811號公報 [非專利文獻] [非專利文獻1]「Nature」，(英國)，1991年，第353卷，p.737-740In recent years, carbon dioxide produced by fossil fuels such as coal, oil, and natural gas, as a greenhouse gas, is causing global warming or environmental damage due to global warming. Due to the increase in global energy consumption associated with the increase in population, there is a growing concern that environmental damage on a global scale is growing. Under such circumstances, the industry is actively studying the use of renewable energy, which is different from fossil fuels and is less likely to be depleted. Instead of thermal power or atomic power that consumes fossil fuels, as a power generation method that utilizes the next generation of renewable energy that can contribute to the prevention of global warming, the use of solar energy, centered on solar power generation, is becoming more and more important. From the power generation and charging of watches or portable small electronic devices to the small-scale power generation facilities in houses, buildings or fallow land that can save solar and heat costs, development or application in various fields is underway. As a method of solar power generation, photoelectric conversion elements that convert solar energy into electrical energy are used in solar cells. As a solar cell, it mainly researches inorganic solar cells such as single crystal, polycrystalline, amorphous silicon, gallium arsenide, cadmium sulfide, indium copper selenide and other compound semiconductor systems. At present, it is widely used in residential or small-scale power generation facilities. Practical. However, these inorganic solar cells have problems such as higher manufacturing costs or difficulty in securing raw materials. On the other hand, organic solar cells such as organic thin-film solar cells or dye-sensitized solar cells using various organic materials have also been developed, although the photoelectric conversion efficiency or durability is significantly lower than that of inorganic solar cells. Organic solar cells are more advantageous than inorganic solar cells in terms of manufacturing cost, larger area, lighter weight, thinner film, light transmittance, wider range of absorption wavelength, flexibility, and material assurance. Among them, the dye-sensitized solar cell proposed by Graetzel et al. (refer to Non-Patent Document 1) includes a thin film electrode containing porous titanium oxide as a semiconductor, a ruthenium complex dye adsorbed on the surface of the semiconductor in order to expand the photosensitive wavelength range, Wet solar cells containing iodine-containing electrolyte are expected to have higher photoelectric conversion efficiency than amorphous silicon solar cells. In addition, the dye-sensitized solar cell has a simple element structure compared with other solar cells and can be manufactured without large-scale manufacturing equipment, and therefore, it is attracting attention as a next-generation solar cell. As a sensitizing dye used in dye-sensitized solar cells, ruthenium complexes are considered the most advantageous in terms of photoelectric conversion efficiency. However, since ruthenium is a precious metal, it is disadvantageous in terms of manufacturing cost, and when a large amount of ruthenium complexes are required for practical use, resource constraints also become a problem. Therefore, researches on dye-sensitized solar cells using organic dyes that do not contain noble metals such as ruthenium as sensitizing dyes are currently underway. As organic pigments that do not contain precious metals, there are reports of coumarin pigments, cyanine pigments, merocyanine pigments, rhodanine pigments, phthalocyanine pigments, porphyrin pigments, 𠮿

Dyes, etc. (for example, refer to Patent Documents 1 and 2). In recent years, as sensitizing dyes, compounds having a benzopyran structure, a naphthalimide structure, a stilbene structure, a stellone structure, and a dibenzothiophene structure have been reported (for example, refer to Patent Documents 3 to 7). In addition, as an electron attracting part that is adsorbed on the surface of semiconductor particles such as titanium oxide and used to efficiently transport the excited electrons generated by the sensitizing dye to the semiconductor, a compound having an indanone structure has also been proposed (for example, refer to Patent Literature 8～10). However, although these organic pigments have the advantages of being economical, having a large absorption coefficient, and being able to control the absorption characteristics by using the diversity of the structure, they have not yet achieved sufficient requirements in terms of photoelectric conversion efficiency and stability over time. Characteristic. [Prior Art Document] [Patent Document] [Patent Document 1] Japanese Patent Laid-Open No. 11-214730 [Patent Document 2] Japanese Patent Laid-Open No. 11-238905 [Patent Document 3] Japanese Patent Laid-Open No. 2003-17146 Publication [Patent Document 4] Japanese Patent Laid-Open No. 2004-227825 [Patent Document 5] Japanese Patent Laid-Open No. 2009-266633 [Patent Document 6] Japanese Patent Laid-Open No. 2009-277527 [Patent Document 7] Japanese Patent Japanese Patent Laid-Open No. 2015-191934 [Patent Document 8] Japanese Patent Laid-Open No. 2011-207784 [Patent Document 9] Japanese Patent Laid-Open No. 2012-51854 [Patent Document 10] Japanese Patent Laid-Open No. 2016-6811 [Patent Document 10] Non-Patent Document] [Non-Patent Document 1] "Nature", (UK), 1991, Vol. 353, p.737-740

[式中，R¹ ～R⁶ 可相同亦可不同，分別獨立地表示氫原子、鹵素原子、碳原子數1～6之直鏈狀或者支鏈狀之烷基、或碳原子數1～6之直鏈狀或者支鏈狀之烷氧基， R⁷ 及R⁸ 可相同亦可不同，表示亦可具有取代基之碳原子數1～20之直鏈狀或者支鏈狀之烷基、亦可具有取代基之碳原子數3～20之環烷基、亦可具有取代基之碳原子數2～20之直鏈狀或者支鏈狀之烯基、亦可具有取代基之碳原子數7～26之芳烷基、或亦可具有取代基之碳原子數6～30之芳基，R⁷ 與R⁸ 亦可相互鍵結而形成環。 X表示一價基]。 2.一種增感色素，其中於上述通式(1)中，X為下述通式(X1)、(X2)或(X3)所表示之一價基。 [化2]

[式中，R⁹ 表示酸性基] [化3]

[式中，L及M可相同亦可不同，表示具有1個或2個酸性基作為取代基之碳原子數1～6之直鏈狀或者支鏈狀之烷基、或未經取代之碳原子數1～6之直鏈狀或者支鏈狀之烷基。其中，至少L或M之任一者為具有1個或2個酸性基作為取代基之碳原子數1～6之直鏈狀或者支鏈狀之烷基。p表示0～2之整數，於p為2之情形時，複數個存在之L可彼此相同亦可不同]。 [化4]

[式中，R¹¹ 及R¹² 表示氫原子或酸性基，至少R¹¹ 或R¹² 之任一者為酸性基。 R¹³ 及R¹⁴ 可相同亦可不同，表示氫原子、 亦可具有取代基之碳原子數1～18之直鏈狀或者支鏈狀之烷基、 亦可具有取代基之碳原子數1～18之直鏈狀或者支鏈狀之烷氧基、 或亦可具有取代基之碳原子數2～18之直鏈狀或者支鏈狀之烯基， R¹³ 與R¹⁴ 亦可分別相互鍵結而形成環。 r表示0～4之整數，於r為2～4之整數之情形時，複數個存在之R¹³ 及R¹⁴ 係其R¹³ 彼此、R¹⁴ 彼此可分別相同亦可不同] 3.一種增感色素，其中於上述通式(1)中，R¹ ～R⁶ 全部為氫原子。 4.如上述3中記載之增感色素，其中於上述通式(1)中，R⁷ 及R⁸ 係亦可具有取代基之碳原子數3～20之環烷基、或亦可具有取代基之碳原子數6～30之芳基之任一者，R⁷ 與R⁸ 亦可相互鍵結而形成環。 5.一種光電轉換用增感色素，其包含上述增感色素。 6.一種光電轉換元件，其使用有上述光電轉換用增感色素。 7.一種色素增感太陽電池，其使用有上述光電轉換元件。 [發明之效果] 根據本發明之增感色素，可獲得可高效地提取電流之光電轉換用增感色素。又，藉由使用該光電轉換用增感色素，而可獲得高效率且高耐久性之光電轉換元件及色素增感太陽電池。[Problem to be solved by the invention] The problem to be solved by the present invention is to provide a sensitizing dye with a novel structure that can expand the photosensitive wavelength range, and further provide a sensitizing dye as a photoelectric conversion enhancement agent that can efficiently extract current. Photoelectric conversion element with good photoelectric conversion and dye-sensitized solar cell used for sensitive pigment. [Technical Means to Solve the Problem] In order to solve the above-mentioned problems, the inventors have conducted diligent studies on the improvement of the photoelectric conversion characteristics of the sensitizing dye, and found that a sensitizing dye with a specific structure is used as a sensitizing dye for photoelectric conversion When used, a photoelectric conversion element with high efficiency and high durability can be obtained. That is, the present invention includes the following contents. 1. A sensitizing dye represented by the following general formula (1). [化1]

[In the formula, R ¹ to R ⁶ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 6 carbon atoms, or a carbon number of 1 to 6 R ⁷ and R ⁸ may be the same or different, and represent a linear or branched alkyl group having 1 to 20 carbon atoms, which may also have a substituent. A cycloalkyl group having 3 to 20 carbon atoms that may have a substituent, a linear or branched alkenyl group having 2 to 20 carbon atoms that may have a substituent, or a substituted carbon number 7 The aralkyl group of -26 or the aryl group of 6 to 30 carbon atoms which may have a substituent, and R ⁷ and R ⁸ may be bonded to each other to form a ring. X represents a univalent base]. 2. A sensitizing dye, wherein in the above general formula (1), X is a monovalent group represented by the following general formula (X1), (X2) or (X3). [化2]

[In the formula, R ⁹ represents an acidic group] [化3]

[In the formula, L and M may be the same or different, and represent a linear or branched alkyl group having 1 to 6 carbon atoms, or an unsubstituted carbon having 1 or 2 acidic groups as substituents A linear or branched alkyl group having 1 to 6 atoms. Among them, at least either L or M is a linear or branched alkyl group having 1 to 6 carbon atoms and having 1 or 2 acidic groups as a substituent. p represents an integer of 0-2, and when p is 2, a plurality of L may be the same or different from each other]. [化4]

[In the formula, R ¹¹ and R ¹² represent a hydrogen atom or an acidic group, and at least one of R ¹¹ or R ¹² is an acidic group. R ¹³ and R ¹⁴ may be the same or different, and represent a hydrogen atom, a linear or branched alkyl group having 1 to 18 carbon atoms which may have a substituent, and a carbon number of 1 to 18 which may have a substituent 18 is a linear or branched alkoxy group, or a linear or branched alkenyl group with 2 to 18 carbon atoms that may have a substituent, R ¹³ and R ¹⁴ may be bonded to each other, respectively And form a ring. r represents an integer of 0 to 4, when r is in the case of an integer of 2 to 4, the presence of a plurality of R ¹³ and R ¹⁴ R ¹³ in which their one another, each R ¹⁴ may be the same or different from each other] A sensitized In the dye, in the above general formula (1), all of R ¹ to R ⁶ are hydrogen atoms. 4. The sensitizing dye as described in 3 above, wherein in the above general formula (1), R ⁷ and R ⁸ may be substituted with a C 3-20 cycloalkyl group, or may be substituted In any of the aryl groups having 6 to 30 carbon atoms, R ⁷ and R ⁸ may be bonded to each other to form a ring. 5. A sensitizing dye for photoelectric conversion, which comprises the above-mentioned sensitizing dye. 6. A photoelectric conversion element using the above-mentioned sensitizing dye for photoelectric conversion. 7. A dye-sensitized solar cell using the photoelectric conversion element described above. [Effects of the invention] According to the sensitizing dye of the present invention, a sensitizing dye for photoelectric conversion that can efficiently extract current can be obtained. In addition, by using the sensitizing dye for photoelectric conversion, a photoelectric conversion element and a dye-sensitized solar cell with high efficiency and high durability can be obtained.

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將通式(1)所表示之本發明之增感色素之具體例示於以下之式(A-1)～(A-51)，但本發明並不限定於該等。以下之例示化合物係表示可能產生之立體異構物中之一例者，認定為包含其他全部立體異構物。又，亦可分別為2種以上之立體異構物之混合物。 [化7]

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通式(1)所表示之本發明之增感色素可使用公知之方法進行合成。於通式(1)中，於R¹ ～R⁶ 全部為氫原子之情形時，可以例如以下方式進行合成。藉由進行下述式(4)所表示之3,7-二溴二苯并噻吩與下述式(5)所表示之胺化合物之Buchwald-Hartwig反應，而可獲得下述式(6)所表示之中間物即單溴化體。進而，將通式(6)之溴基(-Br)按照常規方法或藉由進行與具有相應取代基之硼酸之Suzuki偶合等交叉偶合反應轉換為甲醯基(-CHO)，藉此，可獲得下述通式(7)所表示之中間物即甲醯物。其中，於下述通式(5)～(7)中，R⁷ 、R⁸ 、R¹³ 及R¹⁴ 表示與通式(1)中之符號相同之含義，同樣地，r表示0～4之整數。 下述通式(7)所表示之甲醯物(r＝0)例如可藉由利用N,N-二甲基甲醯胺(DMF)捕捉藉由通式(6)所表示之溴化體與丁基鋰等之金屬鹵素交換而獲得之芳基鋰而進行合成。 下述通式(7)所表示之甲醯物(r＝1～4)之合成可使用例如5-甲醯基-2-噻吩硼酸或5'-甲醯基-2,2'-聯噻吩-5-硼酸等具有含甲醯基及相應取代基之噻吩環之硼酸，藉由進行交叉偶合反應，而合成通式(7)所表示之甲醯物。 [化58]

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本發明之通式(1)中之X為上述通式(X1)、(X2)或(X3)所表示之一價基之增感色素可藉由根據目標之X1～X3進行上述通式(7)之中間物(甲醯物)與分別相應之化合物之縮合反應而進行合成。具體而言，可藉由進行與氰乙酸等(X為上述通式(X1)之情形)、繞丹寧-3-乙酸等繞丹寧化合物(X為上述通式(X2)之情形)、或如下述式(8)所表示之茚酮化合物(X為上述通式(X3)之情形)之縮合反應而進行合成。 [化62]

再者，關於成為起始原料之上述式(4)或(5)等，可使用市售者，亦可使用藉由公知之方法合成者。上述通式(8)所示之茚酮化合物可藉由上述專利文獻8～10中記載之方法而容易地合成。 又，於R¹ ～R⁶ 為氫原子以外之取代基之情形時，可藉由使用分別對應之二溴二苯并噻吩衍生物等進行與上述相同之反應，而合成通式(1)所表示之本發明之增感色素。 作為通式(1)所表示之本發明之增感色素之化合物之精製方法，可列舉：利用管柱層析法進行之精製；利用矽膠、活性碳、活性白土等之吸附精製；利用溶劑之再結晶或晶析法等公知之方法。又，該等化合物之鑑定可藉由核磁共振分析(NMR)等而進行。 本發明之增感色素可單獨地使用，亦可將2種以上併用。又，本發明之增感色素可與不屬於本發明之其他增感色素併用。作為其他增感色素之具體例，可列舉釕錯合物、香豆素色素、花青系色素、部花青系色素、若丹菁系色素、酞菁系色素、卟啉系色素、𠮿

系色素等上述通式(1)所表示之增感色素以外之增感色素。於將本發明之增感色素與該等其他增感色素組合而使用之情形時，較佳為將其他增感色素相對於本發明之增感色素之使用量設為10～200重量%，更佳為設為20～100重量%。 本發明之增感色素可作為鹵化銀、氧化鋅、氧化鈦等各種成像材料用之感光體、光觸媒、光功能性材料等之分光增感色素應用，亦可作為色素增感型之光電轉換元件等所使用之光電轉換用增感色素等應用。又，可利用由本發明之增感色素激發之能量，應用於與其他光電轉換元件組合而製作之有機薄膜太陽電池或鈣鈦礦太陽電池等下一代型太陽電池、下一代蓄電池等之光-能量(電、熱、資訊等)轉換元件。例如，於本發明中，製作色素增感型之光電轉換元件之方法並無特別限定，較佳為於導電性支持體(電極)上形成半導體層，使本發明之光電轉換用增感色素吸附(擔載)於該半導體層而製作光電極之方法(參照圖1)。作為使色素吸附之方法，一般而言係將半導體層長時間浸漬於使色素溶解於溶劑中而獲得之溶液中之方法。於將本發明之光電轉換用增感色素併用2種以上之情形時，或者於將本發明之光電轉換用增感色素與其他增感色素併用之情形時，可製備所使用之全部色素之混合溶液並將半導體層浸漬於其中，又，亦可針對各色素製備各自之溶液，將半導體層依序浸漬於各溶液中。 於本發明中，作為導電性支持體，除金屬板以外，可使用於表面設置有具有導電性材料之導電層之玻璃基板或塑膠基板。作為導電性材料之具體例，可列舉：金、銀、銅、鋁、鉑等金屬、摻氟之氧化錫、銦-錫複合氧化物等導電性透明氧化物半導體、碳等，較佳為使用塗佈有摻氟之氧化錫薄膜之玻璃基板。 於本發明中，作為形成半導體層之半導體之具體例，可列舉：氧化鈦、氧化鋅、氧化錫、氧化銦、氧化鋯、氧化鎢、氧化鉭、氧化鐵、氧化鎵、氧化鎳、氧化釔等金屬氧化物；硫化鈦、硫化鋅、硫化鋯、硫化銅、硫化錫、硫化銦、硫化鎢、硫化鎘、硫化銀等金屬硫化物；硒化鈦、硒化鋯、硒化銦、硒化鎢等金屬硒化物；矽、鍺等單體半導體等。該等半導體不僅可單獨地使用，亦可將2種以上混合而使用。於本發明中，較佳為使用選自氧化鈦、氧化鋅、氧化錫中之1種或2種以上作為半導體。 本發明中之半導體層之態樣並無特別限定，較佳為具有包含微粒子之多孔質構造之薄膜。藉由多孔質構造等，而半導體層之實質之表面積變大，若向半導體層之色素吸附量增大，則可獲得高效率之光電轉換元件。半導體粒徑較佳為5～500 nm，更佳為10～100 nm。半導體層之膜厚通常為2～100 μm，更佳為5～20 μm。作為形成半導體層之方法，可列舉將包含半導體微粒子之膏利用旋轉塗佈法、刮刀法、壓輥法、網版印刷法等濕式塗佈法塗佈於導電性基板上之後，藉由焙燒將溶劑或添加物去除而進行製膜之方法，或藉由濺鍍法、蒸鍍法、電鍍法、電沈積法、微波照射法等進行製膜之方法，但並不限定於該等。 於本發明中，包含半導體微粒子之膏可使用市售品，亦可使用藉由使市售之半導體微粉末分散於溶劑中而製備之膏等。作為製備膏之時所使用之溶劑之具體例，可列舉：水；甲醇、乙醇、異丙醇等醇系溶劑；丙酮、甲基乙基酮、甲基異丁酮等酮系溶劑；正己烷、環己烷、苯、甲苯等烴系溶劑，但並不限定於該等。又，該等溶劑可單獨使用或者以2種以上之混合溶劑之形式使用。 於本發明中，作為使半導體微粉末分散於溶劑中之方法，可利用研缽等進行研碎，亦可使用球磨機、塗料調節器、立式珠磨機、水平型珠磨機、磨碎機等分散機。於製備膏之時，較佳為添加界面活性劑等以防止半導體微粒子之凝聚，較佳為添加聚乙二醇等增黏劑以使其增黏。 本發明之光電轉換用增感色素向半導體層表面上之吸附係藉由將半導體層浸於該色素溶液中並於室溫下放置30分鐘～100小時或者於加熱條件下放置10分鐘～24小時而進行，較佳為於室溫下放置10～20小時。又，該色素溶液中之色素濃度較佳為10～2000 μm，更佳為50～500 μm。 作為使本發明之光電轉換用增感色素吸附於半導體層表面上時所使用之溶劑之具體例，可列舉：甲醇、乙醇、異丙醇、第三丁醇等醇系溶劑；丙酮、甲基乙基酮、甲基異丁酮等酮系溶劑；甲酸乙酯、乙酸乙酯、乙酸正丁酯等酯系溶劑；二乙醚、1,2-二甲氧基乙烷、四氫呋喃、1,3-二氧雜環戊烷等醚系溶劑；N,N-二甲基甲醯胺、N,N-二甲基乙醯胺、N-甲基-2-吡咯烷酮等醯胺系溶劑；乙腈、甲氧基乙腈、丙腈等腈系溶劑；二氯甲烷、氯仿、三溴甲烷、鄰二氯苯等鹵化烴系溶劑；正己烷、環己烷、苯、甲苯等烴系溶劑，但並不限定於該等。該等溶劑可單獨使用或者以2種以上之混合溶劑之形式使用。該等溶劑之中，較佳為使用選自甲醇、乙醇、第三丁醇、丙酮、甲基乙基酮、四氫呋喃、乙腈中之1種或2種以上。 於使本發明之光電轉換用增感色素吸附於半導體層表面上時，亦可使膽酸或去氧膽酸、鵝去氧膽酸、膽石酸、去氫膽酸等膽酸衍生物溶解於色素溶液中而與色素共吸附。藉由使用膽酸或膽酸衍生物而色素彼此之締合被抑制，從而可於光電轉換元件中自色素向半導體層高效地進行電子注入。於使用膽酸或膽酸衍生物之情形時，色素溶液中之其等之濃度較佳為0.1～100 mM，更佳為0.5～10 mM。 作為本發明之光電轉換元件所使用之相對電極(電極)，只要為具有導電性者則並無特別限定，為了促進氧化還原離子之氧化還原反應，較佳為使用具有觸媒功能之導電性材料。作為該導電性材料之具體例，可列舉鉑、銠、釕、碳等，但並不限定於該等。於本發明中，尤佳為將於導電性支持體上形成有鉑之薄膜者作為相對電極使用。又，作為形成導電性薄膜之方法，可列舉將包含導電性材料之膏藉由旋轉塗佈法、刮刀法、壓輥法、網版印刷法等濕式塗佈法塗佈於導電性基板上之後，藉由焙燒將溶劑或添加物去除而進行製膜之方法，或藉由濺鍍法、蒸鍍法、電鍍法、電沈積法、微波照射法等進行製膜之方法，但並不限定於該等。 於本發明之光電轉換元件中，於一對對向之電極間填充電解質，而形成電解質層。作為所使用之電解質，較佳為氧化還原電解質。作為氧化還原電解質，可列舉碘、溴、錫、鐵、鉻、蒽醌等氧化還原離子對，但並不限定於該等。該等之中，較佳為碘系電解質、溴系電解質。於碘系電解質之情形時，可使用例如碘化鉀、碘化鋰、碘化二甲基丙基咪唑鎓等與碘之混合物。於本發明中，較佳為使用使該等電解質溶解於溶劑中而獲得之電解液。電解液中之電解質之濃度較佳為0.05～5 M，更佳為0.2～1 M。 作為使電解質溶解之溶劑，可列舉：乙腈、甲氧基乙腈、丙腈、3-甲氧基丙腈、苯甲腈等腈系溶劑；二乙醚、1,2-二甲氧基乙烷、四氫呋喃等醚系溶劑；N,N-二甲基甲醯胺、N,N-二甲基乙醯胺等醯胺系溶劑；碳酸乙二酯、碳酸丙二酯等碳酸酯系溶劑；γ-丁內酯、γ-戊內酯等內酯系溶劑，但並不限定於該等。該等溶劑可單獨使用或者以2種以上之混合溶劑之形式使用。該等溶劑之中，較佳為腈系溶劑。 於本發明中，為了色素增感型光電轉換元件之開路電壓及填充因數之進一步提昇，亦可使上述電解液中含有胺系化合物。作為胺系化合物，可列舉4-第三丁基吡啶、4-甲基吡啶、2-乙烯基吡啶、N,N-二甲基-4-胺基吡啶、N,N-二甲基苯胺、N-甲基苯并咪唑等。電解液中之胺系化合物之濃度較佳為0.05～5 M，更佳為0.2～1 M。 作為本發明之光電轉換元件中之電解質，亦可使用添加凝膠化劑或聚合物等而獲得之凝膠狀電解質或使用聚環氧乙烷衍生物等聚合物之固體電解質。藉由使用凝膠狀電解質、固體電解質，而可使電解液之揮發減少。 於本發明之光電轉換元件中，亦可於一對對向之電極間形成固體電荷傳輸層來代替電解質。固體電荷傳輸層所包含之電荷傳輸物質較佳為電洞傳輸物質。作為電荷傳輸物質之具體例，可列舉：碘化銅、溴化銅、硫氰化銅等無機電洞傳輸物質、聚吡咯、聚噻吩、聚對苯乙炔、聚乙烯咔唑、聚苯胺、㗁二唑衍生物、三苯胺衍生物、吡唑啉衍生物、茀酮衍生物、腙化合物、茋化合物等有機電洞傳輸物質，但並不限定於該等。較佳為於固體電荷傳輸層含有鋰雙(三氟甲磺醯基)醯亞胺或者鋰二異丙基醯亞胺等鋰化合物、4-第三丁基吡啶或者2-戊基吡啶等鹼性胺化合物等作為添加劑。又，亦可為了導電性提昇，添加用以使有機電洞傳輸物質之一部分成為自由基陽離子之氧化劑。作為氧化劑，可列舉三(2-(1H-吡唑-1-基)-4-第三丁基吡啶)鈷(III)三(雙(三氟甲基磺醯基)醯亞胺)等鈷錯合物等。 於本發明中，於使用有機電洞傳輸物質形成固體電荷傳輸層之情形時，亦可併用膜形成性黏合劑樹脂。作為膜形成性黏合劑樹脂之具體例，可列舉聚苯乙烯樹脂、聚乙烯醇縮醛樹脂、聚碳酸酯樹脂、聚碸樹脂、聚酯樹脂、聚苯醚樹脂、聚芳酯樹脂、醇酸樹脂、丙烯酸系樹脂、苯氧基樹脂等，但並不限定於該等。該等樹脂可單獨使用或者以共聚物之形式將1種或2種以上混合而使用。該等黏合劑樹脂相對於有機電洞傳輸物質之使用量較佳為20～1000重量%，更佳為50～500重量%。 於本發明之光電轉換元件中，設置有吸附有光電轉換用增感色素之半導體層的電極(光電極)成為陰極，相對電極成為陽極。太陽光等光可自光電極側、相對電極側之任一側進行照射，較佳為自光電極側進行照射。藉由太陽光等之照射，色素吸收光而成為激發狀態從而釋出電子。該電子經由半導體層流動至外部而向相對電極移動。另一方面，釋出電子而成為氧化狀態之色素藉由經由電解質中之離子接收自相對電極供給之電子而返回至基態。藉由該循環而電流流動，從而作為光電轉換元件發揮功能。 於對本發明之光電轉換元件之特性進行評價時，進行短路電流、開路電壓、填充因數、光電轉換效率之測定。所謂短路電流，表示使輸出端子短路時於兩端子間流動之每1 cm² 之電流，所謂開路電壓，表示使輸出端子開放時之兩端子間之電壓。又，所謂填充因數，係指將最大輸出(電流與電壓之積)除以短路電流與開路電壓之積而得之值，主要受內部電阻影響。光電轉換效率係作為使將最大輸出(W)除以每1 cm² 之光強度(W)而得之值乘以100而進行百分比表示之值求出。 本發明之光電轉換元件可應用於色素增感太陽電池或各種光感測器等。本發明之色素增感太陽電池係藉由如下方式而獲得：以含有包含上述通式(1)所表示之增感色素之光電轉換用增感色素之光電轉換元件作為單元，將其單元進行必需片數排列而進行模組化，並設置特定之電氣配線。 [實施例] 以下，利用實施例具體地說明本發明，但本發明並不限定於以下之實施例。再者，於合成實施例中，化合物之鑑定係藉由¹ H-NMR分析(日本電子股份有限公司製造之核磁共振裝置，JNM-ECA-600或JNM-EX270)而進行。 [合成實施例1]增感色素(A-5)之合成 於經氮氣置換之反應容器中，放入甲苯165 mL、3,7-二溴二苯并噻吩8.00 g、雙(4-第三辛基苯基)胺10.12 g、鈉-第三丁氧化物3.37 g、三(二亞苄基丙酮)二鈀(0)1.07 g、及濃度0.2 mg/mL之三-第三丁基膦/甲苯溶液2.36 mL，於80℃下攪拌2小時。將反應液冷卻直至25℃為止之後，添加水380 mL、乙酸乙酯380 mL並進行攪拌，萃取有機層。將有機層利用飽和鹽水洗淨，利用硫酸鈉進行乾燥，進行減壓乾燥，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑(正己烷))進行精製，進行減壓乾燥，而獲得下述式(9)所表示之單溴化體化合物之白色固體(5.96 g)。 [化63]

於經氮氣置換之反應容器中，放入上述式(9)所表示之單溴化體1.20 g、及脫水四氫呋喃16 mL，於-72℃下一面進行攪拌，一面滴加1.6 M之正丁基鋰己烷溶液1.5 mL之後，進行1小時之反應後，滴加脫水二甲基甲醛0.3 mL，進行2小時反應。其後，將反應液放入至冰水中，利用二氯甲烷萃取有機層。對有機層進行水洗，進行分離，利用硫酸鎂進行乾燥，進行減壓濃縮。將殘渣藉由層析法(載體：矽膠，溶劑：己烷/甲苯＝9/1(體積比))進行精製，而獲得下述式(10)所表示之甲醯化體化合物之白色固體(0.78 g)。 [化64]

於經氮氣置換之反應容器中，添加乙酸25 mL、上述式(10)所表示之甲醯化體化合物0.362 g、氰乙酸0.297 g、乙酸銨0.027 g，於110℃下加熱攪拌21小時。將反應液冷卻直至25℃為止之後，添加水125 mL並進行攪拌，萃取有機層。將有機層利用水及飽和鹽水依序洗淨，將所獲得之有機層乾燥，而以紅色固體之形式獲得目標之增感色素(0.333 g、產率86%)。 對所獲得之紅色固體進行NMR分析，檢測以下之49個氫之訊號，鑑定為下述式(A-5)所表示之構造(未觀察到羧基之氫)。¹ H-NMR(600 MHz、CDCl₃ ) : δ (ppm) = 0.66 - 0.88 (18 H)、1.24 - 1.40 (12 H)、1.60 - 1.80 (4 H)、6.95 - 7.10 (4 H)、7.14 - 7.18 (1 H)、7.22 - 7.34 (4 H)、7.35 - 7.40 (1 H)、7.94 - 8.00 (1 H)、8.02 - 8.12 (2 H)、8.36 - 8.41 (1 H)、8.42 - 8.48 (1 H)。 [化65]

[合成實施例2]增感色素(A-22)之合成 於經氮氣置換之反應容器中，放入乙酸/甲苯＝5/2(體積比)混合液10.7 mL、合成實施例1中所獲得之式(10)所表示之甲醯化體化合物0.247 g、下述式(11)所表示之二氫茚酮化合物0.117 g，於90℃下攪拌3小時。將反應液冷卻直至25℃為止之後，添加水50 mL並進行攪拌，萃取有機層。將有機層利用水及飽和鹽水依序洗淨，進行乾燥，以紅褐色固體之形式獲得目標之增感色素(0.283 g、產率93%)。 [化66]

進行所獲得之紅褐色固體之NMR分析，檢測以下之52個氫之訊號，鑑定為下述式(A-22)所表示之構造(未觀察到羧基之氫)。¹ H – NMR (600 MHz、CDCl₃ ) : δ (ppm) = 0.64 - 0.85 (18 H)、1.22 - 1.45 (12 H)、1.70 - 1.91 (4 H)、6.95 - 7.00 (1 H)、7.01 - 7.05 (4 H)、7.22 - 7.30 (1 H)、7.35 - 7.40 (4 H)、7.90 - 8.00 (1 H)、8.04 - 8.07 (1 H)、8.20 - 8.24 (1 H)、8.27 - 8.33 (1 H)、8.34 - 8.38 (1 H)、8.39 - 8.41 (1 H)、8.54 - 8.59 (1 H)、9.10 - 9.15 (1 H)。 [化67]

[合成實施例3]增感色素(A-28)之合成 於經氮氣置換之反應容器中，放入甲苯200 mL、3,7-二溴二苯并噻吩10.78 g、下述式(12)所表示之胺化合物5.27 g、鈉-第三丁氧化物4.54 g、三(二亞苄基丙酮)二鈀(0)1.44 g、濃度0.2 mg/mL之三-第三丁基膦/甲苯溶液2.6 mL，於85℃下攪拌2小時。將反應液冷卻直至25℃為止後，添加水150 mL、乙酸乙酯500 mL並進行攪拌，萃取有機層。將有機層利用飽和鹽水洗淨，將所獲得之有機層利用硫酸鈉進行乾燥，進行減壓濃縮，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑：正己烷)進行精製，進行乾燥，而獲得下述式(13)所表示之單溴化體化合物之白色固體(5.32 g)。 [化68]

[化69]

於經氮氣置換之反應容器中放入N,N-二甲基甲醯胺34.5 mL、上述式(13)之單溴化體化合物2.30 g、氧氯化磷1.01 g，於25℃下攪拌90分鐘，於60℃下攪拌2小時。將反應液放入至冰水175 mL中，添加乙酸乙酯175 mL而萃取有機層。使用乙酸乙酯之萃取進行3次。將有機層利用硫酸鎂進行乾燥，將溶劑蒸餾去除，藉此，獲得粗產物。將所獲得之粗產物藉由管柱層析法(載體：矽膠，溶劑：甲苯)進行精製，而獲得下述式(14)所表示之化合物2.25 g(產率91%)之棕色固體。 [化70]

於經氮氣置換之反應容器中放入N,N-二甲基甲醯胺35 mL、上述式(14)所表示之化合物2.23 g、二苯基甲基膦酸二乙酯1.97 g、鉀第三丁氧化物1.00 g，於25℃下攪拌3小時。添加水90 mL而使反應停止之後，將反應物使用水/甲醇＝1/1(體積比)洗淨。將所獲得之粗產物藉由管柱層析法(載體：矽膠，溶劑：己烷/甲苯＝5/1(體積比))進行精製，而獲得下述式(15)所表示之單溴化體化合物2.89 g(產率97%)之黃色固體。 [化71]

於經氮氣置換之反應容器中，放入上述式(15)所表示之單溴化體0.500 g、脫水四氫呋喃10 mL，於-72℃下一面進行攪拌，一面滴加1.6 M之正丁基鋰/己烷溶液0.71 mL，進行2小時之反應。反應後，於反應液中滴加脫水二甲基甲醛0.3 mL後進行2小時反應。其後，將反應液放入至冰水中，添加二氯甲烷而萃取有機層。對有機層進行水洗，進行分離，利用硫酸鎂進行乾燥，進行減壓濃縮。將殘渣藉由層析法(載體：矽膠，溶劑：己烷/甲苯＝9/1(體積比))進行精製，而獲得下述式(16)所表示之甲醯化體化合物之黃色固體(0.196 g)。 [化72]

於經氮氣置換之反應容器中，放入乙酸/甲苯＝5/2(體積比)混合液8.5 mL、上述式(16)所表示之甲醯化體化合物0.188 g、上述式(11)所表示之二氫茚酮化合物0.102 g，於90℃下攪拌5小時。將反應液冷卻直至25℃為止之後，添加甲醇17 mL並進行攪拌，對反應物進行過濾。將反應物利用甲醇洗淨，將所獲得之有機層乾燥，而以黑色固體之形式獲得目標之增感色素(0.242 g、產率98%)。 進行所獲得之黑色固體之NMR分析，檢測以下之32個氫之訊號，鑑定為下述式(A-28)所表示之構造(未觀察到羧基之氫)。¹ H - NMR (600 MHz、CDCl₃ ) : δ (ppm) = 1.25 - 1.28 (1 H)、1.47 - 1.49 (1 H)、1.55 - 1.60 (1 H)、1.72 - 1.76(1 H)、1.80 - 1.89(1 H)、1.90 - 1.96(3 H)、6.60 - 6.70(1 H)、6.80 - 6.95(1 H)、7.00 - 7.10(2 H)、7.15 - 7.21(2 H)、7.24 - 7.35(5 H)、7.40 - 7.50(4 H)、7.80 - 7.90(1 H)、7.95 - 7.97(1 H)、8.00 - 8.09(1 H)、8.30 - 8.43(4 H)、8.58 - 8.62(1 H)、9.10 - 9.21(1 H)。 [化73]

[合成實施例4]增感色素(A-32)之合成 於經氮氣置換之反應容器中，放入甲苯41 mL、3,7-二溴二苯并噻吩2.2 g、下述式(17)所表示之胺化合物1.68 g、鈉-第三丁氧化物0.93 g、三(二亞苄基丙酮)二鈀(0)0.29 g、濃度0.2 mg/mL之三-第三丁基膦/甲苯溶液0.37 mL，於80℃下攪拌5小時。將反應液冷卻直至25℃為止之後，添加水30 mL、乙酸乙酯80 mL並進行攪拌，萃取有機層。將有機層利用飽和鹽水洗淨，利用硫酸鈉進行乾燥，進行減壓濃縮，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠、混合溶劑：正己烷/甲苯)進行精製，進行乾燥，而獲得下述式(18)所表示之單溴化體化合物之白黃色固體(1.08 g)。 [化74]

[化75]

於經氮氣置換之反應容器中，放入上述式(18)所表示之單溴化體1.00 g、脫水四氫呋喃20 mL，於-72℃下一面進行攪拌，一面滴加濃度1.6M之正丁基鋰/己烷溶液1.4 mL，進行3小時反應。反應後，於反應液中滴加脫水二甲基甲醛0.4 mL並進行2小時反應。其後，將反應液放入至冰水中，添加二氯甲烷而萃取有機層。對有機層進行水洗，進行分離，利用硫酸鎂進行乾燥，進行減壓濃縮。將殘渣藉由層析法(載體：矽膠，溶劑：己烷/甲苯＝9/1(體積比))進行精製，而獲得下述式(19)所表示之甲醯化體化合物之黃色固體(0.56 g)。 [化76]

於經氮氣置換之反應容器中，放入乙酸11 mL、上述式(19)所表示之甲醯化體化合物0.160 g、氰乙酸0.168 g、乙酸銨0.015 g，於105℃下攪拌7小時。將反應液冷卻直至25℃為止之後，添加水65 mL並進行攪拌，萃取有機層。將有機層利用水及飽和鹽水依序洗淨，進行乾燥，而以紅色固體之形式獲得目標之增感色素(0.155 g、產率89%)。 進行所獲得之紅色固體之NMR分析，檢測以下之25個氫之訊號，鑑定為下述式(A-32)所表示之構造(未觀察到羧基之氫)。¹ H - NMR (270 MHz、二甲基亞碸 (DMSO) - d₆ ) : δ (ppm) = 1.90 - 2.06 (4 H)、2.30 - 2.40 (4 H)、3.90 - 4.00 (1 H)、4.90 - 5.10 (1 H)、7.29 - 7.60 (8 H)、7.89 - 8.00 (1 H)、8.10 - 8.22 (1 H)、8.30 - 8.50 (4 H)、8.51 - 8.65 (1 H)。 [化77]

[合成實施例5]增感色素(A-33)之合成 於經氮氣置換之反應容器中，放入乙酸/甲苯＝5/2(體積比)混合液7.2 mL、上述式(19)所表示之甲醯化體化合物0.160 g、上述式(11)所表示之二氫茚酮化合物0.078 g，於90℃下攪拌6小時。將反應液冷卻直至25℃為止之後，添加甲苯15 mL並進行攪拌，對反應物進行過濾。將反應物利用甲醇洗淨，進行乾燥，而以黑色固體之形式獲得目標之增感色素(0.133 g、產率68%)。 進行所獲得之黑色固體之NMR分析，檢測以下之28個氫之訊號，鑑定為下述式(A-33)所表示之構造(未觀察到羧基之氫)。¹ H - NMR (270 MHz、DMSO - d₆ ) : δ (ppm) = 1.39 - 1.41 (1 H)、1.64 - 1.67 (1 H)、1.83 - 1.92 (2 H)、2.00 - 2.11 (2 H)、2.23 - 2.35 (3 H)、3.89 - 4.00 (1 H)、4.93 - 4.96 (1 H)、7.20 - 7.61 (8 H)、7.80 - 7.99 (2 H)、8.00 - 8.11 (1 H)、8.31 - 8.43 (4 H)、8.50 - 8.63 (1 H)、9.18 - 9.21 (1 H)。 [化78]

[合成實施例6]增感色素(A-34)之合成 於經氮氣置換之反應容器中，放入二甲基亞碸100 mL、上述式(9)所表示之單溴化體2.86 g、5'-甲醯基-2,2'-聯噻吩-5-硼酸1.25 g、碳酸鉀0.515 g、乙酸鈀(II)0.049 g、二(1-金剛烷基)-正丁基膦0.157 g，於80℃下攪拌3小時。將反應液冷卻直至25℃為止之後，添加水460 mL及乙酸乙酯460 mL並進行攪拌，萃取有機層。將有機層利用飽和鹽水洗淨，利用硫酸鈉進行乾燥，進行減壓濃縮，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑：己烷/甲苯＝1/2(體積比))進行精製，進行乾燥，而獲得下述式(20)所表示之甲醯化體化合物之黃褐色固體(2.86 g)。 [化79]

於經氮氣置換之反應容器中，放入乙酸/甲苯＝5/2(體積比)混合液35 mL、上述式(20)所表示之甲醯化體化合物0.770 g、上述式(11)所表示之二氫茚酮化合物0.300 g，於90℃下攪拌7小時。將反應液冷卻直至25℃為止之後，對反應液進行減壓濃縮，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑：氯仿/甲醇＝5/2(體積比))進行精製，而以黑色固體之形式獲得目標之增感色素(0.730 g、產率78%)。 對所獲得之黑色固體進行NMR分析，檢測以下之56個氫之訊號，鑑定為下述式(A-34)所表示之構造(未觀察到羧基之氫)。¹ H - NMR (600 MHz、DMSO - d₆ ) : δ (ppm) = 1.00 - 1.04 (18 H)、1.59 - 1.63 (12 H)、1.93 - 2.02 (4 H)、7.25 - 7.37 (5 H)、7.53 - 7.59 (4 H)、7.61 - 7.67 (2 H)、7.74 - 7.81 (2 H)、7.92 - 7.97 (1 H)、8.11 - 8.41 (6 H)、8.57 - 8.70 (2 H)。 [化80]

[合成實施例7]增感色素(A-35)之合成 於經氮氣置換之反應容器中，放入二甲基亞碸46 mL、上述式(13)所表示之單溴化體1.30 g、5-甲醯基-2-噻吩硼酸0.579 g、碳酸鉀0.364 g、乙酸鈀(II)0.035 g、二(1-金剛烷基)-正丁基膦0.111 g，於85℃下攪拌2小時。將反應液冷卻直至25℃為止之後，添加水200 mL及氯仿200 mL並進行攪拌，萃取有機層。將有機層利用飽和鹽水洗淨，利用硫酸鈉進行乾燥，進行減壓乾燥，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑：己烷/甲苯＝1/2(體積比))進行精製，進行乾燥，而獲得下述式(21)所表示之甲醯化體化合物之黃褐色固體(1.33 g)。 [化81]

於經氮氣置換之反應容器中，放入乙酸/甲苯＝1/3(體積比)混合液20 mL、上述式(21)所表示之甲醯化體化合物0.270 g、上述式(11)所表示之二氫茚酮化合物0.193 g，於90℃下攪拌8小時。將反應液冷卻直至25℃為止之後，對反應液進行減壓乾燥，而獲得粗產物。將粗產物藉由管柱層析法(載體：矽膠，溶劑：氯仿/甲醇＝5/1(體積比))進行精製，而以紅褐色固體之形式獲得目標之增感色素(0.280 g、產率75%)。 進行所獲得之紅褐色固體之NMR分析，檢測以下之24個氫之訊號，鑑定為下述式(A-35)所表示之構造(未觀察到羧基之氫)。¹ H - NMR (600 MHz、DMSO - d₆ ) : δ (ppm) = 1.06 - 1.19 (1 H)、1.31 - 1.35 (1 H)、1.55 - 1.59 (1 H)、1.72 - 1.76 (1 H)、1.91 - 2.02 (2 H)、3.78 - 3.82 (1 H)、4.78 - 4.82 (1 H)、6.69 - 6.73 (1 H)、7.00 - 7.12 (3 H)、7.37 - 7.41 (1 H)、7.75 - 8.39 (11 H)。 [化82]

[實施例1] 於塗佈有摻氟之氧化錫薄膜之玻璃基板上，藉由刮刀法塗佈氧化鈦膏(日揮觸媒化成股份有限公司製造，PST-18NR)。於110℃下乾燥1小時後，於450℃下進行30分鐘焙燒，而獲得膜厚7 μm之氧化鈦薄膜。繼而，將合成例1中所獲得之增感色素(A-5)及去氧膽酸以各者濃度成為100 μM及1 mM之方式溶解於乙腈/第三丁醇＝1/1(體積比)之混合溶劑中，而製備溶液50 mL，於該溶液中，將塗佈燒結有氧化鈦之玻璃基板於室溫下浸漬15小時，而吸附上述增感色素作為光電轉換用增感色素，從而製成光電極。 於塗佈有摻氟之氧化錫薄膜之玻璃基板上，使用自動精細塗佈機(日本電子股份有限公司製造之JFC-1600)藉由濺鍍法形成膜厚15 nm之鉑薄膜，而製成相對電極。 繼而，於光電極與相對電極之間隔著厚度60 μm之間隔片(熱熔膜)藉由熱熔使其等貼合，自預先形成於相對電極之孔注入電解液之後，將孔密封，而製作光電轉換元件。作為電解液，使用碘化鋰0.1 M、碘化二甲基丙基咪唑鎓0.6 M、碘0.05 M、4-第三丁基吡啶0.5 M之3-甲氧基丙腈溶液。 自上述光電轉換元件之光電極側，照射利用模擬太陽光照射裝置(Bunkoukeiki股份有限公司製造之OTENTO-SUN III型)產生之光，使用電源電錶(KEITHLEY製造，Model 2400 General-Purpose SourceMeter)測定電流-電壓特性。光之強度係調整為100 mW/cm² 。又，照射光20小時之後亦進行光電轉換效率之測定，對特性變化進行評價。將測定結果彙總表示於表1。 [實施例2～實施例9] 作為光電轉換用增感色素，分別使用表1所示之增感色素代替(A-5)，除此以外，與實施例1同樣地製作光電轉換元件，測定電流-電壓特性。又，照射光20小時之後亦進行光電轉換效率之測定，對特性變化進行評價。將測定結果彙總表示於表1。 [比較例1～比較例4] 作為光電轉換用增感色素，使用不屬於本發明且先前技術(專利文獻4～6)中所揭示之以下之式(B-1)～(B-4)所示之增感色素代替(A-5)，除此以外，與實施例1同樣地製作光電轉換元件，測定電流-電壓特性。又，照射光20小時之後亦進行光電轉換效率之測定，對特性變化進行評價。將測定結果彙總表示於表1。 [化83]

[化84]

[化85]

[化86]

[表1]

根據表1之結果判明：藉由使用包含本發明之增感色素之光電轉換用增感色素，而可獲得光電轉換效率較高且即便將光照射持續進行長時間亦可維持較高之光電轉換效率之光電轉換元件。另一方面，使用比較例之光電轉換用增感色素之光電轉換元件之光電轉換效率不充分。 參照特定之態樣對本發明進行了詳細說明，但業者應當理解可不脫離本發明之精神及範圍而進行各種變更及修正。 再者，本申請案係基於2016年9月27日提出申請之日本專利申請案(日本專利特願2016-188633)，其全部內容係藉由引用而被援用。又，此處所引用之全部參照係作為整體併入本文。 [產業上之可利用性] 包含本發明之增感色素之光電轉換用增感色素作為高效率且高耐久性之光電轉換元件以及色素增感太陽電池有用，可製成可將太陽光能高效地轉換為電能之太陽電池而提供清潔能源。Hereinafter, embodiments of the present invention will be described in detail. The sensitizing dye for photoelectric conversion of the present invention is used as a sensitizer in a dye-sensitized photoelectric conversion element. The photoelectric conversion element of the present invention is formed by arranging a photoelectrode formed by adsorbing a dye on a semiconductor layer on a conductive support and a counter electrode interposing an electrolyte layer facing each other. Hereinafter, the sensitizing dye represented by the general formula (1) will be specifically described, but the present invention is not limited to these. In the general formula (1) ^{, specific examples of the "halogen atom" represented by R 1} to R ⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. In the general formula (1), as the "linear or branched alkyl group having 1 to 6 carbon atoms" represented by ^{R 1} to R ^{6, specifically, methyl, ethyl, and normal} Propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-pentyl, n-hexyl, isohexyl, etc. In the general formula (1), as the "linear or branched alkoxy group having 1 to 6 carbon atoms" represented by ^{R 1} to R ^{6, specific examples include methoxy and ethoxy} Group, propoxy group, isopropoxy group, n-butoxy group, second butoxy group, tertiary butoxy group, n-pentoxy group, n-hexoxy group, isohexoxy group, etc. In the general formula (1), R ¹ to R ^{6 are} preferably hydrogen atoms, or linear or branched alkyl groups having 1 to 6 carbon atoms. For reasons such as easy availability of raw materials, they are more preferably A hydrogen atom. In the general formula (1), as the "linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents" represented by ^{R 7} or R ^{8 "the number of carbon atoms is 1 to} 20 linear or branched alkyl", specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, second butyl, tertiary butyl, n-hexyl , Isohexyl, etc. In the general formula (1), as the "substituent" in the "linear or branched alkyl group with 1 to 20 carbon atoms which may have substituents" represented by ^{R 7} or R ^{8, specifically} Examples include halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms; and the number of carbon atoms such as methoxy, ethoxy, propoxy, tert-butoxy, pentyloxy, and hexyloxy groups. 1-19 linear or branched alkoxy; phenyl, naphthyl, anthryl, phenanthryl, pyrenyl, and other carbon 6-19 aryl groups; dimethylamino, diethylamino , Ethylmethylamino, methylpropylamino, di-tertiary butylamino, diphenylamino and other linear or branched alkyl groups with 1 to 18 carbon atoms , Or a disubstituted amino group which is a substituent of an aryl group with 6 to 18 carbon atoms; hydroxyl group; carboxyl group; carboxylic acid ester groups such as methyl ester group and ethyl ester group; cyano group, etc. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (1), as the "cycloalkyl group with 3 to 20 carbon atoms" in the "cycloalkyl group with 3 to 20 carbon atoms" represented by ^{R 7} or R ^8, Specifically, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc. can be mentioned. In the general formula (1), as the "substituent" in the "substitutable cycloalkyl group having 3 to 20 carbon atoms" represented by ^{R 7} or R ^{8, specifically, fluorine can be cited} Halogen atoms such as atom, chlorine atom, bromine atom, iodine atom; methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl and other linear carbon atoms with 1 to 17 or Branched chain alkyl; methoxy, ethoxy, propoxy, tert-butoxy, pentoxy, hexyloxy and other linear or branched alkoxy groups with 1 to 17 carbon atoms Group; aryl groups with 6 to 17 carbon atoms such as phenyl, naphthyl, anthryl, phenanthryl, pyrenyl, etc.; dimethylamino, diethylamino, ethylmethylamino, methylpropylamino , Di-tertiary butylamino group, diphenylamino group, etc. have substitutions selected from linear or branched alkyl groups with 1 to 16 carbon atoms, or aryl groups with 6 to 16 carbon atoms The disubstituted amino group of the group; hydroxyl group; carboxyl group; carboxylic acid ester groups such as carbomethoxy group and carboethoxy group; vinyl group such as vinyl group, vinylidene group, phenyl vinyl group, diphenyl vinyl group, etc.; cyano group, etc. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (1), as the "linear or branched alkenyl group having 2 to 20 carbon atoms which may have substituents" represented by ^{R 7} or R ^{8 "the number of carbon atoms is 2 to} 20 linear or branched alkenyl", specifically, vinyl, allyl, isopropenyl, 2-butenyl, 1-hexenyl, or plural of these alkenyl groups A straight-chain or branched-chain base formed by bonding. In the general formula (1), as the "substituent" in the "linear or branched alkenyl group with 2 to 20 carbon atoms which may have substituents" represented by ^{R 7} or R ^{8, specifically} For example, halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; carbon atoms such as methoxy, ethoxy, propoxy, tert-butoxy, n-pentyloxy, n-hexyloxy, etc. 1-18 linear or branched alkoxy; phenyl, naphthyl, anthracenyl, phenanthryl, pyrenyl and other carbon 6-18 aryl groups; dimethylamino, diethylamino , Ethylmethylamino, methylpropylamino, di-tertiary butylamino, diphenylamino and other linear or branched alkyl groups with 1-17 carbon atoms , Or a di-substituted amino group as a substituent in an aryl group with 6 to 17 carbon atoms; hydroxyl group; carboxyl group; carboxylic acid ester groups such as carbomethoxy group and carboethoxy group; cyano group, etc. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (1), as the "aralkyl group with 7 to 26 carbon atoms" in the "aralkyl group with 7 to 26 carbon atoms" represented by ^{R 7} or R ^8, Specifically, benzyl, phenethyl, 3-phenylpropyl, benzhydryl, trityl, 1-naphthylmethyl, 2-naphthylmethyl, 2-naphthylethyl , 2-pyrenylethyl, etc. In the general formula (1), as the "substituent" in the "aralkyl group having 7 to 26 carbon atoms which may have a substituent" represented by ^{R 7} or R ^{8, specifically, fluorine can be cited} Halogen atoms such as atom, chlorine atom, bromine atom, iodine atom; methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, hexyl and other linear carbon atoms with 1 to 19 or Branched chain alkyl; methoxy, ethoxy, propoxy, tert-butoxy, n-pentoxy, n-hexyloxy and other linear or branched alkyls with 1 to 19 carbon atoms Oxy group; dimethylamino group, diethylamino group, ethylmethylamino group, methylpropylamino group, di-tertiary butylamino group, diphenylamino group, etc. have a number of carbon atoms selected from 1 to 18 straight-chain or branched-chain alkyl groups, or disubstituted amino groups as substituents of aryl groups with 6 to 19 carbon atoms; hydroxyl groups; carboxyl groups; carboxylic acid ester groups such as methyl ester and ethyl ester groups; Vinyl groups such as vinyl groups, vinylidene groups, phenyl vinyl groups, diphenyl vinyl groups, etc.; cyano groups, etc. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (1), as the "aryl group with 6 to 30 carbon atoms" in the "aryl group with 6 to 30 carbon atoms" represented by ^{R 7} or R ^{8, specifically} For example, phenyl, naphthyl, biphenyl, anthryl, phenanthryl, pyrenyl, triphenyl, indenyl, stilbyl, etc. can be mentioned. Here, in the present invention, the "aryl group" refers to an aromatic hydrocarbon group and a condensed polycyclic aromatic group. Among them, phenyl or naphthyl is preferred, and phenyl is more preferred. In the general formula (1), as the "substituent" in the "optionally substituted aryl group with 6 to 30 carbon atoms" represented by ^{R 7} or R ^{8, specific examples include: fluorine atom} , Chlorine atom, bromine atom, iodine atom and other halogen atoms; methyl, ethyl, n-propyl, isopropyl, n-butyl, tertiary butyl, n-hexyl, tertiary octyl and other halogen atoms with 1 to 24 carbon atoms The linear or branched alkyl group; methoxy, ethoxy, propoxy, tertiary butoxy, n-pentyloxy, n-hexyloxy and other linear chain with 1 to 24 carbon atoms or Branched alkoxy; aryl groups with 6 to 24 carbon atoms such as phenyl, naphthyl, anthryl, phenanthryl, pyrenyl, etc.; dimethylamino, diethylamino, ethylmethylamino, Methyl propyl amino group, di-tertiary butyl amino group, diphenyl amino group, etc. have a linear or branched alkyl group selected from 1 to 23 carbon atoms, or 6 to 23 carbon atoms The double substituted amino group of the substituent in the aryl group; hydroxyl group; carboxyl group; carboxylic acid ester group such as methyl ester group and ethyl ester group; vinyl group, vinylidene group, phenyl vinyl group, diphenyl vinyl group, etc. Group; cyano etc. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (1), R ⁷ and R ^{8 are} preferably a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, or a carbon atom number of 3 which may have a substituent -20 cycloalkyl group, or aryl group with 6 to 30 carbon atoms which may have substituents, more preferably cycloalkyl group with 3 to 20 carbon atoms which may have substituents, or may have substituents The aryl group with 6 to 30 carbon atoms. In the general formula (1), R ⁷ and R ⁸ represent the substituents as described above, and R ⁷ and R ⁸ may also be through a single bond (R ⁷ -R ⁸ ) or a bond through an oxygen atom (R ^7- OR ⁸ ) or bond with each other via a sulfur atom (R ⁷ -SR ⁸ ) to form a ring. In the general formula (1), X represents a monovalent group, preferably a monovalent group represented by the above general formula (X1), (X2) or (X3). X is more preferably a monovalent group represented by the above general formula (X1) or (X3), and particularly preferably a monovalent group represented by the above general formula (X3). In the general formula (X1), ^{the "acidic group" represented by R 9} specifically includes a carboxyl group, a sulfonic acid group, a phosphoric acid group, a hydroxamic acid group, a phosphonic acid group, a boronic acid group, and a phosphinic acid group. , Silanol group, etc. Among them, a carboxyl group or a phosphonic acid group is preferred, and a carboxyl group is more preferred. In the general formula (X2), L or M represents "a linear or branched alkyl group having 1 to 6 carbon atoms with one or two acidic groups as a substituent", or "not In the "linear or branched alkyl group with 1 to 6 carbon atoms" in the "substituted linear or branched alkyl group with 1 to 6 carbon atoms", specifically, examples include a Group, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, n-hexyl, isohexyl, etc. Among these, a linear or branched alkyl group having 1 to 3 carbon atoms is preferable, and a methyl group or an ethyl group is more preferable. In the general formula (X2), as "acidic" in the "linear or branched alkyl group with 1 to 6 carbon atoms having 1 or 2 acidic groups as substituents" represented by L or M The "group" specifically includes a carboxyl group, a sulfonic acid group, a phosphoric acid group, a hydroxamic acid group, a phosphonic acid group, a boric acid group, a phosphinic acid group, a silanol group, and the like. Among them, a carboxyl group or a phosphonic acid group is preferred, and a carboxyl group is more preferred. When the number of "acidic groups" is one, the substitution position of the "acidic group" is preferably the end of the alkyl group, and when the number of "acidic groups" is two, it is preferably the two Among the "acidic groups", the substitution position of at least one "acidic group" is the end of the alkyl group. In the general formula (X2), as the "linear or branched alkyl group with 1 to 6 carbon atoms having 1 or 2 acidic groups as substituents" represented by L or M, it is preferably A linear or branched alkyl group having 1 to 3 carbon atoms with one or two acidic groups selected from the group consisting of carboxyl and phosphonic acid groups as substituents, more preferably having one or two carboxyl groups as substituents The substituent is methyl or ethyl. In the general formula (X2), at least either of L or M is "a linear or branched alkyl group with 1 to 6 carbon atoms having 1 or 2 acidic groups as a substituent". Here, p represents an integer from 0 to 2. When p is 0, L does not exist, therefore, M becomes a linear chain with 1 to 6 carbon atoms with 1 or 2 acidic groups as substituents Or branched alkyl". In addition, when p is 2, at least one of the two existing L or M is "a linear chain with 1 to 6 carbon atoms having 1 or 2 acidic groups as substituents, or "Branched alkyl" is sufficient. In the general formula (X3), as ^{the "acidic group" in the "hydrogen atom or acidic group" represented by R 11} and R ¹² , specific examples include carboxyl group, sulfonic acid group, phosphoric acid group, and hydroxamic acid group , Phosphonic acid group, boric acid group, phosphinic acid group, silanol group, etc. Among them, a carboxyl group or a phosphonic acid group is preferred, and a carboxyl group is more preferred. In the general formula (X3), as the "linear or branched alkyl group having 1 to 18 carbon atoms which may have substituents" represented by ^{R 13} and R ^{14 "the number of carbon atoms is 1 to} 18 "Straight-chain or branched-chain alkyl", specifically, include: methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc. Straight-chain alkyl groups; branched-chain alkyl groups such as isopropyl, isobutyl, second butyl, tertiary butyl, and isooctyl. In the general formula (X3), as "the number of carbon atoms is 1" in the "linear or branched alkoxy group having 1 to 18 carbon atoms which may have substituents" represented by ^{R 13} and R ¹⁴ ～18 linear or branched alkoxy", specifically, methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, heptoxy , Octyloxy, nonoxy, decyloxy and other straight-chain alkoxy; isopropoxy, isobutoxy, second butoxy, tertiary butoxy, isooctyloxy and other branched Shape of the alkoxy group. In the general formula (X3), as the "linear or branched alkenyl group having 2 to 18 carbon atoms which may have substituents" represented by ^{R 13} and R ^{14 "the number of carbon atoms is 2 to} 18 "Straight-chain or branched alkenyl group", specific examples include vinyl, allyl, isopropenyl, 2-butenyl, 1-hexenyl and other alkenyl groups, or these alkenyl groups A linear or branched alkenyl group formed by a plurality of bonding groups. In the general formula (X3), as R ¹³ and R ¹⁴ represented by "a linear or branched alkyl group having 1 to 18 carbon atoms" and "a substituted carbon number 1 The "substituent" in the "linear or branched alkoxy group of ～18" or "the linear or branched alkenyl group having 2 to 18 carbon atoms with substituents", specifically, Examples include: halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; cyano group; hydroxyl group; nitro group; nitroso group; thiol group; cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclo Cycloalkyl groups with 3-16 carbon atoms such as octyl; methoxy, ethoxy, propoxy, butoxy, pentoxy, hexyloxy, heptoxy, octyloxy, nonoxy, A straight-chain alkoxy group with 1-16 carbon atoms such as decyloxy group; I-propoxy group, isobutoxy group, second butoxy group, tertiary butoxy group, isooctyloxy group and other carbon atoms 3 -16 branched alkoxy; cyclopropoxy, cyclobutoxy, cyclopentyloxy, cyclohexyloxy and other cycloalkoxy groups with 3 to 16 carbon atoms; phenyl, naphthyl, bi Phenyl, anthryl, phenanthryl, pyrenyl, indenyl, stilbene and other aryl groups with 6 to 16 carbon atoms; unsubstituted amino groups; methylamino groups, dimethylamino groups, diethylamino groups, ethyl Amino groups with 1-16 substituents such as methylamino, methylpropylamino, di-tertiary butylamino, diphenylamino, etc.; carboxyl; methyl ester, ethyl ester Carboxylic acid ester groups and the like. These "substituents" may include only one or plural, and when plural are included, they may be the same or different from each other. In addition, these "substituents" may further have the substituents exemplified above. In the general formula (X3), R ¹³ and R ^{14 are} preferably a hydrogen atom or a linear or branched alkyl group having 1 to 18 carbon atoms which may have a substituent, and more preferably a hydrogen atom. In the general formula (X3), R ¹³ and R ¹⁴ may also be bonded to each other to form a ring, and these rings may also be bonded to each other by a single bond or through a bond of any atom of a nitrogen atom, an oxygen atom, or a sulfur atom. To form a ring. In the general formula (X3), r represents the number of thienyl groups. Here, the thienyl group has a role of transporting (transmitting) electrons excited by the dye moiety to the linking group of the indanone group as the electron withdrawing part. r represents an integer of 0-4, preferably 0-2. Among the sensitizing dyes of the present invention represented by the general formula (1), the sensitizing dye containing a carboxyl group or a phosphonic acid group as an acidic group can be easily adsorbed on the surface of the semiconductor layer, therefore, it is helpful to use the sensitizing dye The photoelectric conversion characteristics of the photoelectric conversion element of the pigment are further improved. The sensitizing dye of the present invention represented by the general formula (1) includes all possible stereoisomers. Any isomer can be preferably used as the sensitizing dye in the present invention. For example, in the above general formula (1), R ¹ to R ⁶ are hydrogen atoms and X is a monovalent group represented by the above general formula (X1), the sensitizing dye of the present invention is deemed to include the following general formula (2 ) And (3). [化5]

[化6]

Specific examples of the sensitizing dye of the present invention represented by the general formula (1) are shown in the following formulas (A-1) to (A-51), but the present invention is not limited to these. The following exemplified compounds represent one example of possible stereoisomers, and are deemed to include all other stereoisomers. In addition, it may be a mixture of two or more stereoisomers. [化7]

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The sensitizing dye of the present invention represented by the general formula (1) can be synthesized using a known method. In the general formula (1), when all of R ¹ to R ⁶ are hydrogen atoms, synthesis can be carried out in the following manner, for example. By performing a Buchwald-Hartwig reaction of 3,7-dibromodibenzothiophene represented by the following formula (4) with an amine compound represented by the following formula (5), the following formula (6) can be obtained The intermediate represented is the monobromide. Furthermore, the bromo group (-Br) of the general formula (6) is converted into a methyloyl group (-CHO) according to a conventional method or by performing a cross-coupling reaction such as Suzuki coupling with a boronic acid having a corresponding substituent. The formazan compound represented by the following general formula (7) was obtained. Among them, in the following general formulas (5) to (7), R ⁷ , R ⁸ , R ¹³ and R ¹⁴ have the same meanings as the symbols in the general formula (1), and similarly, r represents 0-4 Integer. The formazan compound (r=0) represented by the following general formula (7) can be, for example, captured by the bromide represented by the general formula (6) by using N,N-dimethylformamide (DMF) It is synthesized by exchanging aryl lithium with metal halide such as butyl lithium. The synthesis of the formazan compound (r = 1 to 4) represented by the following general formula (7) can use, for example, 5-methanyl-2-thiophene boronic acid or 5'-methanyl-2,2'-bithiophene A boronic acid having a thiophene ring containing a formyl group and corresponding substituents, such as 5-boronic acid, undergoes a cross-coupling reaction to synthesize the formyl compound represented by the general formula (7). [化58]

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[化61]

X in the general formula (1) of the present invention is a monovalent sensitizing dye represented by the general formula (X1), (X2) or (X3). The general formula ( 7) The intermediate (formaldehyde) and the corresponding compound are synthesized by the condensation reaction. Specifically, it can be combined with cyanoacetic acid, etc. (X is the case of the above general formula (X1)), rhodanine compounds such as rhodanine-3-acetic acid (X is the case of the above general formula (X2)), Or it can be synthesized by the condensation reaction of the indanone compound represented by the following formula (8) (X is the case where X is the above-mentioned general formula (X3)). [化62]

Furthermore, with regard to the above-mentioned formula (4) or (5), etc. used as the starting material, commercially available ones can be used, or those synthesized by a known method can also be used. The indanone compound represented by the general formula (8) can be easily synthesized by the method described in Patent Documents 8-10. In addition, when R ¹ to R ⁶ are substituents other than hydrogen atoms, the same reaction as above can be performed by using the corresponding dibromodibenzothiophene derivatives, etc., to synthesize the formula (1) Represents the sensitizing pigment of the present invention. As the purification method of the sensitizing pigment compound of the present invention represented by the general formula (1), there can be mentioned: purification by column chromatography; adsorption purification by silica gel, activated carbon, activated clay, etc.; Well-known methods such as recrystallization and crystallization. In addition, the identification of these compounds can be performed by nuclear magnetic resonance analysis (NMR) and the like. The sensitizing dye of the present invention may be used alone or in combination of two or more kinds. In addition, the sensitizing dye of the present invention can be used in combination with other sensitizing dyes not belonging to the present invention. Specific examples of other sensitizing dyes include ruthenium complexes, coumarin dyes, cyanine dyes, merocyanine dyes, rhodanine dyes, phthalocyanine dyes, porphyrin dyes, and

A sensitizing dye other than the sensitizing dye represented by the above general formula (1), such as a dye. When the sensitizing dye of the present invention is used in combination with these other sensitizing dyes, it is preferable to set the usage amount of the other sensitizing dye to 10 to 200% by weight relative to the sensitizing dye of the present invention. It is preferably set to 20 to 100% by weight. The sensitizing dye of the present invention can be used as a photoreceptor, photocatalyst, optical functional material, etc. for various imaging materials such as silver halide, zinc oxide, and titanium oxide. It can also be used as a dye-sensitized photoelectric conversion element. Applications such as sensitizing dyes used in photoelectric conversion. In addition, the energy excited by the sensitizing dye of the present invention can be applied to the light-energy of next-generation solar cells such as organic thin-film solar cells or perovskite solar cells and next-generation storage batteries that are combined with other photoelectric conversion elements. (Electricity, heat, information, etc.) conversion components. For example, in the present invention, the method of manufacturing a dye-sensitized photoelectric conversion element is not particularly limited, and it is preferable to form a semiconductor layer on a conductive support (electrode) to adsorb the sensitizing dye for photoelectric conversion of the present invention. (Supported) A method of fabricating a photoelectrode on the semiconductor layer (refer to FIG. 1). As a method of adsorbing the pigment, generally speaking, a method of immersing the semiconductor layer in a solution obtained by dissolving the pigment in a solvent for a long time is a method. When two or more sensitizing dyes for photoelectric conversion of the present invention are used in combination, or when sensitizing dyes for photoelectric conversion of the present invention are used together with other sensitizing dyes, a mixture of all the dyes used can be prepared Solution and immerse the semiconductor layer in it, and also prepare separate solutions for each dye, and immerse the semiconductor layer in each solution sequentially. In the present invention, as a conductive support, in addition to a metal plate, it can be used for a glass substrate or a plastic substrate provided with a conductive layer with a conductive material on the surface. Specific examples of conductive materials include metals such as gold, silver, copper, aluminum, and platinum, conductive transparent oxide semiconductors such as fluorine-doped tin oxide, indium-tin composite oxide, etc., and carbon is preferably used. Glass substrate coated with fluorine-doped tin oxide film. In the present invention, specific examples of semiconductors forming the semiconductor layer include titanium oxide, zinc oxide, tin oxide, indium oxide, zirconium oxide, tungsten oxide, tantalum oxide, iron oxide, gallium oxide, nickel oxide, and yttrium oxide. Metal oxides such as titanium sulfide, zinc sulfide, zirconium sulfide, copper sulfide, tin sulfide, indium sulfide, tungsten sulfide, cadmium sulfide, silver sulfide and other metal sulfides; titanium selenide, zirconium selenide, indium selenide, selenide Metal selenides such as tungsten; single semiconductors such as silicon and germanium. These semiconductors can be used not only singly, but also a mixture of two or more kinds. In the present invention, it is preferable to use one or two or more selected from titanium oxide, zinc oxide, and tin oxide as the semiconductor. The aspect of the semiconductor layer in the present invention is not particularly limited, but it is preferably a thin film having a porous structure containing fine particles. With the porous structure, etc., the substantial surface area of the semiconductor layer becomes larger, and if the amount of dye adsorption to the semiconductor layer increases, a highly efficient photoelectric conversion element can be obtained. The semiconductor particle size is preferably 5 to 500 nm, more preferably 10 to 100 nm. The thickness of the semiconductor layer is usually 2-100 μm, more preferably 5-20 μm. As a method of forming a semiconductor layer, a paste containing semiconductor fine particles may be applied to a conductive substrate by a wet coating method such as a spin coating method, a doctor blade method, a press roll method, or a screen printing method, and then baked by baking. The method of removing the solvent or additives to form a film, or the method of forming a film by a sputtering method, an evaporation method, an electroplating method, an electrodeposition method, a microwave irradiation method, etc., is not limited to these. In the present invention, a commercially available product may be used for the paste containing semiconductor fine particles, and a paste prepared by dispersing commercially available semiconductor fine powder in a solvent may also be used. Specific examples of the solvent used when preparing the paste include: water; alcohol-based solvents such as methanol, ethanol, and isopropanol; ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; n-hexane Hydrocarbon solvents, such as cyclohexane, benzene, toluene, etc., are not limited to these. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds. In the present invention, as a method for dispersing the semiconductor fine powder in a solvent, it can be ground using a mortar, etc., or a ball mill, a paint conditioner, a vertical bead mill, a horizontal bead mill, and a grinder can also be used. Wait for the dispersion machine. When preparing the paste, it is preferable to add a surfactant or the like to prevent aggregation of the semiconductor particles, and it is preferable to add a thickening agent such as polyethylene glycol to increase the viscosity. The sensitizing dye for photoelectric conversion of the present invention is adsorbed on the surface of the semiconductor layer by immersing the semiconductor layer in the dye solution and placing it at room temperature for 30 minutes to 100 hours or under heating conditions for 10 minutes to 24 hours To proceed, it is preferable to leave it at room temperature for 10 to 20 hours. In addition, the pigment concentration in the pigment solution is preferably 10 to 2000 μm, more preferably 50 to 500 μm. Specific examples of the solvent used when the sensitizing dye for photoelectric conversion of the present invention is adsorbed on the surface of the semiconductor layer include alcohol-based solvents such as methanol, ethanol, isopropanol, and tert-butanol; acetone, methyl Ketone solvents such as ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl formate, ethyl acetate, and n-butyl acetate; diethyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 1,3 -Ether solvents such as dioxolane; amine solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone; acetonitrile, Nitrile solvents such as methoxyacetonitrile and propionitrile; halogenated hydrocarbon solvents such as dichloromethane, chloroform, tribromomethane, and o-dichlorobenzene; hydrocarbon solvents such as n-hexane, cyclohexane, benzene, and toluene, but not limited In these. These solvents can be used alone or in the form of a mixed solvent of two or more kinds. Among these solvents, it is preferable to use one or two or more selected from methanol, ethanol, tertiary butanol, acetone, methyl ethyl ketone, tetrahydrofuran, and acetonitrile. When the sensitizing dye for photoelectric conversion of the present invention is adsorbed on the surface of the semiconductor layer, it can also dissolve cholic acid derivatives such as cholic acid, deoxycholic acid, chenodeoxycholic acid, cholic acid, dehydrocholic acid, etc. In the pigment solution and co-adsorbed with the pigment. By using cholic acid or a cholic acid derivative, the association of the pigments with each other is suppressed, so that electrons can be efficiently injected from the pigments into the semiconductor layer in the photoelectric conversion element. In the case of using cholic acid or a cholic acid derivative, the concentration of them in the pigment solution is preferably 0.1-100 mM, more preferably 0.5-10 mM. The counter electrode (electrode) used in the photoelectric conversion element of the present invention is not particularly limited as long as it has conductivity. In order to promote the oxidation-reduction reaction of redox ions, it is preferable to use a conductive material with a catalyst function . As a specific example of this conductive material, platinum, rhodium, ruthenium, carbon, etc. are mentioned, but it is not limited to these. In the present invention, it is particularly preferable to use a thin film of platinum formed on a conductive support as a counter electrode. In addition, as a method of forming a conductive film, a paste containing a conductive material can be applied to a conductive substrate by a wet coating method such as a spin coating method, a doctor blade method, a roll method, and a screen printing method. Afterwards, the method of film formation by removing the solvent or additives by baking, or the method of film formation by sputtering, vapor deposition, electroplating, electrodeposition, microwave irradiation, etc., but it is not limited In these. In the photoelectric conversion element of the present invention, an electrolyte is filled between a pair of opposed electrodes to form an electrolyte layer. As the electrolyte used, a redox electrolyte is preferable. Examples of the redox electrolyte include redox ion pairs such as iodine, bromine, tin, iron, chromium, and anthraquinone, but are not limited to these. Among these, iodine-based electrolytes and bromine-based electrolytes are preferred. In the case of an iodine-based electrolyte, for example, a mixture of potassium iodide, lithium iodide, dimethylpropylimidazolium iodide, etc., and iodine can be used. In the present invention, it is preferable to use an electrolyte solution obtained by dissolving these electrolytes in a solvent. The concentration of the electrolyte in the electrolyte is preferably 0.05-5 M, more preferably 0.2-1 M. Examples of solvents that dissolve the electrolyte include nitrile solvents such as acetonitrile, methoxyacetonitrile, propionitrile, 3-methoxypropionitrile, and benzonitrile; diethyl ether, 1,2-dimethoxyethane, Ether-based solvents such as tetrahydrofuran; amine-based solvents such as N,N-dimethylformamide and N,N-dimethylacetamide; carbonate-based solvents such as ethylene carbonate and propylene carbonate; γ- Lactone-based solvents such as butyrolactone and γ-valerolactone are not limited to these. These solvents can be used alone or in the form of a mixed solvent of two or more kinds. Among these solvents, nitrile solvents are preferred. In the present invention, in order to further increase the open circuit voltage and the filling factor of the dye-sensitized photoelectric conversion element, the above-mentioned electrolyte solution may contain an amine compound. Examples of amine compounds include 4-tert-butylpyridine, 4-methylpyridine, 2-vinylpyridine, N,N-dimethyl-4-aminopyridine, N,N-dimethylaniline, N-methylbenzimidazole and so on. The concentration of the amine compound in the electrolyte is preferably 0.05-5 M, more preferably 0.2-1 M. As the electrolyte in the photoelectric conversion element of the present invention, a gel electrolyte obtained by adding a gelling agent or a polymer, or a solid electrolyte using a polymer such as a polyethylene oxide derivative can also be used. By using gel electrolyte and solid electrolyte, the volatilization of the electrolyte can be reduced. In the photoelectric conversion element of the present invention, a solid charge transport layer can also be formed between a pair of opposed electrodes instead of the electrolyte. The charge transport material contained in the solid charge transport layer is preferably a hole transport material. Specific examples of the charge transport material include inorganic hole transport materials such as copper iodide, copper bromide, and copper thiocyanide, polypyrrole, polythiophene, polyparaphenylene vinylene, polyvinylcarbazole, polyaniline, and Organic hole transport materials such as diazole derivatives, triphenylamine derivatives, pyrazoline derivatives, stilbenone derivatives, hydrazone compounds, and stilbene compounds, but are not limited to these. Preferably, the solid charge transport layer contains a lithium compound such as lithium bis(trifluoromethanesulfonyl)imide or lithium diisopropylimide, and a base such as 4-tert-butylpyridine or 2-pentylpyridine. Amine compounds and the like are used as additives. In addition, in order to improve the conductivity, an oxidizing agent used to make a part of the organic hole transport material become a radical cation may be added. Examples of the oxidizing agent include cobalt such as tris(2-(1H-pyrazol-1-yl)-4-tert-butylpyridine) cobalt(III) tris(bis(trifluoromethylsulfonyl)imide) Complexes and so on. In the present invention, when an organic hole transport material is used to form a solid charge transport layer, a film-forming adhesive resin can also be used in combination. Specific examples of film-forming adhesive resins include polystyrene resins, polyvinyl acetal resins, polycarbonate resins, polycarbonate resins, polyester resins, polyphenylene ether resins, polyarylate resins, and alkyd resins. Resin, acrylic resin, phenoxy resin, etc. are not limited to these. These resins can be used singly or in the form of a copolymer by mixing one or more types. The usage amount of the binder resin relative to the organic hole transport material is preferably 20-1000% by weight, more preferably 50-500% by weight. In the photoelectric conversion element of the present invention, the electrode (photoelectrode) provided with the semiconductor layer on which the sensitizing dye for photoelectric conversion is adsorbed becomes the cathode, and the counter electrode becomes the anode. Light such as sunlight can be irradiated from either the photoelectrode side or the opposing electrode side, and it is preferably irradiated from the photoelectrode side. When irradiated by sunlight or the like, the pigment absorbs light and becomes an excited state to release electrons. The electrons flow to the outside through the semiconductor layer and move to the counter electrode. On the other hand, the dye that releases electrons and becomes an oxidized state returns to the ground state by receiving electrons supplied from the counter electrode through ions in the electrolyte. With this circulation, current flows and functions as a photoelectric conversion element. When evaluating the characteristics of the photoelectric conversion element of the present invention, short-circuit current, open-circuit voltage, fill factor, and photoelectric conversion efficiency were measured. ^{The so-called short-circuit current refers to the current per 1 cm 2} that flows between the two terminals when the output terminal is short-circuited, and the so-called open circuit voltage refers to the voltage between the two terminals when the output terminal is opened. Also, the so-called fill factor refers to the value obtained by dividing the maximum output (product of current and voltage) by the product of short-circuit current and open-circuit voltage, and is mainly affected by internal resistance. The photoelectric conversion efficiency is calculated as a value obtained by dividing the maximum output (W) by ^{the light intensity (W) per 1 cm 2} and multiplying it by 100 to express it as a percentage. The photoelectric conversion element of the present invention can be applied to dye-sensitized solar cells or various light sensors. The dye-sensitized solar cell of the present invention is obtained by using a photoelectric conversion element containing a sensitizing dye for photoelectric conversion including the sensitizing dye represented by the above general formula (1) as a unit, and the unit is required The number of pieces is arranged for modularization, and specific electrical wiring is installed. [Examples] Hereinafter, the present invention will be specifically explained using examples, but the present invention is not limited to the following examples. Furthermore, in the synthesis examples, the identification of the compound was performed by ¹ H-NMR analysis (Nuclear Magnetic Resonance Device manufactured by JEOL Co., Ltd., JNM-ECA-600 or JNM-EX270). [Synthesis Example 1] The synthesis of sensitizing dye (A-5) was placed in a reaction vessel replaced by nitrogen, and 165 mL of toluene, 3,7-dibromodibenzothiophene 8.00 g, bis(4-third Octylphenyl)amine 10.12g, sodium-tertiary butoxide 3.37g, tris(dibenzylideneacetone)dipalladium(0)1.07g, and a concentration of 0.2 mg/mL of tri-tertiary butylphosphine/ 2.36 mL of toluene solution was stirred at 80°C for 2 hours. After the reaction liquid was cooled to 25°C, 380 mL of water and 380 mL of ethyl acetate were added and stirred, and the organic layer was extracted. The organic layer was washed with saturated brine, dried with sodium sulfate, and dried under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent (n-hexane)) and dried under reduced pressure to obtain a white solid (5.96) of the monobromide compound represented by the following formula (9) g). [化63]

Put 1.20 g of the monobromide represented by the above formula (9) and 16 mL of dehydrated tetrahydrofuran in a reaction vessel replaced by nitrogen, stir at -72℃, and add 1.6 M n-butyl group dropwise. After 1.5 mL of the lithium hexane solution, after reacting for 1 hour, 0.3 mL of dehydrated dimethylformaldehyde was added dropwise, and the reaction was performed for 2 hours. After that, the reaction liquid was put into ice water, and the organic layer was extracted with dichloromethane. The organic layer was washed with water, separated, dried with magnesium sulfate, and concentrated under reduced pressure. The residue was purified by chromatography (carrier: silica gel, solvent: hexane/toluene = 9/1 (volume ratio)) to obtain a white solid of the methylated compound represented by the following formula (10) ( 0.78 g). [化64]

In a reaction vessel replaced with nitrogen, 25 mL of acetic acid, 0.362 g of the formate compound represented by the above formula (10), 0.297 g of cyanoacetic acid, and 0.027 g of ammonium acetate were added, and the mixture was heated and stirred at 110° C. for 21 hours. After cooling the reaction liquid to 25°C, 125 mL of water was added and stirred, and the organic layer was extracted. The organic layer was washed sequentially with water and saturated brine, and the obtained organic layer was dried to obtain the target sensitizing pigment (0.333 g, yield 86%) in the form of a red solid. The obtained red solid was analyzed by NMR, the following 49 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-5) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (600 MHz, CDCl ₃ ): δ (ppm) = 0.66-0.88 (18 H), 1.24-1.40 (12 H), 1.60-1.80 (4 H), 6.95-7.10 (4 H), 7.14 -7.18 (1 H), 7.22-7.34 (4 H), 7.35-7.40 (1 H), 7.94-8.00 (1 H), 8.02-8.12 (2 H), 8.36-8.41 (1 H), 8.42-8.48 (1 H). [化65]

[Synthesis Example 2] The sensitizing dye (A-22) was synthesized in a reaction vessel replaced with nitrogen, and 10.7 mL of a mixture of acetic acid/toluene = 5/2 (volume ratio), obtained in Synthesis Example 1 0.247 g of the formylated compound represented by the formula (10) and 0.117 g of the indanone compound represented by the following formula (11) were stirred at 90°C for 3 hours. After the reaction liquid was cooled to 25°C, 50 mL of water was added and stirred, and the organic layer was extracted. The organic layer was washed sequentially with water and saturated brine, and dried to obtain the target sensitizing pigment (0.283 g, yield 93%) in the form of a reddish-brown solid. [化66]

The NMR analysis of the obtained reddish-brown solid was performed, the following 52 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-22) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (600 MHz, CDCl ₃ ): δ (ppm) = 0.64-0.85 (18 H), 1.22-1.45 (12 H), 1.70-1.91 (4 H), 6.95-7.00 (1 H), 7.01 -7.05 (4 H), 7.22-7.30 (1 H), 7.35-7.40 (4 H), 7.90-8.00 (1 H), 8.04-8.07 (1 H), 8.20-8.24 (1 H), 8.27-8.33 (1 H), 8.34-8.38 (1 H), 8.39-8.41 (1 H), 8.54-8.59 (1 H), 9.10-9.15 (1 H). [化67]

[Synthesis Example 3] Synthesis of sensitizing dye (A-28) In a reaction vessel replaced with nitrogen, 200 mL of toluene, 10.78 g of 3,7-dibromodibenzothiophene, and the following formula (12) were placed The indicated amine compound 5.27 g, sodium-tert-butoxide 4.54 g, tris(dibenzylideneacetone)dipalladium(0)1.44 g, concentration of 0.2 mg/mL tri-tert-butylphosphine/toluene solution 2.6 mL, stirred at 85°C for 2 hours. After the reaction liquid was cooled to 25°C, 150 mL of water and 500 mL of ethyl acetate were added and stirred, and the organic layer was extracted. The organic layer was washed with saturated brine, the obtained organic layer was dried with sodium sulfate, and concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent: n-hexane) and dried to obtain a white solid (5.32 g) of the monobromide compound represented by the following formula (13). [化68]

[化69]

Put 34.5 mL of N,N-dimethylformamide, 2.30 g of the monobromide compound of the above formula (13), and 1.01 g of phosphorous oxychloride into the reaction vessel replaced by nitrogen, and stir at 25°C for 90 Minutes, stirring at 60°C for 2 hours. The reaction liquid was put into 175 mL of ice water, and 175 mL of ethyl acetate was added to extract the organic layer. The extraction with ethyl acetate was carried out 3 times. The organic layer was dried with magnesium sulfate, and the solvent was distilled off, thereby obtaining a crude product. The obtained crude product was purified by column chromatography (carrier: silica gel, solvent: toluene) to obtain a brown solid of 2.25 g (91% yield) of the compound represented by the following formula (14). [化70]

Put 35 mL of N,N-dimethylformamide, 2.23 g of the compound represented by the above formula (14), 1.97 g of diethyl diphenylmethylphosphonate, and potassium 1.00 g of tributoxide was stirred at 25°C for 3 hours. After adding 90 mL of water to stop the reaction, the reactant was washed with water/methanol=1/1 (volume ratio). The obtained crude product was purified by column chromatography (carrier: silica gel, solvent: hexane/toluene = 5/1 (volume ratio)) to obtain the monobromination represented by the following formula (15) Body compound 2.89 g (yield 97%) as a yellow solid. [化71]

Put 0.500 g of the monobromide represented by the above formula (15) and 10 mL of dehydrated tetrahydrofuran in a reaction vessel replaced by nitrogen, stir at -72℃ and add 1.6 M n-butyl lithium dropwise. /Hexane solution 0.71 mL, react for 2 hours. After the reaction, 0.3 mL of dehydrated dimethylformaldehyde was added dropwise to the reaction solution and the reaction was carried out for 2 hours. Then, the reaction liquid was put into ice water, dichloromethane was added, and the organic layer was extracted. The organic layer was washed with water, separated, dried with magnesium sulfate, and concentrated under reduced pressure. The residue was purified by chromatography (carrier: silica gel, solvent: hexane/toluene = 9/1 (volume ratio)) to obtain a yellow solid of the methylated compound represented by the following formula (16) ( 0.196 g). [化72]

Put 8.5 mL of acetic acid/toluene=5/2 (volume ratio) mixed solution, 0.188 g of the methylated compound represented by the above formula (16), and the above formula (11) 0.102 g of the indanone compound was stirred at 90°C for 5 hours. After the reaction liquid was cooled to 25°C, 17 mL of methanol was added and stirred, and the reaction product was filtered. The reactant was washed with methanol, the obtained organic layer was dried, and the target sensitizing pigment (0.242 g, yield 98%) was obtained as a black solid. NMR analysis of the obtained black solid was performed, and the following 32 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-28) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (600 MHz, CDCl ₃ ): δ (ppm) = 1.25-1.28 (1 H), 1.47-1.49 (1 H), 1.55-1.60 (1 H), 1.72-1.76 (1 H), 1.80 -1.89 (1 H), 1.90-1.96 (3 H), 6.60-6.70 (1 H), 6.80-6.95 (1 H), 7.00-7.10 (2 H), 7.15-7.21 (2 H), 7.24-7.35 (5 H), 7.40-7.50 (4 H), 7.80-7.90 (1 H), 7.95-7.97 (1 H), 8.00-8.09 (1 H), 8.30-8.43 (4 H), 8.58-8.62 (1 H), 9.10-9.21 (1 H). [化73]

[Synthesis Example 4] Synthesis of sensitizing dye (A-32) In a reaction vessel replaced with nitrogen, 41 mL of toluene, 2.2 g of 3,7-dibromodibenzothiophene, and the following formula (17) were placed The indicated amine compound is 1.68 g, sodium-tert-butoxide 0.93 g, tris(dibenzylideneacetone)dipalladium(0) 0.29 g, concentration 0.2 mg/mL tri-tert-butylphosphine/toluene solution 0.37 mL, stirred at 80°C for 5 hours. After the reaction liquid was cooled to 25°C, 30 mL of water and 80 mL of ethyl acetate were added and stirred, and the organic layer was extracted. The organic layer was washed with saturated brine, dried with sodium sulfate, and concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, mixed solvent: n-hexane/toluene) and dried to obtain a white yellow solid of the monobromide compound represented by the following formula (18) ( 1.08 g). [化74]

[化75]

Put 1.00 g of the monobromide represented by the above formula (18) and 20 mL of dehydrated tetrahydrofuran into the reaction vessel replaced by nitrogen, stir at -72℃, and add 1.6M n-butyl group dropwise. 1.4 mL of lithium/hexane solution was reacted for 3 hours. After the reaction, 0.4 mL of dehydrated dimethylformaldehyde was added dropwise to the reaction solution and reacted for 2 hours. Then, the reaction liquid was put into ice water, dichloromethane was added, and the organic layer was extracted. The organic layer was washed with water, separated, dried with magnesium sulfate, and concentrated under reduced pressure. The residue was purified by chromatography (carrier: silica gel, solvent: hexane/toluene = 9/1 (volume ratio)) to obtain a yellow solid of the methylated compound represented by the following formula (19) ( 0.56 g). [化76]

In a reaction vessel replaced with nitrogen, 11 mL of acetic acid, 0.160 g of the formate compound represented by the above formula (19), 0.168 g of cyanoacetic acid, and 0.015 g of ammonium acetate were placed, and the mixture was stirred at 105°C for 7 hours. After cooling the reaction liquid to 25°C, 65 mL of water was added and stirred, and the organic layer was extracted. The organic layer was washed sequentially with water and saturated brine, and dried to obtain the target sensitizing pigment (0.155 g, yield 89%) in the form of a red solid. NMR analysis of the obtained red solid was performed, and the following 25 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-32) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (270 MHz, DMSO-d ₆ ): δ (ppm) = 1.90-2.06 (4 H), 2.30-2.40 (4 H), 3.90-4.00 (1 H), 4.90-5.10 (1 H), 7.29-7.60 (8 H), 7.89-8.00 (1 H), 8.10-8.22 (1 H), 8.30-8.50 (4 H), 8.51-8.65 (1 H). [化77]

[Synthesis Example 5] The sensitizing dye (A-33) was synthesized in a reaction vessel replaced by nitrogen, and 7.2 mL of a mixed solution of acetic acid/toluene=5/2 (volume ratio), represented by the above formula (19) 0.160 g of the formazan compound and 0.078 g of the indanone compound represented by the above formula (11) were stirred at 90°C for 6 hours. After the reaction liquid was cooled to 25°C, 15 mL of toluene was added and stirred, and the reactant was filtered. The reactant was washed with methanol and dried to obtain the target sensitizing pigment (0.133 g, yield 68%) in the form of a black solid. NMR analysis of the obtained black solid was carried out, the following 28 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-33) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (270 MHz, DMSO-d ₆ ): δ (ppm) = 1.39-1.41 (1 H), 1.64-1.67 (1 H), 1.83-1.92 (2 H), 2.00-2.11 (2 H) , 2.23-2.35 (3 H), 3.89-4.00 (1 H), 4.93-4.96 (1 H), 7.20-7.61 (8 H), 7.80-7.99 (2 H), 8.00-8.11 (1 H), 8.31 -8.43 (4 H), 8.50-8.63 (1 H), 9.18-9.21 (1 H). [化78]

[Synthesis Example 6] Synthesis of sensitizing dye (A-34) In a reaction vessel replaced with nitrogen, 100 mL of dimethyl sulfoxide, 2.86 g of the monobromide represented by the above formula (9), 5'-methanyl-2,2'-bithiophene-5-boronic acid 1.25 g, potassium carbonate 0.515 g, palladium(II) acetate 0.049 g, bis(1-adamantyl)-n-butylphosphine 0.157 g, Stir at 80°C for 3 hours. After the reaction liquid was cooled to 25°C, 460 mL of water and 460 mL of ethyl acetate were added and stirred, and the organic layer was extracted. The organic layer was washed with saturated brine, dried with sodium sulfate, and concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent: hexane/toluene = 1/2 (volume ratio)) and dried to obtain the formazanization represented by the following formula (20) The yellow-brown solid of the body compound (2.86 g). [化79]

Put 35 mL of acetic acid/toluene=5/2 (volume ratio) mixed solution, 0.770 g of the methylated compound represented by the above formula (20), and the above formula (11) 0.300 g of the indanone compound was stirred at 90°C for 7 hours. After cooling the reaction liquid to 25°C, the reaction liquid was concentrated under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent: chloroform/methanol = 5/2 (volume ratio)), and the target sensitizing pigment was obtained as a black solid (0.730 g, yield 78%). The obtained black solid was analyzed by NMR, the following 56 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-34) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (600 MHz, DMSO-d ₆ ): δ (ppm) = 1.00-1.04 (18 H), 1.59-1.63 (12 H), 1.93-2.02 (4 H), 7.25-7.37 (5 H) , 7.53-7.59 (4 H), 7.61-7.67 (2 H), 7.74-7.81 (2 H), 7.92-7.97 (1 H), 8.11-8.41 (6 H), 8.57-8.70 (2 H). [化80]

[Synthesis Example 7] Synthesis of sensitizing dye (A-35) In a reaction vessel replaced with nitrogen, 46 mL of dimethyl sulfoxide, 1.30 g of the monobromide represented by the above formula (13), 0.579 g of 5-methanyl-2-thiophene boronic acid, 0.364 g of potassium carbonate, 0.035 g of palladium (II) acetate, and 0.111 g of bis(1-adamantyl)-n-butylphosphine were stirred at 85°C for 2 hours. After the reaction liquid was cooled to 25°C, 200 mL of water and 200 mL of chloroform were added and stirred, and the organic layer was extracted. The organic layer was washed with saturated brine, dried with sodium sulfate, and dried under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent: hexane/toluene = 1/2 (volume ratio)) and dried to obtain the formazanization represented by the following formula (21) The yellow-brown solid of the body compound (1.33 g). [化81]

Put 20 mL of acetic acid/toluene = 1/3 (volume ratio) mixed solution, 0.270 g of the methylated compound represented by the above formula (21), and the above formula (11) in the reaction vessel replaced by nitrogen 0.193 g of the indanone compound was stirred at 90°C for 8 hours. After cooling the reaction liquid to 25°C, the reaction liquid was dried under reduced pressure to obtain a crude product. The crude product was purified by column chromatography (carrier: silica gel, solvent: chloroform/methanol = 5/1 (volume ratio)), and the target sensitizing pigment (0.280 g, yield) was obtained as a reddish-brown solid. Rate 75%). The NMR analysis of the obtained reddish-brown solid was performed, the following 24 hydrogen signals were detected, and it was identified as the structure represented by the following formula (A-35) (the hydrogen of the carboxyl group was not observed). ¹ H-NMR (600 MHz, DMSO-d ₆ ): δ (ppm) = 1.06-1.19 (1 H), 1.31-1.35 (1 H), 1.55-1.59 (1 H), 1.72-1.76 (1 H) , 1.91-2.02 (2 H), 3.78-3.82 (1 H), 4.78-4.82 (1 H), 6.69-6.73 (1 H), 7.00-7.12 (3 H), 7.37-7.41 (1 H), 7.75 -8.39 (11 H). [化82]

[Example 1] On a glass substrate coated with a fluorine-doped tin oxide thin film, a titanium oxide paste (manufactured by Nikkei Catalytic Chemicals Co., Ltd., PST-18NR) was coated by a doctor blade method. After drying at 110°C for 1 hour, it was fired at 450°C for 30 minutes to obtain a titanium oxide thin film with a thickness of 7 μm. Then, the sensitizing dye (A-5) and deoxycholic acid obtained in Synthesis Example 1 were dissolved in acetonitrile/tert-butanol=1/1 (volume ratio ) In a mixed solvent, and prepare 50 mL of a solution. In this solution, the glass substrate coated with sintered titanium oxide is immersed at room temperature for 15 hours, and the above-mentioned sensitizing dye is adsorbed as a sensitizing dye for photoelectric conversion. Make a photoelectrode. On a glass substrate coated with a fluorine-doped tin oxide film, a platinum film with a thickness of 15 nm was formed by using an automatic fine coating machine (JFC-1600 manufactured by JEOL Co., Ltd.) by sputtering. Opposite electrode. Then, a spacer (hot-melt film) with a thickness of 60 μm between the photoelectrode and the counter electrode is bonded by heat fusion, and after the electrolyte is injected into the hole formed in the counter electrode in advance, the hole is sealed, and Fabrication of photoelectric conversion elements. As the electrolyte, a 3-methoxypropionitrile solution of 0.1 M lithium iodide, 0.6 M dimethylpropylimidazolium iodide, 0.05 M iodine, and 0.5 M 4-tert-butylpyridine was used. From the photoelectrode side of the above-mentioned photoelectric conversion element, irradiate the light generated by the simulated sunlight irradiation device (OTENTO-SUN III type manufactured by Bunkoukeiki Co., Ltd.), and measure the current using a power meter (made by KEITHLEY, Model 2400 General-Purpose SourceMeter) -Voltage characteristics. The light intensity is adjusted to 100 mW/cm ² . In addition, the photoelectric conversion efficiency was also measured after being irradiated with light for 20 hours, and the characteristic change was evaluated. Table 1 summarizes the measurement results. [Example 2 to Example 9] As the sensitizing dye for photoelectric conversion, except that the sensitizing dye shown in Table 1 was used instead of (A-5), a photoelectric conversion element was produced in the same manner as in Example 1, and measured Current-voltage characteristics. In addition, the photoelectric conversion efficiency was also measured after being irradiated with light for 20 hours, and the characteristic change was evaluated. Table 1 summarizes the measurement results. [Comparative Example 1 to Comparative Example 4] As a sensitizing dye for photoelectric conversion, the following formulas (B-1) to (B-4), which are not part of the present invention and disclosed in the prior art (Patent Documents 4 to 6), were used Except that the sensitizing dye shown was substituted for (A-5), a photoelectric conversion element was produced in the same manner as in Example 1, and the current-voltage characteristics were measured. In addition, the photoelectric conversion efficiency was also measured after being irradiated with light for 20 hours, and the characteristic change was evaluated. Table 1 summarizes the measurement results. [化83]

[化84]

[化85]

[化86]

[Table 1]

According to the results of Table 1, it is found that by using the sensitizing dye for photoelectric conversion containing the sensitizing dye of the present invention, high photoelectric conversion efficiency can be obtained and high photoelectric conversion can be maintained even if light irradiation is continued for a long time. High efficiency photoelectric conversion element. On the other hand, the photoelectric conversion efficiency of the photoelectric conversion element using the sensitizing dye for photoelectric conversion of the comparative example was insufficient. The present invention has been described in detail with reference to specific aspects, but the industry should understand that various changes and modifications can be made without departing from the spirit and scope of the present invention. In addition, this application is based on a Japanese patent application (Japanese Patent Application No. 2016-188633) filed on September 27, 2016, and the entire content is incorporated by reference. In addition, all reference systems cited here are incorporated herein as a whole. [Industrial Applicability] The sensitizing dye for photoelectric conversion containing the sensitizing dye of the present invention is useful as a high-efficiency and high-durability photoelectric conversion element and dye-sensitized solar cell. Solar cells convert the ground into electricity to provide clean energy.

1‧‧‧Conductive support 2‧‧‧Pigment-supported semiconductor layer 3‧‧‧Electrolyte layer 4.‧‧Counter electrode 5‧‧‧Conductive support

FIG. 1 is a schematic cross-sectional view showing the structure of the photoelectric conversion element of the embodiment of the present invention and the comparative example.

Claims (6)

A sensitizing pigment represented by the following general formula (1),

[In the formula, R ¹ to R ⁶ may be the same or different, and each independently represents a hydrogen atom, a halogen atom, a linear or branched alkyl group with 1 to 6 carbon atoms, or a 1 to 6 carbon atom The linear or branched alkoxy group; R ⁷ and R ⁸ may be the same or different, and represent a linear or branched alkoxy group with 1 to 19 carbon atoms, which may also have a halogen atom, An aryl group having 6 to 19 carbon atoms, a disubstituted amino group having a substituent selected from a linear or branched alkyl group having 1 to 18 carbon atoms or an aryl group having 6 to 18 carbon atoms, Hydroxyl group, carboxyl group, carboxylate group, or cyano group is a linear or branched alkyl group with 1 to 20 carbon atoms as a substituent, and it may also have a halogen atom and a linear chain with 1 to 17 carbon atoms. Or branched alkyl, linear or branched alkoxy with 1 to 17 carbon atoms, aryl with 6 to 17 carbon atoms, linear with 1 to 16 carbon atoms Or a branched alkyl group or a bi-substituted amino group, a hydroxy group, a carboxyl group, a carboxylate group, a vinyl group, or a cyano group as a substituent in the aryl group with 6 to 16 carbon atoms. The carbon number of the substituent is 3 ~20 cycloalkyl groups, may also have halogen atoms, straight-chain or branched alkoxy groups with 1 to 18 carbon atoms, aryl groups with 6 to 18 carbon atoms, and have selected from 1 to The disubstituted amino group, hydroxyl group, carboxyl group, carboxylate group, or cyano group as the carbon atom of the substituent in the 17 linear or branched alkyl group or the aryl group with 6 to 17 carbon atoms Linear or branched alkenyl with 2 to 20, halogen atoms, linear or branched alkyl with 1 to 19 carbon atoms, and linear with 1 to 19 carbon atoms Or a branched alkoxy group, a disubstituted amino group and a hydroxyl group having a substituent selected from a linear or branched alkyl group with 1 to 18 carbon atoms or an aryl group with 6 to 19 carbon atoms , Carboxyl group, carboxylate group, vinyl group, or cyano group as a substituent C7~26 aralkyl group, or halogen atom, linear or branched chain with 1~24 carbon atoms The alkyl group, the linear or branched alkoxy group with 1 to 24 carbon atoms, the aryl group with 6 to 24 carbon atoms, the linear or branched chain with 1 to 23 carbon atoms Alkyl group or aryl group with 6 to 23 carbon atoms is a disubstituted amino group, hydroxyl group, carboxyl group, carboxylate group, vinyl group, or cyano group as a substituent in an aryl group with 6 to 30 carbon atoms. Group, R ⁷ and R ⁸ may also be bonded to each other to form a ring; X represents a monovalent group represented by the following general formula (X1), (X2) or (X3),

[In the formula, R ⁹ represents an acidic group]

[In the formula, L and M may be the same or different, which means having one selected from carboxyl group, sulfonic acid group, phosphoric acid group, hydroxamic acid group, phosphonic acid group, boric acid group, phosphinic acid group or silanol group or Two acidic groups as substituents have a linear or branched alkyl group with 1 to 6 carbon atoms, or an unsubstituted linear or branched alkyl group with 1 to 6 carbon atoms; , At least any one of L or M has one or two acidic groups selected from carboxyl group, sulfonic acid group, phosphoric acid group, hydroxamic acid group, phosphonic acid group, boric acid group, phosphinic acid group or silanol group As a substituent, a linear or branched alkyl group having 1 to 6 carbon atoms; p represents an integer of 0 to 2, and when p is 2, multiple Ls may be the same or different from each other]

[In the formula, R ¹¹ and R ¹² represent a hydrogen atom or an acidic group, at least one of R ¹¹ or R ¹² is an acidic group; R ¹³ and R ¹⁴ may be the same or different, and represent a hydrogen atom or a halogen atom , Cyano, hydroxyl, nitro, nitroso, thiol, cycloalkyl with 3 to 16 carbon atoms, straight-chain alkoxy with 1 to 16 carbon atoms, with 3 to 16 carbon atoms Branched alkoxy group, cycloalkoxy group with 3 to 16 carbon atoms, aryl group with 6 to 16 carbon atoms, unsubstituted amine group, amine group with substituents with 1 to 16 carbon atoms , Carboxyl group, or carboxylate group as a substituent, a linear or branched alkyl group with 1 to 18 carbon atoms, which may also have a halogen atom, a cyano group, a hydroxyl group, a nitro group, a nitroso group, and a mercaptan Group, cycloalkyl group with 3 to 16 carbon atoms, linear alkoxy group with 1 to 16 carbon atoms, branched chain alkoxy group with 3 to 16 carbon atoms, with 3 to 16 carbon atoms Cycloalkoxy, aryl groups with 6 to 16 carbon atoms, unsubstituted amine groups, amine groups with 1 to 16 carbon atoms, carboxyl groups, or carboxylate groups as substituent carbon atoms 1 to 18 linear or branched alkoxy groups, or halogen atoms, cyano groups, hydroxyl groups, nitro groups, nitroso groups, thiol groups, cycloalkyl groups with 3 to 16 carbon atoms, Straight-chain alkoxy with 1-16 carbon atoms, branched alkoxy with 3-16 carbon atoms, cycloalkoxy with 3-16 carbon atoms, aromatic with 6-16 carbon atoms Group, unsubstituted amine group, amine group, carboxyl group, or carboxylate group having substituents with 1 to 16 carbon atoms as the substituents linear or branched alkenes with 2 to 18 carbon atoms R ¹³ and R ¹⁴ can also be bonded to each other to form a ring; r represents an integer from 0 to 4, and when r is an integer from 2 to 4, R ¹³ and R ¹⁴ that exist in plural are R ¹³ Each other and R ¹⁴ may be the same or different from each other]]. The sensitizing dye of claim 1, wherein in the above general formula (1), all of R ¹ to R ⁶ are hydrogen atoms. Such as the sensitizing dye of claim 2, wherein in the above general formula (1), R ⁷ and R ⁸ are a linear or branched alkyl group having 1 to 17 carbon atoms, carbon A linear or branched alkoxy group with 1 to 17 atoms, an aryl group with 6 to 17 carbon atoms, a linear or branched alkyl group or carbon with 1 to 16 carbon atoms A di-substituted amino group, a hydroxyl group, a carboxyl group, a carboxylate group, a vinyl group, or a cyano group as a substituent in an aryl group with 6 to 16 atoms is a cycloalkyl group with 3 to 20 carbon atoms, or also May have halogen atoms, linear or branched alkyl groups with 1 to 24 carbon atoms, linear or branched alkoxy groups with 1 to 24 carbon atoms, aromatics with 6 to 24 carbon atoms Groups, disubstituted amino groups, hydroxyl groups, carboxyl groups, and carboxylate groups with substituents selected from linear or branched alkyl groups with 1 to 23 carbon atoms or aryl groups with 6 to 23 carbon atoms ^{R 7} and R ⁸ may be bonded to each other to form any of the aryl groups having 6 to 30 carbon atoms as a substituent, a vinyl group, or a cyano group. A sensitizing dye for photoelectric conversion, which comprises the sensitizing dye according to any one of claims 1 to 3. A photoelectric conversion element using the sensitizing dye for photoelectric conversion as in claim 4. A dye-sensitized solar cell using the photoelectric conversion element of claim 5.

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