JP5598918B2 - Detection of rare earth metals using calixarene derivatives - Google Patents

Description

  According to the present invention, a novel calixarene derivative is obtained, and this derivative is used to react with a lanthanoid series rare earth metal, particularly dyspronium, in response to a change in the concentration of the lanthanoid series rare earth metal, especially dyspronium. The present invention relates to a method for highly selectively sensing a lanthanoid series rare earth metal, particularly dyspronium, by utilizing the change of the maximum spectral wavelength.

  Calixarene is a general term for cyclic oligomers in which a plurality of phenols having an alkyl group are bonded via the methylene group at the 2,6-positions. The number of phenols constituting the ring [n] is represented as calix (n) arene. Various attempts have been made focusing on the structure of calixarene.

The present inventor has eagerly made efforts to create and use a supramolecule, which is a so-called soft material, having a group of molecules as one chemical species. Of these, we focused on calixarene.
Calixarene has an inclusion function and a cation trapping function depending on its structure. This property is to be used.
Since 1987, the present inventors have synthesized a calixarene, which is a cyclic oligomer by the condensation of phenol and formaldehyde, in advance as a state in which an atomic and molecular recognition element based on this is prepared, and synthesized this. Using this, we succeeded in recognizing atoms and molecules. For example, by changing the number of phenols to 4, 6 and 8, the calix [n] arene derivative has selectivity for alkali metal ions (Non-patent Document 4), and calix [6 It was found that the arene derivatives function as “super uranium ligands” exhibiting great selectivity for uranyl ions, and their use was clarified (Non-patent Document 5). In addition, a novel compound, 5-formyl-17-nitro-25,27-dipropoxy-26,28-bis (benzyloxy) calix [4] arene, was synthesized, and an electron-donating group and an electron-withdrawing group were synthesized. The invention has an electron transfer element having a molecular recognition ability as a derivative of a calix [4] arene compound by having these groups at positions of 1,3 alternations (Patent Document 8). ).
In the field of calixarene, many researchers are making efforts and producing interesting results. For example, as a fluorescence detection reagent for immunoassay (immunoassay), a ligand derivative having four carboxylic acids (Patent Documents 1 and 2), a ligand having an amide bond and an amine moiety (Patent Document 3), pyridine There are reports of ligands in which rings are bridged (Patent Document 4) and ligands containing 2 or 4 β-diketone structures (Patent Document 5). The target metal is mainly europium because the energy transfer from the ligand to the lanthanoid metal ion is performed efficiently and the fluorescence amplification of the metal ion is intended for research. Calixarene has an inclusion function, a cation capturing function, and the like, and is applied as a metal removal, a sensor compound, a certain kind of clinical test reagent, and the like (Patent Document 7).
Molecular and atomic recognition using calixarene will continue to be studied and put to practical use.

Currently, rare earth metals include structural materials such as stainless steel, heat-resistant materials, special steels, semiconductor / laser, fuel cells, permanent magnets, magnetic recording elements and other electronic / magnetic materials, photocatalysts, optical glass, transparent electrodes, hydrogen storage alloys. It is widely used for functional materials. Its importance has been pointed out in various fields. The rare earth metal group is a raw material for high-value-added members that support the Japanese industrial field, and its demand has been increasing in recent years. This trend is expected to continue.
Among the rare earth metal group, the rare earth metal group called lanthanoid series includes dyspronium, which is essential for the drive motor of hybrid vehicles, cerium, which is a glass disk abrasive in panel hard disks and hard disks for PCs, and fluorescence for liquid crystal backlights. There are europium essential for the body. Since the physical and chemical properties of the lanthanoid series elements are similar to each other, each abundance is detected in the state of resource stones and in the state of coexistence in the high-end member that is the product finally recovered after use, It is difficult to separate and take out as necessary. Under this circumstance, the most needed technology is advanced sensing technology and needs to be established as soon as possible.

However, these sensing technologies are currently left unsolved. Most of the inventions that use ligands of conventional lanthanoid series metal groups are inventions related to molecular design for use as a medical fluorescent probe. A typical example is as follows.
A metal complex is disclosed in which rare metals are coordinated to ethylenediaminetetracomplex acid and 5-formylsalicylic acid to produce three primary colors (Patent Document 6). This is a study on fluorescent color screening of metal complexes.
The calix [8] arene derivative, which is a host compound that shows selectivity for alkali metal ions, is europium (non-patent paper 1) and lanthanoid binuclear metals (europium neodymium, terbium neodymium, europium terbium) (non-patent paper 2). ) Has been reported to meet.
They study optical properties such as changes in fluorescence intensity due to energy transfer. In addition, β and γ cyclodextrin derivatives have been reported to form complexes with praseodymium at an association constant (log Ka) of 3.5 to 4.0. In these studies, the series of ligands of the above lanthanoid series metal group has been molecularly designed to amplify the fluorescence intensity of complexed lanthanoid series elements. The main aim of the research is coordination The main point of research is how much energy can be transferred from the child to the lanthanoid metal.
We have to say that the technology that we currently require is to detect each abundance in a coexisting state and to separate and extract it as necessary.

The lanthanoid group elements have a significant increase in demand in developing countries, and the metals themselves are scarce and have very low substitutability compared to other metals in the first place. Paying attention to the high price, the question has been whether Japan can secure a stable supply over the medium to long term. As a result, as specific measures, the “strategies for securing a stable supply of nonferrous metal resources” reported by the Agency for Natural Resources and Energy in June 2006 included (1) Promotion of exploration and development, (2) Alternative materials Solution methods are organized based on the development issues and specific measures are currently underway.
Even in this, lanthanoid series metal group sensing technology is considered important for recovery, but no specific measures have been provided and preparations have not been made.
In any case, the invention related to the design and use of a ligand that selectively senses lanthanoid metal ions of the lanthanoid series metal group is the most important theme, and the next step is to separate it. It is an important fundamental theme for making this possible.

JP 2003-254958 A Special table 2010-501481 gazette JP 2009-215238 A Special table 2004-509075 gazette JP 2000-111480 A JP 2009-292748 A JP 2009-184996 A Japanese Patent No. 3882029

Chemical Reviews, 1998, 98, 2495-2525. Inorganic Chemistry, 1993, 32, 3306-311. Carbohydrate Research, 2005, 340, 131-138. Bull. Chem. Soc. Jpn. 1989, 62, 1674-1676. J. et al. Am. Chem. Soc. 1987, 109, 6371-6376.

  The problem to be solved by the invention is to overcome the resource constraints and to be a new means for sensing specific lanthanoid series elements that play an important role in the high-end materials industry from the viewpoint of building a recycling-type economic system. The object is to provide a novel sensing method using the material and the material.

This inventor examined the material which can detect a specific lanthanoid series metal, and its utilization method. The present inventors have found that the problem to be solved by the invention can be solved by confirming the following two things.
(1) Invention of a novel material that can be used as a means for sensing a specific lanthanoid series element We believe that lanthanoid series metals can be separated by substances obtained by chemically modifying calixarene as a base. It was.
From a ligand in which a propyl group is bonded to two opposing hydroxyl groups of calix [4] arene to control the size of the cleft, and a single molecule of boron dipyrromethene phosphor is chemically modified at the para position of phenol. The novel compound, boron dipyrromethene-calix [4] arene (1), was produced by paying attention to the cleft formed by the four hydroxyl groups of calix [4] arene.
(2) Invention of novel material and novel sensing method using the material (a) Step 1 MX containing a predetermined amount of lanthanoid series rare earth metal in a solution of boron dipyrromethene-calix [4] arene (1) ₃ (M represents a lanthanoid series rare earth metal, X represents an acetylacetonate group) and the absorption spectrum of boron dipyrromethene-calix [4] arene (1) has a maximum value through the isoabsorption point. Step of observing that the absorption spectrum changes after migration The absorption spectrum was measured for dyspronium ions (FIG. 2).
(B) Step 2 From the figure created in Step 1, the association constant is calculated from this spectrum change.
Indicating that the dyspronium ion is associated and the aggregate stoichiometry is 1: 1,
The association constant was calculated to be K = 5.4 × 10 ⁷ .
Similarly, association constants of other predetermined amounts of lanthanoid series rare earth metals are calculated.
(C) Step 3 Which rare earth metal of the lanthanoid series rare earth metal corresponds to the measurement object is determined, and the concentration of the rare earth metal is determined from the association constant.

  When the boron dipyrromethene-calix [4] arene (1) which is a calix [4] arene derivative obtained by the present invention is used, a lanthanoid series metal can be sensed. It shows high selectivity for lanthanoid series metals used for high-end members, especially dyspronium. Thereby, detection of dyspronium can be performed. In Japan, where rare earth metal resources are scarce, it is possible to sense rare earth metals in discarded high-end components and cooperate with support measures for recycling operations, contributing to the construction of a recycling-type economic system that overcomes resource constraints.

The comparative compound, 5- (4-hydroxyphenyl) -boron dipyrromethene (4), has a maximum absorption (λmax) at 505 nm at a concentration of 1.0 × 10 ⁻⁵ M in dimethylformamide (DMF) at 25 ° C. The absorption spectrum which has is shown. Even if a metal salt of lanthanoid metal (MX ₃ , X is an acetylacetonato (acac) functional group) coexists in this solution (˜3.0 × 10 ⁻⁴ M), the absorption spectrum of compound (4) is It is a figure which shows that it did not change at all, and the sensing interaction with a lanthanoid metal was not detected. The concentration of Dy (acac) ₃ is 2.0 × 10 ⁻⁶ M at 25 ° C. with respect to a DMF solution of boron dipyrromethene-calix [4] arene (1) having a concentration of 1.0 × 10 ⁻⁵ M. 4.0 × 10 ⁻⁶ M, 6.0 × 10 ⁻⁶ M, 8.0 × 10 ⁻⁶ M, 1.0 × 10 ⁻⁵ M, 2.0 × 10 ⁻⁵ M Adjusted and added. The absorption spectrum of boron dipyrromethene-calix [4] arene (1)) shows that the maximum wavelength has changed through the isosbestic point.

  The method for detecting a lanthanoid series metal according to the present invention comprises a method for designing a compound having a ligand by an appropriate chemical modification of calix [4] arene and a method for sensing a lanthanoid series metal using this ligand.

Boron dipyrromethene-calix [4] arene (1), which is a compound for detecting the lanthanoid series metal ligand of the present invention, is a novel compound represented by the following structural formula (1).

  The boron dipyrromethene-calix [4] arene (1) controls the size of the cleft by binding a propyl group to two opposing hydroxyl groups of the calix [4] arene, and further emits a single molecule of boron dipyrromethene. It is a novel compound consisting of a ligand whose body is chemically modified to the para position of phenol. This structure reacts with a lanthanoid series rare earth metal. The lanthanoid metals are yttrium (Yb), dyspronium (Dy), terbium (Tb), gadolinium (Gd), europium (Eu), samarium (Sm), cerium (Ce), and lanthanum (La). In particular, dyspronium (Dy) is likely to react.

The boron dipyrromethene-calix [4] arene (1) is produced from the following two steps.
Manufacturing process 1
Synthesis method of dipyrromethane derivative A dipyrromethane derivative is produced from pyrrole and monoformylcalixarene. Specifically, it is as follows.
Dissolve monoformylcalixarene (Structural Formula 2) in pyrrole, add a few drops of trifluoroacetic acid in an argon atmosphere and shield from light, and stir. After completion of the reaction, methylene chloride is added and washed with aqueous sodium hydroxide solution and then with water. After the solvent is distilled off under reduced pressure, purification is performed by column chromatography to obtain a dipyrromethane derivative (Structural Formula 3).

Manufacturing process 2
The desired boron dipyrromethene-calix [4] arene (1) is produced from the dipyrromethane derivative and trifluoroboric acid diethyl ether complex (DDQ). Specifically, it is as follows.
Monodipyromethane-calix [4] arene (Structural Formula 3) is dissolved in dry toluene, and trifluoroboric acid diethyl ether complex (DDQ) is added and stirred. Triethylamine and trifluoroboric acid diethyl ether complex were added, and the mixture was further stirred for 45 minutes. Methylene chloride was added to the reaction mixture, and the organic layer was washed twice with water. After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and purification was performed by column chromatography (silica gel, methylene chloride). Furthermore, after dissolving in chloroform and reprecipitating by adding hexane, washing with methanol is performed to obtain boron dipyrromethene-calix [4] arene (1) (Structural Formula 1) as an orange powder.

Manufacturing steps 1 and 2 are as follows.

Sensing of the lanthanoid metal (M) using boron dipyrromethene-calix [4] arene (1) is as follows.
The lanthanoid metal (M) to be sensed is as follows. Yttrium (Yb), dyspronium (Dy), terbium (Tb), gadolinium (Gd), europium (Eu), samarium (Sm), cerium (Ce), and lanthanum (La).
Among them, dyspronium (Dy) can be most satisfactorily sensed.

The absorption spectrum of the lanthanoid metal (M), which varies depending on the addition amount, using boron dipyrromethene-calix [4] arene (1) is measured as follows.
The contents are shown in FIG.
(1) For boron dipyrromethene-calix [4] arene (1), when the concentration of Dy (acac) ₃ is 0 in dimethylformamide (DMF) at 25 ° C., the absorption spectrum of the maximum absorption (λmax) The peak is measured at 500 nm. In this case, no other peak is measured.
(2) Next, when the concentration of Dy (acac) ₃ is 2.0 × 10 ⁻⁶ M, the peak of the absorption spectrum of the maximum absorption (λmax) at 500 nm starts to decrease, and then The following absorption spectrum is formed around 490 nm. An isosbestic point is interposed between the peaks. A peak is observed near 600 nm. Also in this case, an isosbestic point is interposed between the peaks.
(3) In the case where the concentration of Dy (acac) ₃ is 4.0 × 10 ⁻⁶ M, the peak of the absorption spectrum of the maximum absorption (λmax) at 500 nm is further lowered, and then it is around 490 nm. The following absorption spectrum formation is observed. At this stage, the peak of the absorption spectrum of the maximum absorption (λmax) at 500 nm further decreases, and then the peak near 490 nm increases, and almost the same absorption spectrum is formed. An isosbestic point is interposed between the peaks. The peak near 600 nm also increases.
(4) In the case where the concentration of Dy (acac) ₃ is 6.0 × 10 ⁻⁶ M, the peak of the absorption spectrum of the maximum absorption (λmax) at 500 nm is further lowered, and next, it is around 490 nm. The following absorption spectrum formation is observed. At this stage, the peak of the absorption spectrum at 500 nm further decreases, then the peak near 490 nm further increases, and then the absorption spectrum of the peak near 490 nm becomes the absorption spectrum of the maximum absorption (λmax). An isosbestic point is interposed between the peaks. In addition, the peak near 600 nm is further increased.
(5) As the concentration of Dy (acac) ₃ changes to 8.0 × 10 ⁻⁶ M, 1.0 × 10 ⁻⁵ M, and 2.0 × 10 ⁻⁵ M, the conventional tendency becomes more prominent. Eventually, the absorption spectrum at 500 nm disappears, and the maximum absorption (λmax) increases remarkably in the absorption spectrum of the peak near 490 nm. An isosbestic point is interposed between the peaks. Although the peak near 600 nm further increases, the absorption spectrum of the peak near 490 nm does not exceed the maximum absorption (λmax).

  The sensing process is performed by the following processes 1 to 3.

a Step 1
To a solution of boron dipyrromethene-calix [4] arene (1), MX ₃ containing a predetermined amount of a lanthanoid series rare earth metal (M represents a lanthanoid series rare earth metal, X represents an acetylacetonate group) is added. The step of measuring the change in the absorption spectrum of the absorption spectrum of boron dipyrromethene-calix [4] arene (1) through which the maximum value passes through the isoabsorption point.
In a solution of boron dipyrromethene-calix [4] arene (1), the concentration of a metal salt of a lanthanoid metal (MX ₃ , M represents a lanthanoid metal, X represents acetylacetonate (acac)) is changed. (For example, as described above, at 25 ° C., the concentration of Dy (acac) ₃ is 2.0 × 10 ⁻⁶ M, 4.0 × 10 ⁻⁶ M, 6.0 × 10 ⁻⁶ M, 8. 0 × 10 ⁻⁶ M, 1.0 × 10 ⁻⁵ M, 2.0 × 10 ⁻⁵ M), and the metal salt of the lanthanoid metal ((MX ₃ , M is a lanthanoid metal) X represents acetylacetonate (acac))) and boron dipyrromethene-calix [4] arene (1), and the absorption spectrum of boron dipyrromethene-calix [4] arene (1) is Isospiration Can be observed that the changes through the point (Fig. 2).
The specific contents are as described above.

ボロンジピロメテン−カリックス［４］アレーン（１）とランタノイド系金属群との会合定数の算出方法の手順を示すと以下のとおりである。
会合定数は、ボロンジピロメテン−カリックスアレーン（１）（＝[Ａ]）の吸収スペクトルが、共存金属イオン（＝[Ｂ]）の濃度を変化させることにより等吸収点を通って変化することから下式より求めた。

式中、OD_0、DO_comp、及びODは以下のとおりである。
OD₀：ボロンジピロメテンーカリックスアレーン（１）の初期の吸光度
DO_comp：飽和した時の吸光度
OD：共存金属イオンを濃度変化させたときの吸光度

図２の場合の会合定数は、Ｋ＝５．４×１０^７であると算出した。吸収スペクトル測定には、株式会社島津製作所製、ＵＶ−３１０１ＰＣを使用できる。
同様にしてボロンジピロメテン−カリックス［４］アレーン（１）とランタノイド系金属群との会合定数の算出結果を以下の表１にまとめた。

b Step 2
Observing the table of FIG. 2 indicates that boron dipyrromethene-calix [4] arene (1)) and dyspronium ions are associated with a stoichiometric ratio of 1: 1. Wow. The association constant is calculated based on this spectral change.
The association constant is as follows.
In this reaction formula, the association constant Ka is _a value determined by the following formula.

The procedure for calculating the association constant between the boron dipyrromethene-calix [4] arene (1) and the lanthanoid metal group is as follows.
The association constant is that the absorption spectrum of boron dipyrromethene-calixarene (1) (= [A]) changes through the isoabsorption point by changing the concentration of the coexisting metal ion (= [B]). Obtained from the following equation.

In the formula, OD _0, DO _comp , and OD are as follows.
OD ₀ : initial absorbance of boron dipyrromethene calixarene (1)
DO _comp : Absorbance when saturated
OD: Absorbance when the concentration of coexisting metal ions is changed

The association constant in the case of FIG. 2 was calculated to be K = 5.4 × 10 ⁷ . For the absorption spectrum measurement, UV-3101PC manufactured by Shimadzu Corporation can be used.
Similarly, calculation results of association constants of boron dipyrromethene-calix [4] arene (1) and the lanthanoid metal group are summarized in Table 1 below.

c Step 3
The absorption constant is measured according to the concentration change of the unknown sample to be measured, and the association constant to be measured is calculated.
In addition, Dy (Dyspronium) shown in Table 1 shows high selectivity.

The lanthanoid rare metal in the discarded high-end member can be used as it is when it is in a metal salt (MX ₃ ) (X represents acetylacetonate) state during sensing. When it is not in this state, it is necessary to be in an acetonate state in advance. Rare metal complexation is possible by adding an alcohol solution of acetylacetone, a DMF solution, or an acetone solution under weakly basic conditions.

  Hereinafter, the present invention will be described in detail with reference to examples. The present invention is not limited to this.

Method for synthesizing dipyrromethane derivative (3) Monoformylcalixarene (1.6 g, 2.5 mmol) was dissolved in 15 g (0.22 mmol) of pyrrole, and several drops of trifluoroacetic acid were added in an argon atmosphere and protected from light, followed by stirring for 30 minutes. After completion of the reaction, 100 ml of methylene chloride was added and washed with an aqueous sodium hydroxide solution and then with pure water. After the solvent was distilled off under reduced pressure, purification was performed by column chromatography (Silicagel CH ₂ Cl ₂ : CH ₃ CO ₂ Et: Et ₃ N = 90: 10: 1) to obtain a dipyrromethane derivative (the above structural formula 3) (1. 8 g, 92%).

The physical properties of the dipyrromethane derivative are as follows.
mp: 140-142 ° C
¹ H-NMR (CDCl ₃ ) d 1.32 (6H, t, J = 7.4 Hz, OCH ₂ CH ₂ CH ₃ ), 2.03-2.11 (4H, m, OCH ₂ CH ₂ CH ₃ ), 3.31, 3.35, 4.28, 4.33 (each 2H, d, J = 12.9 Hz, Ar—CH ₂ —Ar), 3.97 (4H, t, J = 6.3 Hz, OCH _{2 CH 2 CH 3), 5.35 (} 1H, s, Ar-CH- (pyrrole) 2), 5.95 (2H, bs, pyrrole-H), 6.16 (2H, m, Ar), 6. 25 (2H, d, J = 1.6 Hz, pyrole-H), 6.65 (2H, d, J = 1.3 Hz, pyrole-H), 6.77 (1H, t, J = 7.4 Hz, Ar), 6.79-6.82 (2H, m, Ar), 6.86 (2H, d, J = .7 Hz, Ar), 6.87 (2H, s, Ar), 6.96, 7.07 (each 2H, d, J = 7.4 Hz, Ar) 7.84 (2H, bs, pyrolele-NH), 8.46, 8.49 (each1H, s, OH)
massspectrum (FAB) m / z 652 (M ⁺ )
_{elemental analysis, calcs for C 43 H} 44 N 2 O 4 · 1 / 3H 2 O: C, 78.39%; H, 6.83%; N, 4.25%.
Found: C, 78.54%; H, 6.83%; N, 3.96%.

Method for synthesizing boron dipyrromethene-calix [4] arene (1) A dipyrromethane derivative (formula 3 above) (1.1 g, 1.7 mmol) is dissolved in dry toluene, and trifluoroboric acid diethyl ether complex (DDQ ) 0.40 g (1.7 mmol) was added and stirred for 20 minutes. 1.7 mL (12 mmol) of triethylamine and 1.5 mL (12 mmol) of trifluoroboric acid diethyl ether complex were added, and the mixture was further stirred for 45 minutes. Methylene chloride was added to the reaction mixture, and the organic layer was washed twice with water. After drying over anhydrous sodium sulfate, the solvent was distilled off under reduced pressure, and purification was performed by column chromatography (silica gel, methylene chloride). Furthermore, after dissolving in chloroform and reprecipitating by adding hexane, washing with methanol was performed to obtain boron dipyrromethene-calix [4] arene (1) (structural formula (1)) as an orange powder. Obtained .45 g (43%).

Physical properties of boron dipyrromethene-calix [4] arene (1) mp: 290 ° C. (decomp.)
¹ H-NMR (CDCl ₃ ) d 1.36 (6H, t, J = 7.4 Hz, OCH ₂ CH ₂ CH ₃ ), 2.08-2.15 (4H, m, OCH ₂ CH ₂ CH ₃ ), 3.42, 3.47, 4.34, 4.39 (each 2H, d, J = 12.9, 13.2 Hz, Ar—CH ₂ —Ar), 4.01, 4.02 (each 2H, t, J = 6.2 Hz, OCH ₂ CH ₂ CH ₃ ), 6.55 (2H, d, J = 1.7 Hz, pyrrole-H), 6.66 (1H, t, J = 7.4 Hz, Ar), 6.85 (2H, d, J = 7.5 Hz, Ar), 6.96-7.03 (6H, m, polarle-H, Ar), 7.08 (2H, d, J = 7.4 Hz, Ar), 7.35 (2H, s, Ar), 7.90 (2H, bs, pyrolele-H), 8. 8,9.19 (each1H, s, OH)
mass spectrum (FAB) m / z 698 (M ⁺ )
_{elemental analysis, calcsforC 43 H 41 BF} 2 N 2 O 4: C, 73.93%; H, 5.92%; N, 4.01%.
Found: C, 74.15%; H, 5.83%; N, 3.68%.

About boron dipyrromethene-calix [4] arene (1), the state which shows sensing with respect to a dyspronium ion is as follows.
In a DMF solution of boron dipyrromethene-calix [4] arene (1) having a concentration of 1.0 × 10 ⁻⁵ M at 25 ° C., the concentration of Dy (acac) ₃ is 2.0 × 10 ⁻⁶ M, 4 0.0 × 10 ⁻⁶ M, 6.0 × 10 ⁻⁶ M, 8.0 × 10 ⁻⁶ M, 1.0 × 10 ⁻⁵ M, 2.0 × 10 ⁻⁵ M . The absorption spectrum of compound (1) changed through the isosbestic point (FIG. 2). This indicates that the compound (1) and dyspronium ion are associated, and the stoichiometric ratio of the aggregate is 1: 1. The association constant (K = 5.4 × 10 ⁷ ) was calculated from this spectrum change. Shimadzu UV-3101PC was used for the absorption spectrum measurement.
The calculation results of the association constants of boron dipyrromethene-calix [4] arene (1) and the lanthanoid metal group are summarized in Table 1 (described above). The present invention shows high selectivity for Dy (Dyspronium).

Comparative Example 5- (4-hydroxyphenyl) -boron dipyrromethene (compound represented by the following structural formula (4)) is used as a comparative compound of the lanthanoid series metal ligand of the present invention.
5- (4-Hydroxyphenyl) -boron dipyrromethene is produced by the following two steps.
(1) Synthesis of 5- (4-hydroxyphenyl) dipyrromethane (5) (2) Synthesis of 5- (4-hydroxyphenyl) -boron dipyrromethene (4)

具体的には以下の通りである。
（１） ５−（４−ヒドロキシフェニル）ジピロメタン（５）の合成
ｐ−ヒドロキシベンズアルデヒド１．２ｇ（１０ｍｍｏｌ）をピロール２５ｇ（０．３７ｍｏｌ）に溶解し、アルゴン雰囲気下１５分間攪拌した。反応容器を遮光し、触媒量のトリフルオロ酢酸を加え、さらに３０分攪拌した。トリエチルアミン２ｍｌを加え、反応を停止しポンプで過剰のピロールを留去した。残さをカラムクロマトグラフ法（シリカゲル、塩化メチレン−酢酸エチル−トリエチルアミン９０：１０：１）で精製を行った。ポンプを用いて溶媒を留去して５−（４−ヒドロキシフェニル）ジピロメタン（５）を１．９ｇ（８１％）を得た。
５−（４−ヒドロキシフェニル）ジピロメタン（５）の物性は以下の通りである。
ｍｐ１２８−１２９°Ｃ
^１Ｈ−ＮＭＲ（ＣＤＣｌ_３）d４．６９（１Ｈ，ｂｓ，ＯＨ），５．４２（１Ｈ，ｓ，Ａｒ−ＣＨ−（ｐｙｒｒｏｌｅ）_２），５．９１（２Ｈ，ｍ，ｐｙｒｒｏｌｅ−Ｈ），６．１５（２Ｈ，ｑ，ｐｙｒｒｏｌｅ−Ｈ），６．６９（２Ｈ，ｑ，ｐｙｒｒｏｌｅ−Ｈ），６．７６（２Ｈ，ｄ，Ｊ＝８．８Ｈｚ，Ａｒ−Ｈ），７．０８（２Ｈ，ｄ，Ｊ＝８．８Ｈｚ，Ａｒ−Ｈ），７．９２（２Ｈ，ｂｓ，ＮＨ）；
ｍａｓｓ ｓｐｅｃｔｒｕｍ（ＦＡＢ）ｍ／ｚ２３８（Ｍ^＋）
Ｐｒｅｃｉｓｅ Ｍａｓｓ ｍ／ｚ２３８．１０９５（Ｃ_１５Ｈ_１４Ｎ_２Ｏ２３８．１１０６）
ｅｌｅｍｅｎｔａｌ ａｎａｌｙｓｉｓ，ｃａｌｃｓ ｆｏｒＣ_１５Ｈ_１４Ｎ_２Ｏ：Ｃ，７５．６１％；Ｈ，５．９２％；Ｎ，１１．７６％．
Ｆｏｕｎｄ：Ｃ，７５．６２％；Ｈ，５．８８％；Ｎ，１１．６８％．
（２） ５−（４−ヒドロキシフェニル）‐ボロンジピロメテン（４）の合成
５−（４−ヒドロキシフェニル）ジピロメタン（５）１．２ｇ（５．２ｍｍｏｌ）を乾燥トルエン５０ｍｌに溶解しアルゴン雰囲気下１０分間攪拌した。この溶液にＤＤＱ１．２ｇ（５．２ｍｍｏｌ）加え、２０分間攪拌を続けた。トリエチルアミン５．１ｍｌ、トリフルオロボランジエチルエーテル錯体４．５ｍｌを加え、さらに４５分間攪拌を続けた。この反応溶液に塩化メチレンを１００ｍｌ加え、水で洗浄し、溶媒を減圧留去した。残さをカラムクロマトグラフ法（シリカゲル、塩化メチレン）で２度精製を行った。ヘキサンで再沈殿を行いオレンジ色の粉末として化合物（４）を５００ｍｇ（４２％）得た。
５−（４−ヒドロキシフェニル）‐ボロンジピロメテン（４）の物性
ｍｐ１７６−１７８°Ｃ
^１Ｈ−ＮＭＲ（ＣＤＣｌ_３）d５．４０（１Ｈ，ｂｓ，ＯＨ），６．５５（２Ｈ，ｄ，Ｊ＝４．０Ｈｚ，ｐｙｒｒｏｌｅ−Ｈ），６．９９（２Ｈ，ｄ，Ｊ＝８．４Ｈｚ，Ａｒ−Ｈ），７．４９（２Ｈ，ｄ，Ｊ＝８．４Ｈｚ，Ａｒ−Ｈ），７．９３（２Ｈ，ｂｓ，ｐｙｒｒｏｌｅ−Ｈ）
ｍａｓｓ ｓｐｅｃｔｒｕｍ（ＦＡＢ）ｍ／ｚ２８４（Ｍ^＋）
ＰｒｅｃｉｓｅＭａｓｓｍ／ｚ２８４．０９２９（Ｃ_１５Ｈ_１２ＢＦ_２Ｎ_２Ｏ２８４．０９３２）
比較例２ 5- (4-hydroxyphenyl) -boron dipyrromethene (a compound represented by the following structural formula (4)) can be produced as follows.

Specifically, it is as follows.
(1) Synthesis of 5- (4-hydroxyphenyl) dipyrromethane (5) 1.2 g (10 mmol) of p-hydroxybenzaldehyde was dissolved in 25 g (0.37 mol) of pyrrole and stirred for 15 minutes in an argon atmosphere. The reaction vessel was shielded from light, a catalytic amount of trifluoroacetic acid was added, and the mixture was further stirred for 30 minutes. 2 ml of triethylamine was added to stop the reaction, and excess pyrrole was distilled off with a pump. The residue was purified by column chromatography (silica gel, methylene chloride-ethyl acetate-triethylamine 90: 10: 1). The solvent was distilled off using a pump to obtain 1.9 g (81%) of 5- (4-hydroxyphenyl) dipyrromethane (5).
The physical properties of 5- (4-hydroxyphenyl) dipyromethane (5) are as follows.
mp128-129 ° C
¹ H-NMR (CDCl ₃ ) d 4.69 (1H, bs, OH), 5.42 (1H, s, Ar—CH— (pyrrole) ₂ ), 5.91 (2H, m, pyrorole-H), 6.15 (2H, q, pyrrole-H), 6.69 (2H, q, pyrrole-H), 6.76 (2H, d, J = 8.8 Hz, Ar-H), 7.08 (2H , D, J = 8.8 Hz, Ar-H), 7.92 (2H, bs, NH);
mass spectrum (FAB) m / z 238 (M ⁺ )
Precision Mass m / z 238.195 (C ₁₅ H ₁₄ N ₂ O 238.1106)
_{elemental analysis, calcs forC 15 H 14} N 2 O: C, 75.61%; H, 5.92%; N, 11.76%.
Found: C, 75.62%; H, 5.88%; N, 11.68%.
(2) Synthesis of 5- (4-hydroxyphenyl) -boron dipyrromethene (4) 1.2 g (5.2 mmol) of 5- (4-hydroxyphenyl) dipyrromethane (5) was dissolved in 50 ml of dry toluene under an argon atmosphere. Stir for 10 minutes. DDQ 1.2g (5.2mmol) was added to this solution, and stirring was continued for 20 minutes. Triethylamine (5.1 ml) and trifluoroborane diethyl ether complex (4.5 ml) were added, and stirring was further continued for 45 minutes. 100 ml of methylene chloride was added to the reaction solution, washed with water, and the solvent was distilled off under reduced pressure. The residue was purified twice by column chromatography (silica gel, methylene chloride). Reprecipitation was performed with hexane to obtain 500 mg (42%) of Compound (4) as an orange powder.
Properties of 5- (4-hydroxyphenyl) -boron dipyrromethene (4) mp 176-178 ° C
¹ H-NMR (CDCl ₃ ) d 5.40 (1H, bs, OH), 6.55 (2H, d, J = 4.0 Hz, pyrrole-H), 6.99 (2H, d, J = 8. 4 Hz, Ar-H), 7.49 (2H, d, J = 8.4 Hz, Ar-H), 7.93 (2H, bs, pyrole-H)
mass spectrum (FAB) m / z 284 (M ⁺ )
_{PreciseMassm / z284.0929 (C 15 H 12} BF 2 N 2 O284.0932)
Comparative Example 2

The fact that 5- (4-hydroxyphenyl) -boron dipyrromethene, which is a comparative object compound, does not show a sensing action with respect to a metal salt of a lanthanoid metal is as follows.
The comparative compound, 5- (4-hydroxyphenyl) -boron dipyrromethene (4), has a maximum absorption (λmax) at 505 nm at a concentration of 1.0 × 10 ⁻⁵ M in dimethylformamide (DMF) at 25 ° C. An absorption spectrum having Even when a metal salt of a lanthanoid metal (MX ₃ , X represents an acetylacetonate group) coexists in this solution (˜3.0 × 10 ⁻⁴ M), the absorption spectrum of the compound (4) is completely changed. No sensing interaction with rare metals could be detected (Fig. 1).

  Make new proposals for ligand design that enables selective sensing and separation of lanthanoid metal ions from lanthanoid series metal groups, and by pursuing these methods, approach the solution of the problem Can do. In addition, it can be expected to be connected to a method that enables separation and recovery of lanthanoid metal ions.

Claims (4)

Boron dipyrromethene-calix [4] arene (1).

Monodipyrromethane-calix [4] arene (structural formula (3)) is produced from pyrrole and monoformylcalixarene (structural formula (2)), and then monodipyrromethane-calix [4] arene (structural formula (3)) Boron dipyrromethene-calix [4] arene (1) (Structure (1)) is produced from a trifluoroboric acid diethyl ether complex (DDQ). ) Manufacturing method.

In a solution of boron dipyrromethene-calix [4] arene (1) in which an alkali metal ion or an alkaline earth metal ion is present, MX ₃ which is a lanthanoid series rare earth metal (M represents a lanthanoid series rare earth metal. X represents acetylacetate. The absorption spectrum of boron dipyrromethene-calix [4] arene (1) is calculated by adding (representing a nate group), and the association constant is calculated from this absorption spectrum. A method for sensing a lanthanoid series rare earth metal, comprising calculating a constant and calculating a concentration of an unknown sample based on the constant.   4. The dyspronium sensing method according to claim 3, wherein the lanthanoid series rare earth metal is dyspronium.

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