AU2013285053A1

AU2013285053A1 - Organic dyes comprising hydrazone moiety and use in dye- sensitized solar cells thereof

Info

Publication number: AU2013285053A1
Application number: AU2013285053A
Authority: AU
Inventors: Ingmar Bruder; Maryte Daskeviciene; Vytautas Getautis; Tadas Malinauskas; Robert SEND; Simona URNIKAITE
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2012-07-04
Filing date: 2013-06-26
Publication date: 2015-01-15
Also published as: JP2015528836A; EP2870204A2; WO2014006544A2; JP6257612B2; CN104411775A; EP2870204A4; WO2014006544A3; KR20150036349A

Abstract

Provided are compounds of general formula (I), the use for producing dye-sensitized solar cells and dye-sensitized solar cells comprising ompounds of formula (I).

Description

WO 2014/006544 PCT/IB2013/055252 Organic dyes comprising a hydrazone moiety and their use in dye-sensitized solar cells Description 5 The present invention relates to compounds of general formula I R R200 D--' NNA] - - m (I) wherein R 10 0 and R 200 are each independently hydrogen, C1-C10-alkyl which in case of 10 C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 0-alkyl by one or two non adjacent oxygen atoms, C 5 -Cr-cycloalkyl, aryl, aryl-C1-C10-alkyl or aryloxy-C1-C10-alkyl, o is an m-valent (m = 1, 2 or 3) donor moiety which comprises at least one carbon carbon or carbon-heteroatom double bond and/or at least one unfused or fused carbo or heterocyclic ring, A is an acceptor moiety which comprises at least one carbon 15 carbon or carbon-heteroatom double bond and/or at least one unfused or fused carbo or heterocyclic ring, and the donor moiety 0 and the acceptor moiety A are -rr conjugated to one another. Furthermore, the present invention relates to the use of compounds of formula I for 20 producing dye-sensitized solar cells and to dye-sensitized solar cells comprising compounds of formula 1. The direct conversion of solar energy to electrical energy in solar cells is based on the internal photoeffect of a semiconductor material, i.e. the generation of electron-hole 25 pairs by absorption of photons and the separation of the negative and positive charge carriers at a p-n junction or a Schottky contact. The photovoltage thus generated can bring about a photocurrent in an external circuit, through which the solar cell delivers its power. 30 Thin layers or films of metal oxides are known to constitute inexpensive solid semiconductor materials (n-semiconductors), but their absorption, owing to large band gaps, is typically not within the visible region of the electromagnetic spectrum. For use in solar cells, the metal oxides therefore have to be combined with a photosensitizer which absorbs in the wavelength range of sunlight, i.e. at from 300 to 2000 nm, and, in 35 the electronically excited state, injects electrons into the conduction band of the semiconductor. With the aid of a redox system which is used additionally in the cell and is reduced at the counterelectrode, electrons are recycled to the sensitizer which is thus regenerated.

WO 2014/006544 PCT/IB2013/055252 2 Of particular interest for use in solar cells are the semiconductors zinc oxide, tin dioxide and especially titanium dioxide, which are used in the form of nanocrystalline porous layers. These layers have a large surface area which is coated with the sensitizer, so that high absorption of sunlight is achieved. 5 Dye-sensitized solar cells (DSCs) which are based on titanium dioxide as the semiconductor material are described, for example, in US-A-4 927 721, Nature 353, p. 737-740 (1991) and US-A-5 350 644, and also Nature 395, p. 583-585 (1998) and EP A-1 176 646. These solar cells comprise monomolecular films of transition metal 10 complexes, especially ruthenium complexes, which are bonded to the titanium dioxide layer via acid groups, as sensitizers and iodine/iodide redox systems present in dissolved form or amorphous organic p-conductors based on spirobifluorenes. Ruthenium complexes as molecular sensitizers have shown impressive solar-to-electric 15 power conversion efficiencies (PCE) in liquid electrolyte based devices, with the PCE reaching over 11% under standard AM1.5G full sunlight as was shown by M. K. Nazeeruddin, F. De Angelis, S. Fantacci, A. Selloni, G. Viscardi, P. Liska, S. Ito, T. Bessho, M. Gr5tzel, J. Am. Chem. Soc. 2005, 127, 16835; 20 Y. Chiba, A. Islam, Y. Watanabe, R. Komiya, N. Koide, L. Y. Han, Jpn. J. Apple. Phys. 2006, 45, L638; F. Gao, Y. Wang, D. Shi, J. Zhang, M. K. Wang, X. Y. Jing, R. Humphry-Baker, P. Wang, S. M. Zakeeruddin, M. Gr5tzel, J. Am. Chem. Soc. 2008, 130, 10720; Y. M. Cao, Y. Bai, Q. J. Yu, Y. M. Cheng, S. Liu, D. Shi, F. Gao, P. Wang, J. Phys. 25 Chem. C 2009, 113, 6290; and C.-Y. Chen, M. K. Wang, J.-Y. Li, N. Pootrakulchote, L. Alibabaei, C. H. Ngoc-le, J. D. Decoppet, J .H. Tsai, C. Gratzel, C. G. Wu, S. M. Zakeeruddin, M. Gr5tzel, ACS Nano 2009,3,3103. 30 In recent years, metal-free organic dyes have attracted increasing attention as they do not contain any toxic or costly metal and their properties are easily tuned by facile structural modification. In addition, they generally have much higher extinction coefficients when compared to Ru(II) polypyridyls, making them excellent for use in 35 solid state DSCs in combination with hole transporting materials such as P3HT as shown, for example, by G. K. Mor, S. Kim, M. Paulose, 0. K. Varghese, K. Shankar, J. Basham and C. A. Grimes, Nano Lett., 2009, 9, 4250, or spiro-MeOTAD as shown, for example, by H. J. Snaith, A. J. Moule, C. Klein, K. Meerholz, R. H. Friend, M. Gr5tzel, Nano Lett., 2007, 7, 3372. 40 WO 2014/006544 PCT/IB2013/055252 3 US-A-6 359 211 describes cyanine, oxazine, thiazine and acridine dyes which have carboxyl groups bonded via an alkylene radical for securing to the titanium dioxide semiconductor. 5 Perylene-3,4:9,10-tetracarboxylic acid derivatives as sensitizers are examined in Japanese documents JP-A-10-189065, 2000-243463, 2001-093589, 2000-100484 and 10-334954, and in New J. Chem. 26, p. 1155-1160 (2002). The most extensively examined metal-free sensitizers at present include dyes which 10 possess a cyanoacrylate anchor group. For example, Kim, S.; Lee, J.K.; Kang, S.O.; Yum, J.H.; Fantacci, S.; DeAngelis, F.; Di Censo, D.; Nazeerruddin, M.K.; Gr5tzel, M. JACS 2006, 128, 16701 describes the compound COOH CN S S J__ N ("JK2") 15 and Solar Energy Materials & Solar Cells 2009, 93, 1143 the compound N CN COOH Dyes with naphthalene monoimide anchor groups are described in the document 20 WO 2008/132103 A1. To date the most efficient metal-free organic dyes for DSCs are based upon the D-ir-A (donor moiety - -rr-conjugation bridging moiety - acceptor moiety) architecture. With this construction it is possible to design new dye structures, extend the absorption spectra, adjust the energy levels and complete the intramolecular charge separation. 25 WO 2014/006544 PCT/IB2013/055252 4 DSCs employing organic dyes featuring an electron donor and acceptor moiety connected by a -rr-conjugation bridge have reached -10% efficiency with liquid electrolytes and up to 6% with solid HTM as shown for the former by 5 K. Hara, T. Sato, R. Katoh, A. Furube, Y. Ohga, A. Shinpo, S. Suga, K. Sayama, H. Sugihara, H. Arakawa, J. Phys. Chem. B 2003, 107, 597; T. Horiuchi, H. Miura, K. Sumioka, S. Uchida, J. Am. Chem. Soc. 2004, 126, 12218; 10 S. Kim, J. K. Lee, S. O. Kang, J. Ko, J.-H. Yum, S. Fantacci, F. DeAngelis, D. Di Censo, M. K. Nazeeruddin, M. Gr5tzel, J. Am. Chem. Soc. 2006, 128, 16701; D. P. Hagberg, T. Edvinsson, T. Marinado, G. Boschloo, A. Hagfeldt, L. C. Sun, Chem. Commun. 2006, 2245; 15 W. D. Zeng, Y. M. Cao, Y. Bai, Y. H. Wang, Y. S. Shi, M. Zhang, F. F. Wang, C. Y. Pan, P. Wang, Chem. Mater. 2010, 22, 1915. and for the latter by 20 N. Cai, S.-J. Moon, L. Cevey-Ha, T. Moehl, R. Humphry-Baker, P. Wang, S. M. Zakeeruddin, M. Gr5tzel, Nano Lett. 2011, 11, 1452; X. Liu, W. Zhang, S. Uchida, L. Cai, B. Liu, S. Ramakrishna, Adv. Mater. 2010, 22, 25 E150. A large variety of donors has been investigated, like tetrahydroquinoline, indoline, coumarin, triarylamine, heteroanthracene, carbazole, NN-dialkylaniline, and fluorene derivatives. The majority of these dyes contain thiophene derivatives or ethenyl 30 fragments of various length as -rr-conjugation bridges, as disclosed, for example, in A. Mishra, M. K. R. Fischer, P. Bauerle, Angew. Chem. 2009, 121, 2510; A. Mishra, M. K. R. Fischer, P. Bauerle Angew. Chem. Int. Ed. 2009, 48, 2474; 35 A. Hagfeldt, G. Boschloo, L. Sun, L. Kloo, H. Pettersson Chem. Rev. 2010, 110, 6595; C. Li, M. Liu, N. G. Pschirer, M. Baumgarten, K. MOllen Chem. Rev., 2010, 110, 6817; Y. Ooyama, Y. Harima Eur. J. Org. Chem. 2009, 2903. 40 WO 2014/006544 PCT/IB2013/055252 5 Those bridging units are shown to be very effective; however, their synthesis often involves organotin, organolithium, or organomagnesium reagents, expensive palladium or nickel catalysts, rigorously anhydrous and oxygen-free conditions. 5 Hydrazone derivatives, on the other hand, are known for their low cost, simple synthesis, and rapid charge transporting ability, as shown by R. Lygaitis, V. Getautis, J. V. Grazulevicius, Chem. Soc. Rev. 2008, 37, 770. Further dyes comprising hydrazone moieties are described in P. Shen, X. Liu, S. Jiang, 10 Y. Huang, L. Yi, B. Zhao, S. Tan, Org. Electronics, 12 (2011), 1992 - 2002 and P. Shen, X. Liu, S. Jiang, L. Wang, L. Yi, D. Ye, B. Zhao, S. Tan, Dyes and Pigments, 92 (2012), 1042 - 1051. In these documents the hydrazone moieties, however, do not constitute the rr -conjugation bridge but rather function as part of the donor moiety. 15 In view of the aforesaid it is the main object of the present invention to provide further efficient, metal-free organic dyes based upon the D- rr -A architecture for the application in DSCs and, preferrably, sDSCs which exhibit good to very good quantum efficiencies with very good medium to long term stabilities. 20 Accordingly, compounds of the formula I R R200 D NN A - - m (I) have been synthesized, wherein 25

R

1 00 and R 2 0 0 are each independently hydrogen, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, C 5

-C

7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl or aryloxy-Ci-Cio-alkyl, D is an m-valent donor moiety which comprises at least one carbon-carbon or carbon 30 heteroatom double bond and/or at least one unfused or fused carbo- or heterocyclic ring, A is an acceptor moiety which comprises at least one carbon-carbon or carbon heteroatom double bond and/or at least one unfused or fused carbo- or heterocyclic ring, and the donor moiety D and the acceptor moiety A are r-conjugated to one another. 35 In the context of the present application Ci-Cio-alkyl should be understood to mean linear or branched alkyl, for example methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, WO 2014/006544 PCT/IB2013/055252 6 sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl and n decyl. Preferred groups are methyl, isopropyl, n-butyl, tert-butyl and 2-ethylhexyl; in the radicals mentioned, it is optionally possible for one or more hydrogen atoms to be replaced by fluorine atoms, such that these radicals may also be partly fluorinated or 5 perfluorinated. Ci-Cio-Alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

10 alkyl by one or two nonadjacent oxygen atoms is, for example, 3-methoxyethyl, 2- and 3-methoxypropyl, 2-ethoxyethyl, 2- and 3-ethoxypropyl, 2-propoxyethyl, 2- and 3 10 propoxypropyl, 2-butoxyethyl, 2- and 3-butoxypropyl, 3,6-dioxaheptyl and 3,6 dioxaoctyl. The Ci-Cio-alkoxy, Ci-Cio-alkylamino-, di(Ci-Cio-alkyl)amino, Ci-Cio-alkylamino sulfonylamino-, di(Ci-Cio-alkyl)aminosulfonylamino and Ci-Cio-alkylsulfonylamino 15 radicals are correspondingly derived from the aforementioned C1-C1o-alkyl radicals, where, in the case of the di(Ci-Cio-alkyl)amino groups, either identical or different C 1 C 1 o-alkyl radicals may be present on the amino group. Examples include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isbutoxy, sec-butoxy, tert-butoxy, n-pentoxy, n-hexoxy, n-heptoxy, n-octoxy, 2-ethylhexoxy, n-nonoxy and n-decoxy, methylamino, 20 ethylamino, n-propylamino, isopropylamino, n-butylamino, isobutylamino, sec butylamino, tert-butylamino, n-pentylamino, n-hexylamino, n-heptylamino, n-octyl amino, 2-ethylhexylamino, n-nonylamino and n-decylamino, dimethylamino, diethyl amino, di(n-propyl)amino, diisopropylamino, di(n-butyl)amino, diisobutylamino, di(sec butyl)amino, di(tert-butyl)amino, di(n-pentyl)amino, di(n-hexyl)amino, di(n-heptyl)amino, 25 di(n-octyl)amino, di(2-ethylhexyl)amino, di(n-nonyl)amino and di(n-decyl)amino, and also the corresponding mixed dialkylamino radicals, for instance methylethylamino to methyl-n-decylamino, ethyl-n-propylamino to ethyl-n-decylamino, etc., and also methyl aminosulfonylamino, ethylaminosulfonylamino, n-propyl-aminosulfonylamino, isopropyl aminosulfonylamino, n-butylaminosulfonylamino, isobutylaminosulfonylamino, sec 30 butylaminosulfonylamino, tert-butylaminosulfonylamino, n-pentylaminosulfonylamino, n hexylaminosulfonylamino, n-heptylaminosulfonylamino, n-octylaminosulfonylamino, 2 ethylhexylaminosulfonyl-amino, n-nonylaminosulfonylamino and n-decylaminosulfonyl amino, dimethylaminosulfonylamino, diethylaminosulfonylamino, di(n-propyl)amino sulfonylamino, diisopropylaminosulfonylamino, di(n-butyl)aminosulfonylamino, diiso 35 butylaminosulfonylamino, di(sec-butyl)amino-sulfonylamino, di(tert-butyl)amino sulfonylamino, di(n-pentyl)aminosulfonylamino, di(n-hexyl)aminosulfonylamino, di(n heptyl)aminosulfonylamino, di(n-octyl)aminosulfonylamino, di(2-ethylhexyl)amino sulfonylamino, di(n-nonyl)amino-sulfonylamino and di(n-decyl)aminosulfonylamino, and also the corresponding radicals comprising mixed dialkylamino radicals, for instance 40 methylethylaminosulfonylamino to methyl-n-decylaminosulfonylamino, ethyl-n-propyl aminosulfonylamino to ethyl-n-decylaminosulfonylamino etc., up to n-nonyl-n-decyl aminosulfonylamino, and also methylsulfonylamino, ethylsulfonylamino, n-propyl- WO 2014/006544 PCT/IB2013/055252 7 sulfonylamino, isopropylsulfonylamino, n-butylsulfonylamino, isobutylsulfonylamino, sec-butylsulfonylamino, tert-butylsulfonylamino, n-pentylsulfonylamino, n-hexylsulfonyl amino, n-heptylsulfonylamino, n-octylsulfonylamino, 2-ethylhexylsulfonylamino, n nonylsulfonylamino and n-decylsulfonylamino. 5

C

5

-C

7 -Cycloalkyl is understood to mean especially cyclopentyl, cyclohexyl and cycloheptyl. In the context of the present invention, aryl is an aryl radical, aryl unit or aryl group 10 especially with a base skeleton of 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, and comprises mono- or polycyclic aromatic hydrocarbon radicals which may be unsubstituted or substituted. Aryl is preferably phenyl, tolyl, xylyl, mesityl, duryl, naphthyl, quinolinyl, fluorenyl, carbazolyl, anthracenyl, phenanthrenyl, stilbyl, 4(2,2 diphenylethenyl)phenyl or naphthyl, more preferably phenyl or naphthyl, where these 15 aryl groups, in the case of substitution, may bear generally 1, 2, 3, 4 or 5, preferably 1, 2 or 3, substituents which are selected from the group of radicals consisting of halogen, C1-C1o-alkyl, C1-C1o-alkoxy, cyano, nitro, -C(Ra)=N-NRaRb, -SO 2 NRaRb, -NHSO 2 NRaRb, -CONRaRb and -CO 2 Ra, where the Ci-Cio-alkoxy groups derive from the C1-Cio-alkyl groups listed above. Ra and Rb are preferably each independently hydrogen, aryl, 20 preferably phenyl, or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms. The aryl-Ci-Cio-alkyl and aryloxy-C1-C1o-alkyl groups derive from the alkyl and aryl groups listed above by formal replacement of one hydrogen atom of the linear or 25 branched alkyl chain by an aryl or aryloxy group. Preferred groups here are benzyl and linear aryloxy-Ci-Cio-alkyl, where, in the case of C 2

-C

1 o-alkyl radicals, the aryloxy radical is preferably bonded terminally. In the context of the present invention, alkali metal cation as the definition of M is 30 preferably lithium, sodium, cesium or potassium, more preferably sodium. In the context of the present invention, halogen denotes fluorine, chlorine, bromine or iodine, especially fluorine and chlorine. 35 Preference is given to compounds of formula I wherein in general formula I

R

1 00 is hydrogen or C 1

-C

4 -alkyl and 40

R

20 0 is aryl or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms.

WO 2014/006544 PCT/IB2013/055252 8 Further preference, also with reference to the aforementioned preference, is given to compounds, wherein the donor moiety D in general formula I for m = 1: 5 is selected from the group consisting of R 10R 140 R 150 R14 1510R R R210 R 210 20 - N 25 N R220/ R 220/ Z (D(4 ) (D02) (D03) R10 R 150 R1010210 R10 120 R R N 15N R 2 NR23 R250 R 20 R R 220/250 N R R x (D04) (D05) (D06) R 130

R

140 R160 10 2 R50 2NC 1410 R 1210 230 R120 and N R 16 N 110' R 15 110 220 N N N4 1250 R 1250 R R 2 (D07) RR (D09) 260 0 R1 R 1 140, r120 Z R hle h

R

150 NQ 110' N N 1250 R \ 250 \ N 5 (DC-k) w (D hi ) R (D12 10 110 R~R 21 0 15 oand N case o (D13) 120 C130 R R 10 (D14) and

R

1 1 0 , R 120 and R 130 are each independently hydrogen, halogen, hydroxyl, Ci Cio-alkyl which in case of C 2 -alkyl may be interrupted by 15 one and in case of C 3 -Clo-alkyl by one or two nonadjacent oxygen atoms, C 5

-C

7 -CyCloalkyl, C 1 -Cio-alkoxy, C 1

-C

10

-

WO 2014/006544 PCT/IB2013/055252 9 alkylamino, di(Ci-Cio-alkyl)amino, Ci-Cio-alkylamino- or di(Ci-Cio-alkyl)aminosulfonylamino, C1-C1o alkylsulfonylamino, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio alkyl or an -NHCOR 1 70 or -NHCOOR 17 0 radical, 5

R

14 0 , R 150 and R 160 are each independently hydrogen, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of

C

3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, C 5 C 7 -cycloalkyl, aryl aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or 10 in case R 140 and R 1 60 or R 150 and R 160 are bonded to adjacent carbon atoms these pairs of groups may together with the carbon atoms to which they are bonded form a five- or six-membered ring in which one CH 2 group may be replaced by an oxygen atom, 15 R170 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, 20

R

2 10 , R 2 2 0 , R 2 3 0 and R 2 4 0 are each independently aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci

C

1 o-alkyl, C 1

-C

1 o-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, Cs-C1o-cycloalkyl, or R 210 25 and R 2 20 and/or R 23 0 and R 2 40 form, together with the nitrogen atom to which they are bonded, a five- or six membered ring in which one CH 2 group not adjacent to the nitrogen atom may be replaced by an oxygen atom, or in case NR 2 10

R

22 0 and R 11 0 are bonded to adjacent carbon 30 atoms, R 11 0 and R 21 0 or R 1 10 and R 220 -together with the nitrogen atom of the moiety NR 2 10

R

2 2 0 and the carbon atom to which the moieties NR 2 10

R

2 2 0 and R 11 0 are bonded- form a five- or six-membered ring in which one

CH

2 group not adjacent to the nitrogen atom may be 35 replaced by an oxygen atom and which five- or six membered ring may be fused to another five- or six membered saturated or unsaturated ring,

R

250 and R 260 are each independently C 1

-C

1 o-alkyl which in case of C 2 40 alkyl may be interrupted by one and in case of C 3

-C

10 alkyl by one or two nonadjacent oxygen atoms, C 5

-C

7 cycloalkyl, aryl, aryl-Ci-Cio-alkyl or aryloxy-Ci-Cio-alkyl WO 2014/006544 PCT/IB2013/055252 10 and Z is O or S, 5 for m = 2: is selected from the group consisting of: R17

R

170 R 17 0 R170 H 3 C CH 3 R

H

3 C CH 3 N N \/ \/\I and 10 where R 1 7 0 has the meaning given before and in case of two moities may vary independently of each other, and for m = 3: is selected from the group consisting of: I II 15

R

170

H

3 C CH 3 15| | NN N and N where R 1 7 0 has the meaning given before. 20 Further preference, also with reference to the aforementioned preference with respect to R 100 and R 2 0 0 , is given to compounds, wherein the donor moiety D in general formula I for m = 1: WO 2014/006544 PCT/IB2013/055252 11 is selected from the group consisting of: R R 150 140 R R R210R\ N R NR 210 N220 N N-6 RN.I '\ (D01) (D02) R (D03) (D06) \ 130 R R110 110 R 140 NC R 110 R210 R10 R150 N R210

R

230 and R 220 / N 1101 NA 160 N 2 R22 240 120 130 R (D09) R R (DO7) (D14) 5 for m = 2: is selected from the group consisting of:

H

3 C CH 3 170 170 N N and and for m = 3: 10 is selected from the group consisting of: N N and and the variables have the aforementioned meaning. 15 Particular preference, also with reference to the aforementioned preference with respect to R 1 00 and R 2 0 0 , is given to compounds, wherein the donor moiety D in general formula 1 20 for m = 1: is a moiety: WO 2014/006544 PCT/IB2013/055252 12 R110 210 R220/ (D01) and 5

R

11 0 is hydrogen, halogen, hydroxyl, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 Cio-alkyl by one or two nonadjacent oxygen atoms, C 5

-C

7 cycloalkyl, C1-Cio-alkoxy, Ci-Cio-alkylamino, di(C1-C1o 10 alkyl)amino, C1-Cio-alkylamino- or di(C1-C1o alkyl)aminosulfonylamino, Ci-Cio-alkylsulfonylamino, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or an -NHCOR 1 70 or -NHCOOR 17 0 radical, 15 R 17 0 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, 20 and

R

2 10 and R 2 2 0 are each independently aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci C1o-alkyl, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or 25 two nonadjacent oxygen atoms, C 5 -C1o-cycloalkyl, or R 2 1 0 and R 2 20 form, together with the nitrogen atom to which they are bonded, a five- or six-membered ring in which one CH 2 group not adjacent to the nitrogen atom may be replaced by an oxygen atom, or in case NR 2 10

R

2 2 0 and 30 R 11 0 are bonded to adjacent carbon atoms, R 11 0 and R 2 10 or R 1 10 and R 2 2 0 -together with the nitrogen atom of the moiety NR 2 10

R

2 2 0 and the carbon atom to which the moieties NR 2 10

R

22 0 and R 1 10 are bonded- form a five- or six-membered ring in which one CH 2 group not adjacent 35 to the nitrogen atom may be replaced by an oxygen atom and which five- or six-membered ring may be fused to another five- or six-membered saturated or unsaturated ring, WO 2014/006544 PCT/IB2013/055252 13 for m = 2: is selected from the group consisting of: 170 170 N N \\/ and 5 where R 1 7 0 has the meaning given before, and for m = 3: is a moiety 10 N Further preference, also with reference to the aforementioned preferences with respect to the donor moiety D and R 1 00 and R 200 , is given to compounds, wherein the acceptor 15 moiety A in general formula I is a group of formula la: R340 A* (la) werein A* denotes a moiety selected from the group consisting of R310 CN R O3 N R3 ON * 0 *4 N-, R 410 * 0 * NN N N / I 0 0 N N N 00 3204) (AOl) (A02) (A03) R30 2 A4 WO 2014/006544 PCT/IB2013/055252 14 RN 330 R330 * 0 * * 410 and * R4 N (A05) (A06) (A07) (A08) and 5 * indicates the position which the double bond of the group of formula la is bonded to,

R

3 10 and R 3 2 0 are each independently hydrogen, Ci-Cio-alkyl which in 10 case of C 2 -alkyl may be interrupted by one and in case of

C

3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, or

C

5

-C

7 -cycloalkyl, R 330 is hydrogen, C1-Cio-alkyl which in case of C 2 -alkyl may be 15 interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, partly fluorinated C 1

-C

10 alkyl, perfluorinated Ci-Cio-alkyl, C 5

-C

7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl or aryloxy-Ci-Cio-alkyl, 20 R 34 0 is hydrogen, NO 2 , CN, COR 3 5 0 , COOR 3 5 0 , S0 2

R

3 5 0 or S03R 350 ,

R

3 50 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio alkyl which in case of C 2 -alkyl may be interrupted by one 25 and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, R 410 is hydrogen, C1-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or 30 two nonadjacent oxygen atoms and which may be mono or polysubstituted by hydroxyl, mercapto, halogen, cyano, nitro, -COOM and/or -COOR 4 2 0 , C 5

-C

7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl, or an -NHCOR 4 2 0 or -N(CO R 4 20

)

2 radical where the two R 4 2 0 in the latter 35 may be the same or different, X is independently CH or N, WO 2014/006544 PCT/IB2013/055252 15 Y is 0, C(CN) 2 , C(CN)(COOM) or C(CN)(COOR 420 ), M is alkali metal cation or [NR 4 2 0 4 +, 5 and R420 is hydrogen, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two 10 nonadjacent oxygen atoms. Further preference, also with reference to the aforementioned preferences with respect to the donor moiety D and R 1 00 and R 2 0 0 , is given to compounds, wherein the acceptor moiety A in general formula I is: 15 R 340 s

IN-R

4 10 (AO1) and 20 R 340 is hydrogen, NO 2 , CN, COR 3 50 , COOR 3 50 , S0 2

R

3 50 or S03R 350 ,

R

350 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio alkyl which in case of C 2 -alkyl may be interrupted by one 25 and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms, R410 is hydrogen, C1-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or 30 two nonadjacent oxygen atoms and which may be mono or polysubstituted by hydroxyl, mercapto, halogen, cyano, nitro, -COOM and/or -COOR 420 , C 5

-C

7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl, or an -NHCOR 420 or -N(CO R 4 20

)

2 radical where the two R 4 2 0 in the latter 35 may be the same or different, M is alkali metal cation or [NR 4 2 0 4 +, and WO 2014/006544 PCT/IB2013/055252 16 R420 is hydrogen, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms. 5 Particular preference, also with reference to the aforementioned preferences with respect to the donor moiety D and R 1 00 and R 200 , is given to compounds wherein the acceptor moiety A in general formula I is: R 340 s N -R41 10 (AO1) and R340 is hydrogen, NO 2 , CN, COR 3 50 , COOR 3 50 , S0 2

R

3 50 or 15 S0 3

R

3 50 ,

R

350 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent 20 oxygen atoms, R410 is aryl or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms and which is terminally 25 substituted by hydroxyl, -COOM or -COOR 42 0 , M is alkali metal cation or [NR 4 2 0 4 +, and 30 R420 is hydrogen or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3

-C

1 o-alkyl by one or two nonadjacent oxygen atoms. 35 As a result of the preparation, it is possible in the individual case that a compound shown explicitly is not obtained, but rather an isomeric compound thereof, or that mixtures of isomers are also obtained. According to the invention, the isomeric compounds of the general formula I or the isomers of the corresponding preferred and WO 2014/006544 PCT/IB2013/055252 17 particularly preferred compounds of general formula I, and also mixtures of isomers, shall accordingly also be comprised. The preparation of the compounds of general formula I follows well established routes 5 known to the person skilled in the art. Typically, donor moieties D with m aldehyde functions (m = 1, 2 or 3) are reacted with a hydrazine derivative or formula R 200

H

2 N' N A to deliver the desired hydrazones. 10 For preferred compounds comprising acceptor moieties A of formula la R A* (la) a favorable route comprises reacting fluoro-benzaldehyde with the hydrazone 15 according to the scheme - -0 R R200 10 2 200 0 D NR -- m m0 -mand further reacting the resulting aldehyde with the C-H acidic compounds underlying the moieties A*. 20 With respect to the exemplified A* moieties A01 to A08 above these educt compounds are (in the same order): R310 CN H2 N , H , H 'H2 O S R310 CNR310 C O N N N 0 "' 4 1 0 / 02 320 R 33030 R R 330 R 0 H 2 C 0 ' H 2 C N , 410 a nd H 2 C Y R 340 0

Y

WO 2014/006544 PCT/IB2013/055252 18 Further details on the preparation of the compounds according to the instant invention can be taken from the experimental section. Also claimed in the context of the present invention is the use of compounds of formula 5 I and their aforementioned preferences for producing dye-sensitized solar cells. Further claimed according to the instant invention is a dye-sensitized solar cell comprising compounds of formula I and their aforementioned preferences. 10 DSCs generally comprise the following elements: an electrically conductive layer (being part of or forming the working electrode or anode), a photosensitive layer generally comprising a semi-conductive metal oxide and a photosensitive dye, a charge transfer layer and another electrically conductive layer (being part of or forming the counter electrode or cathode). 15 Regarding further details of the construction of sDSCs particular reference is made to WO 2012/001628 Al, which is hereby fully incorporated by reference. Experimental part 20 A) Preparation of compounds according to the invention Materials and Methods 25 Chemicals were purchased from Aldrich and TCI Europe and used as received without further purification. 2-lodofluorene (S. H. Lee, T. Nakamura, T. Tsutsui, Org. Lett. 2001, 3, 2005), 9,9-dimethyl-2-iodofluorene (C. H. Huang, S. H. Yang, K. B. Chen, C. S. Hsu, J. Polym. Sci. Part A: Polym. Chem. 2006, 44, 519), and N,N-bis(9,9-dimethylfluoren-2 yl)aniline (H. Doi, M. Kinoshita, K. Okumoto, Y. Shirota, Chem. Mater. 2003, 15, 1080) 30 were synthesized according to the citations in parentheses, 4-[bis(4-methylphenyl) amino]benzaldehyde was purchased from TCI Europe. The 1 H and 13 C NMR spectra were taken on Varian Unity Inova (300 MHz) spectrometer at room temperature. All the data are given as chemical shifts in 6 (ppm), 35 (CH3) 4 Si (TMS, 0 ppm) was used as an internal standard. The course of the reactions products were monitored by TLC on ALUGRAM SIL G/UV254 plates and developed with 12 or UV light. Silica gel (grade 9385, 230-400 mesh, 60 A, Aldrich) was used for column chromatography. Elemental analysis was performed with an Exeter Analytical CE-440 Elemental. IR-spectroscopy was performed on a Perkin Elmer Spectrum BX || 40 FT-IR System, using KBr pellets. Mass spectra (MS) were recorded on an Aligent 110 (series MS with VL) apparatus. The UV spectra were recorded on a Perkin Elmer WO 2014/006544 PCT/IB2013/055252 19 Lambda 35 spectrometer. 104 M solution of investigated dye in CHCl 3 and microcell with an internal width of 1 mm was used. Al) Preparation of dyes D1 to D9 5 Generalized procedure Condensation of the aldehyd 1 with phenyl hydrazine yielded hydrazone 2

H

2 N-N R RN\H 1N X\/ N R/ 0 N // \N- N R ()toluene/2-propanol, AT (2) (1)b 10 which was used in the arylation reaction with 4-fluorobenzaldehyde to yield compound 3 according to Route A) Route A) F \ R \ R \ N N _ N-N H K2CO3, DMF, AT, 16 h N-N (2) (3) " 0 or alkylation reaction with 1 -bromopropane and formylation of the alkylated inter mediate 4 by the Vilsmeier-Haack method to yield compound 5 according to route B) 15 Route B) R -CH3 R CH 3 N - N R/ R/ N-N KOH,THF,AT,3.5h RN-N H (2) (4) R CH 3 POC13/DMF ,N N-N 600C, 50 min (5) / \ -o Finally, condensation of the aldehydes 3 and 5 with rhodanine-3-acetic acid yielded dyes ID-1276 (D1), ID-1261 (D2), ID-1300 (03), ID-1332 (D4), ID-1464 (D5) and ID- WO 2014/006544 PCT/IB2013/055252 20 1509 (D7) and with rhodanine-3-benzoic acid dye ID-1 465 (D6), respectively. The variables R in the reaction routes shown before can be taken explicitly from the specific synthetic procedures. 5 Preparation of Dye D1 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo-1,3 thiazolidin-5-ylidenmethyl)phenyl-N-phenylhydrazone

CH

3 N S N'- N

H

3 C N HO 10 A mixture of compound 3 (0.76 g, 1.54 mmol; both radicals R equal 4-methylphenyl), rhodanine-3-acetic acid (0.35 g, 1.85 mmol) and ammonium acetate (0.03 g, 0.46 mmol) was refluxed in acetic acid (5.0 mL) for 3 h. Afterwards, water (15 mL) was added and the extraction was done with chloroform. The organic layer was dried over 15 anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using 7:18 v/v acetone/hexane followed by 7:1:17 v/v acetone/methanol/toluene as an eluent to collect dye D1 as a dark red solid (0.46 g, 45 %). 20 1 H NMR (300 MHz, DMSO-d 6 , 6): 7.94 - 6.69 (m, 24H), 4.58 (s, 2H, CH 2 ), 2.26 (s, 6H, CH3); 13 C NMR (75 MHz, DMSO-d 6 , 6): 193.48, 168.34, 167.39, 150.98, 149.43, 146.87, 144.85, 143.57, 138.39, 135.38, 133.69, 131.15, 130.85, 128.27, 126.27, 126.89, 25 125.59, 121.12, 119.08, 117.87, 115.36, 47.02, 30.32, 21.15; IR (KBr): v = 3486 (OH); 3025 (aromatic CH); 2977, 2918, 2859 (aliphatic CH); 1708 (C=O); 1575,1504 (C=C); 1294 (C=S); 1198, 1175,1105 (C-N); 863, 815 (CH=CH of 1,4-disubstituted benzenes), 781, 745, 718 (CH=CH of monosubstituted benzene); 30 Anal. calcd for C 3 9

H

3 2

N

4 0 3

S

2 (%): C 70.04, H 4.82, N 8.38; found: C 70.19, H 4.88, N 8.17. Preparation of Dye D2 35 WO 2014/006544 PCT/IB2013/055252 21 a) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-phenyl-N-propylhydrazone (D2-1; corresponds to compound 4 where both radicals R equal 4-methylphenyl)

CH

3 N OH 3

H

3 C N N 6 5 To a refluxing mixture of compound 2 (1.45 g, 3.70 mmol; both radicals R equal 4 methylphenyl), dissolved in mixture of anhydrous tetrahydrofuran (3 mL) and 1 bromopropane (1 mL), powdered KOH (0.62 g, 11.11 mmol) and anhydrous Na 2

SO

4 (0.21 g, 1.48 mmol) were added in three equal portions every 1 h. After 3.5 hours the reaction mixture was extracted with ethyl acetate and distilled water until neutral. The 10 organic layer was dried over anhydrous Na 2

SO

4 , filtered off and ethyl acetate was removed. The residue was washed with a mixture of 2-propanol and n-hexane (1:1) to give compound D2-1 as yellow solid (1.53 g, 96 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.52 (d, J = 8.6 Hz, 2H), 7.36 (s, 1H), 7.36 - 7.20 (m, 15 4H), 7.09 - 6.95 (m, 1 OH), 6.91 - 6.83 (m, 1 H), 3.83 (t, J = 7.7 Hz, 2H), 2.30 (s, 6H), 1.78 - 1.62 (m, 2H), 1.02 (t, J = 7.3 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 , 6): 147.83, 147.28, 145.09, 132.55, 131.07, 130.22, 129.84, 128.99, 126.71, 124.62, 122.45, 119.82, 114.41, 46.77, 20.80, 18.28, 11.35; 20 Anal. calcd for C 30

H

31

N

3 (%): C 83.10, H 7.21, N 9.69; found: C 83.33, H 7.10, N 9.57. b) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-(4-formyl)phenyl-N-propylhydrazone (D2-2)

CH

3 N CH 3

H

3 C N 25 Phosphorus oxychloride (0.16 mL, 1.73 mmol) was added dropwise to DMF (0.85 mL, 11.04 mmol), not allowing the temperature of the mixture to rise above 5 'C. A solution WO 2014/006544 PCT/IB2013/055252 22 of 17 (0.50 g, 1.15 mmol) in DMF (2.15 mL) was added, and the resulting mixture was heated at 60 'C for 30 min. The hot reaction mixture was poured into the ice-water, neutralized by adding sodium acetate (0.42 g, 5.19 mmol) aqueous solution, and extracted with ethyl acetate. The organic layer was dried over anhydrous Na 2

SO

4 , 5 filtered, and solvent evaporated. The crude product was purified by column chromatography using 1.5:2:20 v/v acetone/diethyl ether/hexane as an eluent to collect compound D2-2 as a yellow solid (0.18 g, 34 %). 1 H NMR (300 MHz, CDCl 3 , 6): 9.82 (s, 1H, CHO), 7.79 (d, J = 9.0 Hz, 2H), 7.62 (s, 1H), 10 7.55 (d, J = 8.8 Hz, 2H), 7.41 (d, J = 8.8 Hz, 2H), 7.12 - 6.96 (m, 10H), 3.90 (t, J = 7.8 Hz, 2H, CH 2

CH

2 CH3), 2.32 (s, 6H, CH3), 1.81 - 1.66 (m, 2H, CH 2

CH

2 CH3), 1.05 (t, J = 7.3 Hz, 3H, CH 2

CH

2 CH3); 13 C NMR (75 MHz, CDCl 3 , 6): 190.65, 151.55, 148.89, 144.77, 134.97, 133.15, 131.62, 15 129.95, 128.55, 128.18, 127.37, 125.01, 121.67, 113.27, 45.94, 20.83, 18.48, 11.27; Anal. calcd for C 3 1

H

3 1

N

3 0 (%): C 80.66, H 6.77, N 9.10; found: C 80.53, H 6.90, N 9.02. c) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo 20 1,3-thiazolidin-5-ylidenmethyl)phenyl-N-propylhydrazone (D2)

CH

3 N S

H

3 C NNN HO

CH

3 A mixture of D2-2 (0.165 g, 0.35 mmol), rhodanine-3-acetic acid (0.08 g, 0.11 mmol), and ammonium acetate (0.01 g, 0.11 mmol) was refluxed in acetic acid (0.6 mL) for 30 25 min. Afterwards, water (10 mL) was added and the extraction was done with ethyl acetate. The combined organic layer was washed with water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by column chromatography using 23:2 v/v toluene/methanol as an eluent to collect dye D2 as a dark red solid (0.18 g, 80%). 30 1 H NMR (300 MHz, CDCl 3 , 6): 7.62 - 6.59 (m, 19H), 4.70 (s, 2H, CH 2 ), 3.62 (t, J = 7.8 Hz, 2H, CH 2

CH

2 CH3), 2.30 (s, 6H, CH 3 ), 1.69 - 1.40 (m, 2H, CH 2

CH

2 CH3), 0.90 (t, J = 7.3 Hz, 3H, CH 2

CH

2 CH3); WO 2014/006544 PCT/IB2013/055252 23 13 C NMR (75 MHz, CDCl 3 , 6): 192.6, 170.0, 167.3, 148.46, 144.83, 143.59, 135.1, 134.12, 132.91, 129.91, 128.99, 128.18, 127.13, 125.94, 124.87, 121.74, 113.82, 47.1, 45.69, 21.2, 20.8, 18.10, 11.23; 5 IR (KBr): v = 3391 (OH), 3025 (aromatic CH); 2961, 2919, 2871 (aliphatic CH); 1705 (C=O); 1601, 1575, 1504 (C=C); 1293 (C=S); 1181, 1100 (C-N); 815 (CH=CH of 1,4 disubstituted benzenes); Anal. calcd for C 3 6

H

3 4

N

4 0 3

S

2 (%): C 68.11, H 5.40, N 8.83; found: C 68.00, H 5.26, N 10 8.61. Preparation of Dye D3 a) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde (D3-1; corresponds to 15 compound 1 where both radicals R equal 9,9-dimethyl-9H-fluoren-2-yl)

H

3 C

H

3 C NO

CH

3

CH

3 Phosphorus oxychloride (1.30 mL, 14.13 mmol) was added portion-wise to DMF (1.1 mL, 14.13 mmol), not allowing the temperature of the mixture to rise above 5 'C. N,N bis(9,9-dimethylfluoren-2-yl)aniline (4.50 g, 9.42 mmol) was then added and the 20 resulting mixture was heated at 90 'C for 4 h. The hot reaction mixture was poured into ice-water and neutralized by adding sodium acetate (3.47 g, 42.39 mmol) aqueous solution. After extraction with ethyl acetate and distilled water, the organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent was evaporated. The crude product was purified by column chromatography using 3:22 v/v acetone/n-hexane as an eluent 25 to collect compound D3-1 as a yellow solid (4.20 g, 88%). 1 H NMR (300 MHz, CDCl 3 , 6): 9.83 (s, 1 H, CHO), 7.76 - 7.60 (m, 6H), 7.43 - 7.11 (m, 12H), 1.42 (s, 12H, CH3); 30 13 C NMR (75 MHz, CDCl 3 , 6): 190.36, 155.37, 153.59, 145.58, 138.47, 136.11, 131.29, 129.21, 127.03, 124.78, 122.55, 120.90, 120.27, 119.96, 119.72, 46.90, 26.96; Anal. calcd for C 3 7

H

3 1 NO (%): C 87.89, H 6.18, N 2.77; found: C 87.95, H 6.27, N 2.70.

WO 2014/006544 PCT/IB2013/055252 24 b) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde-N-phenylhydrazone (D3-2; corresponds to compound 2 where both R equal 9,9-dimethyl-9H-fluoren-2-yl)

H

3 C

H

3 C NNH

CH

3

CH

3 I To compound D3-1 (3.50 g, 6.91 mmol) dissolved in a mixture of toluene (10 mL) and 5 2-propanol (2 mL), phenylhydrazine (1.00 mL, 10.16 mmol) was added. The mixture was refluxed until the arylaldehyde D3-1 disappeared (TLC, v/v acetone/n-hexane, 1:4). After reaction was complete solvents were removed under reduced pressure. Yellow crystals of 20 (3.58 g, 87 %), formed upon adding the mixture of 2-propanol (15 mL) and toluene (4 mL), were filtered off and washed with 2-propanol. The crude 10 product was used in the next step without additional purification. c) 4-[Bis(9,9-dimethy-9H-fluoren-2-yl)amino]benzaldehyde-N-(4-formylphenyl)-N phenylhydrazone (D3-3; corresponds to compound 3 where both R equal 9,9-dimethyl 9H-fluoren-2-yl) H3C H3C NNN

CH

3

CH

3 15 A mixture of compound D3-2 (3.19 g, 5.36 mmol), 4-fluorobenzaldehyde (1.73 mL, 16.10 mmol) and K 2

CO

3 (4.45 g, 32.20 mmol) was refluxed in 25 mL anhydrous DMF under argon atmosphere for 16 h. After cooling to room temperature, 30 mL of distilled water were added and extraction was done with ethyl acetate. The organic layer was 20 washed with water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by column chromatography using 10:1:14 v/v toluene/ethyl acetate/n-hexane as an eluent to collect compound D3-3 as a yellow solid (2.10 g, 56 %). 25 1 H NMR (300 MHz, CDCl 3 , 6): 9.81 (s, 1 H, CHO), 7.73 (d, J = 9.0 Hz, 2H), 7.68 - 7.49 (m, 8H), 7.41 - 7.13 (m, 18H), 7.11 (d, J = 2.0 Hz, 1H), 7.08 (d, J = 2.0 Hz, 1H), 1.40 (s, 12H, CH3); WO 2014/006544 PCT/IB2013/055252 25 13 C NMR (75 MHz, CDCl 3 , 6): 190.68, 155.08, 153.47, 151.99, 148.83, 146.76, 138.86, 138.78, 138.36, 134.61, 131.36, 131.09, 129.85, 129.41, 128.85, 128.69, 127.72, 126.99, 126.60, 123.50, 123.03, 122.47, 120.63, 119.45, 118.96, 114.04, 46.81, 27.00; 5 IR (KBr): v = 3035 (aromatic CH); 2956, 2921, 2858, 2725 (aliphatic CH); 1689 (CHO); 1598, 1588, 1564, 1505, 1487 (C=C); 1157, 1117 (C-N); 867, 826 (CH=CH of 1,4 disubstituted benzene); 778, 758, 736 (CH=CH of monosubstituted benzene). Anal. calcd for C 5 oH 4 1

N

3 0 (%): C 85.81, H 5.90, N 6.00; found: C 85.70, H 5.94, N 6.03. 10 d) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde-N-4-(3-carboxymethyl-4 oxo-2-thioxo-1,3-thiazolidin-5-ylidenmethyl)phenyl-N-phenylhydrazone (D3)

H

3 C

H

3 C N S

CH

3 H0

CH

3 15 A mixture of compound D3-3 (0.70 g, 1.00 mmol), rhodanine-3-acetic acid (0.23 g, 1.2 mmol), and ammonium acetate (0.02 g, 0.29 mmol) was refluxed in acetic acid (7 mL) for 3.5 h. Afterwards, 20 mL of water was added and the extraction was done with ethyl acetate. The organic layer was washed with distilled water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by 20 column chromatography using toluene followed by 23:2 v/v toluene/methanol as an eluent to collect dye D3 as a dark red solid (0.58 g, 67 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.96 - 6.85 (m, 30H), 4.90 (s, 2H, CH 2 ), 1.46 (s, 12H, CH3); 25 13 C NMR (75 MHz, CDCl 3 , 6): 192.61, 171.46, 167.44, 155.34, 155.08, 153.59, 153.47, 146.70, 145.56, 138.79, 138.51, 134.55, 132.66, 131.04, 129.71, 129.34, 128.99, 128.18, 127.71, 126.99, 126.60, 125.27, 124.58, 123.50, 123.02, 122.47, 120.89, 120.64, 120.04, 119.71, 119.45, 118.96, 114.96, 46.88, 46.80, 26.99; 30 IR (KBr): v = 3545 (OH); 3034 (aromatic CH); 2956, 2920, 2858 (aliphatic CH); 1710 (C=O); 1574, 1504, 1488 (C=C); 1297 (C=S); 1198, 1175, 1135, 1104 (C-N); 868, 824 (CH=CH of 1,4-disubstituted benzene); 777, 757, 735 (CH=CH of monosubstituted benzene); WO 2014/006544 PCT/IB2013/055252 26 Anal. calcd. for C 55

H

4 4

N

4 0 3

S

2 (%): C 75.66, H 5.08, N 6.42; found: C 75.74, H 5.16, N 6.32. 5 Preparation of Dye D4 a) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde-N-phenyl-N propylhydrazone (D4-1; corresponds to compound 4 where both radicals R equal 9,9 dimethyl-9H-fluoren-2-yl) 10

H

3 C

H

3 C NN N

CH

3

CH

3

CH

3 To a refluxing mixture of compound 2 (3.05 g, 5.11 mmol; both radicals R equal 9,9 dimethyl-9H-fluoren-2-yl), 1-bromopropane (2.77 mL, 30.66 mmol) in anhydrous THF 15 (5 mL), powdered KOH (1.06 g, 18.89 mmol) and anhydrous Na 2

SO

4 (0.40 g, 2.81 mmol) were added in three equal portions every 1 h. After 3.5 hours the reaction mixture was extracted with ethyl acetate and distilled water until neutral. The organic layer was dried over anhydrous Na 2

SO

4 , filtered off and ethyl acetate was removed. The crude product was purified by column chromatography using 3:22 v/v acetone/n 20 hexane as an eluent to collect compound D4-1 as a yellow solid (3.01 g, 92 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.68 - 7.55 (m, 6H), 7.51 (s, 1 H), 7.42 - 7.05 (m, 16H), 6.89 (t, J = 6.9 Hz, 1 H), 3.86 (t, J = 7.7 Hz, 2H, CH 2

CH

2 CH3), 1.79 - 1.65 (m, 2H,

CH

2

CH

2 CH3), 1.41 (s, 12H, CH3), 1.03 (t, J = 7.3 Hz, 3H, CH 2

CH

2 CH3); 25 13 C NMR (75 MHz, CDCl 3 , 6): 155.02, 153.49, 147.51, 147.15, 138.93, 134.16, 131.20, 130.86, 129.03, 126.96, 126.86, 126.45, 123.84, 123.17, 122.45, 120.57, 120.02, 119.38, 118.59, 114.54, 46.88, 46.81, 27.02, 18.31, 11.37; 30 Anal. calcd for C 4 6

H

4 3

N

3 (%): C 86.62, H 6.79, N 6.59; found: C 86.70, H 6.69, N 6.61. b) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde-N-4-formylphenyl-N propylhydrazone (D4-2) WO 2014/006544 PCT/IB2013/055252 27

H

3 C

H

3 C N CH3

H

3

OH

3 lg c OH 3 Phosphorus oxychloride (1.06 mL, 11.60 mmol) was added drop wise to DMF (5.70 mL, 74.07 mmol) not allowing the temperature of the mixture to rise above 5 0 C. A solution of 22 (5.00 g, 7.84 mmol) in DMF (14.5 mL) was then added and the resulting 5 mixture was heated at 60 0 C for 50 min. The hot reaction mixture was poured into ice water, neutralized by adding sodium acetate (2.85 g, 34.80 mmol) aqueous solution, and extracted with ethyl acetate. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent was evaporated. Crude product was purified by column chromatography using 3:22 v/v acetone/hexane as an eluent to collect compound D4-2 10 as a yellow solid (1.16 g, 22 %). 1 H NMR (300 MHz, CDCl 3 , 6): 9.87 (s, 1 H, CHO), 7.85 (d, J = 8.9 Hz, 2H), 7.74 - 7.63 (m, 7H), 7.52 - 7.22 (m, 12H), 7.18 (d, J = 2.0 Hz, 1H), 7.15 (d, J = 2.0 Hz, 1H), 3.96 (t, J = 7.8 Hz, 2H, CH 2

CH

2 CH3), 1.87 - 1.72 (m, 2H, CH 2

CH

2 CH3), 1.47 (s, 12H, CH3), 15 1.12 (t, J = 7.3 Hz, 3H, CH 2

CH

2 CH3); 13 C NMR (75 MHz, CDCl 3 , 6): 190.61, 155.13, 153.52, 151.57, 148.64, 146.86, 138.83, 134.78, 134.60, 131.62, 129.56, 128.39, 127.55, 127.00, 126.60, 123.51, 123.22, 122.49, 120.64, 119.46, 118.96, 113.41, 46.84, 46.08, 27.02, 18.51, 11.28; 20 IR (KBr): v = 3747, 3186, 3035, 3010 (aromatic CH); 2957, 2921, 2858, 2724 (aliphatic CH); 1676 (CHO); 1595, 1565,1505,1486 (C=C); 1163, 1109 (C-N); 826 (CH=CH of 1,4-disubstituted benzene); 25 Anal. calcd. for C 47

H

43

N

3 0 (%): C 84.78, H 6.51, N 6.31; found: C 84.82, H 6.59, N 6.41. c) 4-[Bis(9,9-dimethyl-9H-fluoren-2-yl)amino]benzaldehyde-N-4-(3-carboxymethyl-4 oxo-2-thioxo-1,3-thiazolidin-5-ylidenmethyl)phenyl-N-propylhydrazone (D4) 30 WO 2014/006544 PCT/IB2013/055252 28

H

3 C

H

3 C CH3

CH

3 1 1I 9- CH 3 0 A mixture of 23 (0.58 g, 0.88 mmol) and rhodanine-3-acetic acid (0.20 g, 1.05 mmol) was refluxed in acetic acid (3.0 mL) for 2 h. Afterwards, water (15 mL) was added and the extraction was done with ethyl acetate. The organic layer was washed with distilled 5 water, dried over anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using toluene followed by 23:2 v/v toluene/methanol as an eluent to collect dye D4 as a dark red solid (0.43 g, 58 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.74 - 7.52 (m, 6H), 7.47 - 7.03 (m, 19H), 4.87 (s, 2H, 10 CH 2 ), 3.87 (t, J = 7.8 Hz, 2H, CH 2

CH

2 CH3), 1.78 - 1.65 (m, 2H, CH 2

CH

2 CH3), 1.41 (s, 12H, CH3), 1.04 (t, J = 7.3 Hz, 3H, CH 2

CH

2 CH3); 13 C NMR (75 MHz, CDCl 3 , 6): 192.58, 171.04, 167.31, 155.36, 155.08, 153.58, 146.82, 145.51, 138.81, 138.47, 136.02, 134.56, 132.89, 132.51, 128.98, 128.17, 126.99, 15 125.24, 124.60, 123.48, 122.53, 120.89, 120.64, 120.07, 119.71, 119.44, 118.93, 114.18, 46.89, 46.80, 44.65, 27.00, 18.49, 11.29; IR (KBr): v = 3635 (OH); 3032 (aromatic CH); 2957, 2921, 2859 (aliphatic CH); 1709 (C=O); 1602, 1573, 1505, 1486 (C=C); 1298 (C=S); 1182, 1100 (C-N); 823 (CH=CH of 20 1,4-disubstituted benzene); Anal. calcd. for C 52

H

4 6

N

4 0 3

S

2 (%): C 74.43, H 5.53, N 6.68; found: C 74.55, H 5.61, N 6.59. 25 Preparation of Dye D5 a) 4-(diphenylamino)benzaldehyde-N-phenylhydrazone (D5-1; corresponds to compound 2 where both radicals R equal phenyl) WO 2014/006544 PCT/IB2013/055252 29 N N N N Compound D5-1 was prepared according to Urnikaite S., Daskeviciene M., Malinauskas T., Jankauskas V., Getautis V., Monast. Chem., 2009, 140(12), 2005 2007. 5 b) 4-(diphenylamino)benzaldehyde-N-(4-formyl)phenyl-N-phenylhydrazone (D5-2; corresponds to compound 3 where both radicals R equal phenyl) 9 0 N N 6 10 A mixture of 1 (3.00 g, 8.25 mmol), 4-fluorobenzaldehyde (2.66 ml, 24.76 mmol) and

K

2

CO

3 (6.80 g, 49.52 mmol) was refluxed in 25 mL anhydrous DMF under argon atmosphere for 15 h. After cooling to room temperature, 30 mL of distilled water were added and extraction was done with ethyl acetate. The organic layer was washed with distilled water, dried over anhydrous sodium sulfate and filtered. After evaporation of 15 the solvent, the crude product was purified by column chromatography using 10:1:14 v/v toluene/ethyl acetate/hexane as an eluent to collect compound D5-2 as a yellow solid (1.98 g, 52%). 1 H NMR (300 MHz, CDCl 3 , 6): 9.80 (s, 1 H), 7.72 (d, J = 8.9 Hz, 2H), 7.68 - 7.58 (m, 20 2H),7.57 - 7.43 (m, 3H), 7.30 - 6.97 (m, 17H); 13 C NMR (75 MHz, CDCl 3 , 6): 190.68, 151.97, 148.65, 147.16, 138.80, 138.29, 131.33, 131.06, 129.81, 129.30, 128.97, 128.74, 128.61, 127.65, 124.76, 123.38, 122.69, 113.98; 25 IR (KBr): v (cm- 1 )= 3058, 3033 (aromatic CH); 2802, 2727, 2623 (aliphatic CH); 1688 (CHO); 1588,1563, 1505,1487 (C=C); 1157,1117 (C-N); 863, 826 (CH=CH of 1,4 disubstituted benzenes), 753, 738 (CH=CH of monosubstituted benzenes); 30 Anal. calcd. for C 32

H

2 5

N

3 0 (%): C 82.20, H 5.39, N 8.99; found: C 82.11, H 5.41, N 9.03.

WO 2014/006544 PCT/IB2013/055252 30 c) 4-(diphenylamino)benzaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo-1,3 thiazolidin-5-ylidenmethyl)phenyl-N-phenylhydrazone (D5) q N S N N N N I ~ .N., NO N N0 HO 5 A mixture of compound D5-2 (0.31 g, 0.67 mmol), rhodanine-3-acetic acid (0.15 g, 0.80 mmol) and ammonium acetate (0.015 g, 0.20 mmol) was refluxed in acetic acid (4.0 mL) for 4.5 h. Afterwards, 10 mL of water were added and the extraction was done with chloroform. The organic layer was washed with distilled water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by 10 column chromatography using 10:1:14 v/v toluene/ethyl acetate/hexane followed by 23:2 v/v toluene/methanol as an eluent to collect dye D5 as a dark red solid (0.28 g, 67%). 1 H NMR (300 MHz, 50% DMSO-d 6 /CDCl 3 , 6): 7.82 - 6.64 (m, 25H), 4.63 (s, 2H); 15 13 C NMR (75 MHz, 50% DMSO-d 6 /CDCl 3 , 6): 191.02, 165.29, 147.28,146.59, 145.22, 144.14, 136.20, 131.63, 131.05, 130.68, 129.48, 128.04, 127.72, 127.22, 126.96, 126.46, 126.03, 124.26, 122.95, 121.82, 120.65, 113.15, 44.93; 20 IR (KBr): v (cm- 1 )= 3614 (OH); 3032 (aromatic CH), 2924 (aliphatic CH); 1709 (C=O); 1575, 1504 (C=C); 1294 (C=S); 1198, 1175,1135,1104 (C-N); 823 (CH=CH of 1,4 disubstituted benzenes); 752, 723 (CH=CH of monosubstituted benzenes); Anal. calcd. for C 37

H

2 8

N

4 0 3

S

2 (%): C 69.35, H 4.40, N 8.74; found: C 69.28, H 4.42, N 25 8.77. Preparation of Dye D6 a) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-phenylhydrazone (D6-1; 30 corresponds to compound 2 where both radicals R equal 4-methylphenyl) WO 2014/006544 PCT/IB2013/055252 31

H

3 C N*NNH N

CH

3 To compound 1 (3.50 g, 6.91 mmol; both radicals R equal 4-methylphenyl) dissolved in toluene (10 mL) and 2-propanol (2 mL), phenylhydrazine (1.00 mL, 10.16mmol) was added. The mixture was refluxed until the compound 1 disappeared (TLC, acetone: n 5 hexane = 1:4). At the end of the reaction, the mixture was cooled to room temperature. Yellow crystals, having formed upon standing, were filtered off and washed with a mixture of 2-propanol and n-hexane (1:1) to give the corresponding compound D6-2 (4.03, 89%), which was used in the next reaction without further purification. 10 b) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-(4-formylphenyl)-N phenylhydrazone (D6-3; corresponds to compound 3 where both radicals R equal 4 methylphenyl)

H

3 C N - N N

CH

3 15 A mixture of D6-2 (3.27 g, 8.35 mmol), 4-fluorobenzaldehyde (2.69 ml, 25.07 mmol), and K 2

CO

3 (6.93 g, 50.14 mmol) were refluxed in anhydrous DMF (25 mL) under argon atmosphere for 24 h. After cooling to room temperature, distilled water (30 mL) was added and mixture was extracted with ethyl acetate, dried over anhydrous Na 2

SO

4 , filtered and solvent was evaporated. The crude product was purified by column 20 chromatography using 10:1:14 v/v toluene/ethyl acetate/n-hexane as an eluent to collect compound D6-3 as a yellow solid (2.76 g, 67 %). 1 H NMR (300 MHz, CDCl 3 , 6): 9.80 (s, 1 H, CHO), 7.72 (d, J = 8.9 Hz, 2H), 7.67 - 7.49 (m, 2H), 7.44 (d, J = 8.8 Hz, 2H), 7.27 - 6.93 (m, 16H), 2.31 (s, 6H, CH3); 25 13 C NMR (75 MHz, CDCl 3 , 6): 190.70, 152.04, 149.09, 144.65, 139.11, 138.35, 133.14, 131.97, 131.35, 131.04, 129.93, 129.84, 129.33, 127.57, 125.02, 121.42, 115.03, 113.93, 20.81; WO 2014/006544 PCT/IB2013/055252 32 IR (KBr): v = 3347, 3071, 3054 (aromatic CH); 2951, 2850, 2817, 2764 (aliphatic CH); 1685 (CHO); 1603, 1678, 1505, 1465 (C=C); 1169, 1157, 1112 (C-N); 875, 822 (CH=CH of 1,4-disubstituted benzenes), 796, 735 (CH=CH of monosubstituted benzene); 5 Anal. calcd for C 3 4

H

2 9

N

3 0 (%): C 82.40, H 5.90, N 8.48; found: C 82.31, H 5.95, N 8.53. c) 4-(4,4'-dimethyldiphenylamino)benzaldehyde-N-4-[3-(4-carboxy)phenyl-4-oxo-2 thioxo-1,3-thiazolidin-5-ylidenmethyl]phenyl-N-phenylhydrazone (D6) 10 S

H

3 C N N N/ N" N OOH

CH

3 A mixture of D6-3 (0.30 g, 0.61 mmol), 4-(4-oxo-2-thioxo-1,3-thiazolidin-3-yl)benzoic acid (0.18 g, 0.73 mmol) and ammonium acetate (0.017 g, 0.22 mmol) was refluxed in acetic acid (3.0 mL) for 6 h. At the end of the reaction, the mixture was cooled to room 15 temperature. The crystals formed upon standing were filtered off and washed with 2 propanol. The crude product was purified by column chromatography using 2:23 v/v methanol/toluene as an eluent to collect dye D6 as a dark red solid (0.196 g, 72%). 1 H NMR (300 MHz, CDCl 3 , 6): 8.25 (d, J = 8.4 Hz, 2H), 7.76 - 6.91 (m, 25H), 2.34 and 20 2.31 (two s of isomeric CH 3 , 6H); 13 C NMR (75 MHz, CDCl 3 , 6): 192.86, 170.61, 167.49, 149.54, 149.17, 144.67, 139.81, 139.20, 138.25, 134.78, 133.20, 132.68, 131.32, 131.07, 130.34, 129.96, 129.36, 128.83, 127.63, 126.20, 125.07, 121.43, 119.15, 117.45, 114.87, 20.94, 20.83; 25 IR (KBr): v = 3431 (OH); 3025 (aromatic CH); 2918, 2857 (aliphatic CH); 1698 (C=O); 1661, 1574, 1504, (C=C); 1294 (C=S); 1173, 1150 (C-N); 858, 815, 796 (CH=CH of 1,4-disubstituted benzenes); 754, 728, 716, 697 (CH=CH of monosubstituted benzene); 30 Anal. calcd for C 4 4

H

3 4

N

4 0 3

S

2 (%): C 72.31, H 4.69, N 7.67; found: C 72.36, H 4.70, N 7.63. Preparation of Dye D7 35 WO 2014/006544 PCT/IB2013/055252 33 a) 4-(4-methyldiphenylamino)benzaldehyde-N-phenylhydrazone (D7-1; corresponds to compound 2 where one radical R equals phenyl and the other radical R 4 methylphenyl) H

H

3 C N 5 To 4-[(4-methyldiphenyl)amino]benzaldehyde (6 g, 20.88 mmol) dissolved in toluene (30 mL) and 2-propanol (5 mL), phenylhydrazine (3.00 mL, 31.32 mmol) was added. The mixture was refluxed until the arylaldehyde disappeared (TLC, acetone:n-hexane = 3:22). At the end of the reaction, the mixture was cooled to room temperature. Yellow crystals, having formed upon standing, were filtered off and washed with a mixture of 2 10 propanol and n-hexane (1:1) to give the corresponding phenylhydrazone D7-1 (6.26, 80%), which was used in the next reaction without further purification. b) 4-(4-methyldiphenylamino)benzaldehyde-N-(4-formyl)phenyl-N-phenylhydrazone (D7-2)

H

3 C N NNN O 15 A mixture of compound D7-1 (2.65 g, 7.02 mmol), 4-fluorobenzaldehyde (1.63 mL, 15.19 mmol) and K 2

CO

3 (4.0 g, 28.94 mmol) was refluxed in 20 mL anhydrous DMF under argon atmosphere for 12 h. After cooling to room temperature, 40 mL of distilled water were added and extraction was done with ethyl acetate. The organic layer was 20 washed with water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by column chromatography using 1:24 v/v acetone/n-hexane as an eluent to collect compound D7-2 as a yellow solid (2.35 g, 70 %). 25 1 H NMR (300 MHz, CDCl 3 , 6): 9.80 (s, 1 H, CHO), 7.72 (d, J = 8.9 Hz, 2H), 7.68 - 7.49 (m, 3H), 7.46 (d, J = 8.7 Hz, 2H), 7.29 - 6.93 (m, 16H), 2.31 (s, 3H); WO 2014/006544 PCT/IB2013/055252 34 13 C NMR (75 MHz, CDCl 3 , 6): 190.65, 152.02, 148.87, 147.29, 144.56, 138.97, 138.37, 133.46, 131.33, 131.05, 130.01, 129.83, 129.35, 129.22, 128.60, 128.30, 127.62, 125.37, 124.39, 123.06, 122.10, 113.09, 20.84; 5 IR (KBr): v = 3034 (aromatic CH); 2921, 2804, 2728, 2627 (aliphatic CH); 1688 (C=O); 1599, 1588, 1562, 1505, 1489 (C=C); 1157, 1116, 1097 (C-N); 824, 797 (CH=CH of 1,4-disubstituted benzenes); 754,735, 725, 698 (CH=CH of monosubstituted benzenes); 10 Anal. calcd for for C 3 3

H

2 7

N

3 0 (%): C 82.30, H 5.65, N 8.73; found: C 82.33, H 5.71, N 8.83. c) 4-(4-methyldiphenylamino)benzaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo-1,3 thiazolidin-5-ylidenmethyl)phenyl-N-phenylhydrazone (D7) S

H

3 C NN NN NS 0 0 15 A mixture of D7-2 (1.20 g, 2.49 mmol), rhodanine-3-acetic acid (0.57 g, 2.99 mmol), and ammonium acetate (0.06 g, 0.75 mmol) was refluxed in acetic acid (15 mL) for 3.5 h. Afterwards, water (40 mL) was added and the extraction was done with ethyl acetate. The organic layer was washed with water, dried over anhydrous Na 2

SO

4 and 20 filtered. After evaporation of the solvent, the crude product was purified by column chromatography using 23:2 v/v toluene/methanol as an eluent to collect dye D7 as a dark red solid (0.45 g, 28%). 1 H NMR (300 MHz, 50% DMSO-d 6 /CDCl 3 , 6): 7.84 - 6.74 (m, 24H), 4.62 (s, 2H), 2.32 25 and 2.29 (two s of isomeric CH 3 , 3H); IR (KBr): v = 3481 (OH); 3026 (aromatic CH); 2920, 2853, 2604 (aliphatic CH); 1706 (C=O); 1591, 1577, 1504, 1491 (C=C); 1293 (C=S); 1175, 1136, 1105 (C-N); 863, 824, 779 (CH=CH of 1,4-disubstituted benzenes); 750, 696 (CH=CH of monosubstituted 30 benzenes); Anal. calcd for for C 3 8

H

3 0

N

4 0 3

S

2 (%): C 69.70, H 4.62, N 8.56; found: C 69.68, H 4.60, N 8.66.

WO 2014/006544 PCT/IB2013/055252 35 A2) Preparation of dyes D8 and D9 Similar to the preparation of dyes D1 to D7, condensation of dialdehydes with the corresponding hydrazine derivatives yielded dihydrazones, which were used in 5 arylation (with 4-fluorobenzaldehyde) or alkylation (with 1- bromononane) reactions and the resulting alkylated intermediate was subjected to a Vilsmeier-Haack reaction and the mono-formylated dihydrazone was isolated. Finally, condensation of the obtained aldehydes with rhodanine-3-acetic acid yielded dyes ID-1 370 (D8) and ID-1 492 (D9). 10 The detailed synthetic procedures are as follows: Preparation of Dye D8 a) 4-(4-formyl-4'-methyldiphenylamino)benzaldehyde (D8-1) 15 O N

CH

3 Compound D8-1 was prepared according to Getautis V., Daskeviciene M., Malinauskas T., Stanisauskaite A., Stumbraite J., Molecules 2006, 11, 64-71. 20 b) 4-(4-formyl-4'-methyldiphenylamino)benzaldehyde bis (N-phenylhydrazone) (D8-2) HH N

CH

3 To compound D8-1 (2.76 g, 8.75 mmol), dissolved in tetrahydrofuran (8 mL) and 2 propanol (22 mL), phenylhydrazine (2.15 mL, 21.88 mmol) was added. The mixture 25 was refluxed until the aldehyde disappeared. After completion of the reaction, the mixture was cooled to room temperature and crystals having formed upon standing were filtered off and washed with 2-propanol to give compound D8-2 (4.03 g, 93%), which was used in the next step without further purification.

WO 2014/006544 PCT/IB2013/055252 36 b) 4-(4-formyl-4'-methyldiphenylamino)benzaldehyde bis [N-(4-formyl)phenyl-N phenylhydrazone] (D8-3) 0N N N N N

CH

3 A mixture of D8-2 (2.80 g, 5.65 mmol), 4-fluorobenzaldehyde (1.82 mL, 16.95 mmol) 5 and K 2

CO

3 (4.68 g, 33.89 mmol) was refluxed in 21 mL anhydrous DMF under argon atmosphere for 20 h. After cooling to room temperature, 30 mL of distilled water were added and extraction was done with ethyl acetate. The organic layer was washed with water, dried over anhydrous Na 2

SO

4 and filtered. After evaporation of the solvent, the crude product was purified by column chromatography using 3:3:19 v/v acetone/diethyl 10 ether/n-hexane as an eluent to collect 13 as a yellow solid (1.39 g, 35 %). 1 H NMR (300 MHz, CDCl 3 , 6): 9.80 (s, 2H), 7.78 - 7.38 (m, 14H), 7.30 - 6.93 (m, 18H); 13 C NMR (75 MHz, CDCl 3 , 6): 151.94, 148.13, 144.06, 138.63, 138.27, 134.06, 131.33, 15 131.08, 130.14, 129.79, 129.41, 129.22, 128.68, 127.68, 125.66, 123.10, 114.03, 20.87; Anal. calcd for C 4 7

H

3 7

N

5 0 2 (%): C 80.21, H 5.30, N 9.95; found: C 80.19, H 5.43, N 9.92. 20 c) 4-(4-formyl-4'-methyldiphenylamino)benzaldehyde bis [N-4-(3-carboxymethyl-4-oxo 2-thioxo-1,3-thiazolidin-5-ylidenmethyl)phenyl-N-phenylhydrazone] (D8) S 9 9 N N a N N N 0 0 0 0 0 CH3 25 A mixture of D8-3 (0.95 g, 1.35 mmol), rhodanine-3-acetic acid (0.62 g, 2.19 mmol) and ammonium acetate (0.06 g, 0.81 mmol) was refluxed in acetic acid (20 mL) for 22 h.

WO 2014/006544 PCT/IB2013/055252 37 Afterwards, water (30 mL) was added and the extraction was done with toluene. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using 7:18 v/v acetone/n hexane followed by 3:22 v/v toluene/methanol as an eluent to collect dye D8 as a dark 5 red solid (0.26 g, 19 %). 1 H NMR (300 MHz, 50% DMSO-de/CDCl3): E = 8.13 - 6.72 (m, 34H), 4.70 (s, 4H), 2.31 (s, 3H); 10 Anal. calcd for C 5 7

H

4 3

N

7 0 6

S

4 (%): C 65.19, H 4.13, N 9.34; found: C 65.11, H 4.15, N 9.33. Preparation of Dye D9 15 a) 4-(4-formyldiphenylamino)benzaldehyde bis (N-phenylhydrazone) (D9-1) H H NN To D8-1 (11.55 g, 38.32 mmol), dissolved in toluene (50 mL), phenylhydrazine (9.0 mL, 91.97 mmol) was added. The mixture was refluxed until the aldehyde disappeared 20 (TLC, acetone:n-hexane = 7:18). At the end of the reaction, the mixture was cooled to room temperature. The crystals having formed upon standing were filtered off and washed with 2-propanol to give compound D9-1 (15.0 g, 82%), which was used in the next reaction without further purification. 25 b) 4-(4-formyldiphenylamino)benzaldehyde bis (N-nonyl-N-phenylhydrazone) (D9-2) N N N N N H3C CH3 To a refluxing mixture of compound D9-1 (5.0 g, 10.38 mmol), 1-bromononane (15.0 mL, 78.78 mmol) in anhydrous THF (30 mL), powdered KOH (1.92 g, 34.22 mmol) and WO 2014/006544 PCT/IB2013/055252 38 anhydrous Na 2

SO

4 (0.60 g, 4.22 mmol) were added in three equal portions every 1 h. After 19 hours the reaction mixture was extracted with ethyl acetate and distilled water until neutral. The organic layer was dried over anhydrous Na 2

SO

4 , filtered off and ethyl acetate was removed. The crude product was purified by column chromatography 5 using n-hexane to collect unreacted 1-bromononane, followed by 3:22 v/v toluene/n hexane as an eluent to collect compound D9-2 as a yellow solid (6.72 g, 88 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.58 (d, J = 8.7 Hz, 4H), 7.48 (s, 2H, N=CH), 7.39 - 7.19 (m, 1OH), 7.18 - 7.07 (m, 6H), 7.07 - 7.00 (m, 1H), 6.93 - 6.84 (m, 2H),3.88 (t, J = 7.5 10 Hz, 4H), 1.75 - 1.59 (m, 4H), 1.49 - 1.18 (m, 24H), 0.88 (t, J = 6.5 Hz, 6H, CH 2 CH3); 13 C NMR (75 MHz, CDCl 3 , 6): 147.31, 147.18, 147.06, 131.48, 130.68, 129.28, 129.03, 126.86, 124.56, 123.96, 123.14, 119.98, 114.50, 45.23, 31.83, 29.53, 29.41, 29.23, 27.08, 24.81, 22.64, 14.09; 15 elemental analysis calcd (%) for C 5 oH 63

N

5 : C 81.81, H 8.65, N 9.54; found: C 81.89, H 8.72, N 9.55. c) 4-[(N-nonyl-N-phenylhydrazin-2-ylmethyl)diphenylamino]benzaldehyde-N-(4 20 formyl)phenyl-N-nonylhydrazone (D9-3) CHs NN N" H, Phosphorus oxychloride (0.47 mL, 5.07 mmol) was added dropwise to DMF (2.85 mL, 37.03 mmol), not allowing the temperature of the mixture to rise above 5 'C. A solution 25 of D9-2 (2.48 g, 3.38 mmol) in DMF (6.0 mL) was added and the resulting mixture was heated at 60 'C for 2 h. The hot reaction mixture was poured into the ice water, neutralized by addition of sodium acetate (1.25 g, 15.23 mmol) aqueous solution, and extracted with ethyl acetate. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and the solvent evaporated. The crude product was purified by column 30 chromatography using 3:22 v/v diethyl ether/n-hexane as an eluent to collect compound D9-3 as a yellow solid (0.21 g, 9 %).

WO 2014/006544 PCT/IB2013/055252 39 1 H NMR (300 MHz, CDCl 3 , 6): 9.83 (s, 1 H), 7.80 (d, J = 8.9 Hz, 2H), 7.68 - 7.53 (m, 5H), 7.48 (s, 1 H), 7.42 (d, J = 8.9 Hz, 2H), 7.38 - 7.22 (m, 6H), 7.19 - 7.01 (m, 7H), 6.94 - 6.85 (m, 1 H), 4.01 - 3.79 (m, 4H), 1.76 - 1.59 (m, 4H), 1.52 - 1.15 (m, 24 H), 0.88 (t, J = 6.5 Hz, 6H); 5 13 C NMR (75 MHz, CDCl 3 , 6): 190.65, 151.48, 148.14, 147.13, 147.07, 146.73, 134.42, 131.93, 131.64, 130.50, 129.84, 129.38, 129.04, 128.32, 127.49, 126.91, 124.89, 124.38, 123.55, 123.27, 120.06, 114.52, 113.36, 45.25, 44.45, 31.83, 29.52, 29.48, 29.41, 29.35, 29.23, 29.20, 27.08, 26.98, 24.97, 24.79, 22.63, 14.09; 10 Anal. calcd for C 51

H

63

N

5 0 (%): C 80.38, H 8.33, N 9.19; found: C 80.40, H 8.17, N 9.11. d) 4-[ (N-nonyl-N-phenylhydrazin-2-ylmethyl)diphenylamino]benzaldehyde-N-4-(3 15 carboxymethyl-4-oxo-2-thioxo-1, 3-thiazolidin-5-yl idenmethyl)phenyl-N-nonyl hydrazone (D9) CH3 N N N N 0 0 H3C A mixture of D9-3 (0.16 g, 0.21 mmol), rhodanine-3-acetic acid (0.05 g, 0.25 mmol) and ammonium acetate (0.05 g, 0.06 mmol) was refluxed in acetic acid (3.5 mL) for 3 h. 20 Afterwards, water (15 mL) was added and the extraction was done with ethyl acetate. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using 1:24 v/v methanol/toluene as an eluent to collect dye D9 as a dark red solid (0.08 g, 41 %). 25 1 H NMR (300 MHz, CDCl 3 , 6): 7.72 - 6.73 (m, 25H), 4.82 (s, 2H), 3.96 - 3.69 (m, 4H), 1.74 - 1.49 (m, 4H), 1.44 - 1.07 (m, 24H), 0.93 - 0.71 (m, 6H); 13 C NMR (75 MHz, CDCl 3 , 6): 192.84, 187.16, 176.62, 165.24, 147.08, 134.05, 133.45, 130.09, 129.65, 129.38, 129.04, 127.60, 127.38, 127.07, 126.91, 126.04, 124.89, 30 124.34, 120.07, 114.53, 114.13, 45.25, 31.83, 29.53, 29.41, 29.23, 27.08, 24.81, 22.64, 14.10; WO 2014/006544 PCT/IB2013/055252 40 IR (KBr): v = 3481 (OH); 3059, 3030 (aromatic CH); 2951, 2923, 2851 (aliphatic CH); 1708 (C=O); 1577, 1505,1495 (C=C); 1284 (C=S); 1201, 1187, 1179, 1121, 1103 (C N); 892, 823 (CH=CH of 1,4-disubstituted benzenes), 747, 722, 693 (CH=CH of mono substituted benzenes); 5 Anal. calcd for C 56

H

66

N

6 0 3

S

2 (%): C 71.91, H 7.11, N 8.99; found: C 71.83, H 6.98, N 8.84. A3) Preparation of dyes D10 to D12 10 Preparation of Dye D10 a) 4-(diphenylamino)benzaldehyde-N-(7-chloroquinolin-4-yl)hydrazone (D10-1) CI NN N 15 To 4-(diphenylamino)benzaldehyde (1.0 g, 3.66 mmol; corresponds to compound 1 where both radicals R equal phenyl), dissolved in toluene (15 mL), 7-chloro-4 hydrazinoquinoline (1.0 g, 5.16 mmol), dissolved in methanol (30 ml), was added. The mixture was refluxed until the arylaldehyde disappeared (TLC, acetone:n-hexane = 20 7:18). Afterwards, the mixture was cooled to room temperature. Yellow crystals of 9 (1.41 g, 86%), having formed upon standing, were filtered off and washed with a mixture of 2-propanol and n-hexane (1:2). The crude product was used in the next step without additional purification. 25 b) 4-(diphenylamino)benzaldehyde-N-(4-formyl)phenyl-N-(7-chloroquinolin-4 yl)hydrazone (D10-2) N

NO

WO 2014/006544 PCT/IB2013/055252 41 A mixture of D10-1 (1.41 g, 3.15 mmol), 4-fluorobenzaldehyde (1.0 mL, 9.32 mmol) and

K

2

CO

3 (2.60 g, 18.81 mmol) was refluxed in 20 mL anhydrous DMF under argon atmosphere for 1.5 h. Afterwards, the mixture was cooled to room temperature, water (30 mL) was added and the extraction was done with chloroform. The organic layer 5 was washed with water, dried over anhydrous Na 2

SO

4 and filtered. Light orange crystals, having formed after evaporation of the solvent, were filtered off and washed with 2-propanol to give the corresponding arylaldehyde D10-2 (1.13 g, 65%). 1 H NMR (300 MHz, CDCl3): 6 = 10.09 (s, 1H, CHO), 8.54 - 8.47 (m, 2H), 8.08 (d, J = 10 8.5 Hz, 2H), 7.68 (d, J = 8.7 Hz, 2H), 7.56 (d, J = 8.3 Hz, 2H), 7.32 - 7.00 (m, 14H), 6.96 (d, J = 8.1 Hz, 1H), 6.82 (d, J = 1.9 Hz, 1H); 13 C NMR (75 MHz, CDCl3): 6 = 190.52, 155.46, 154.81, 149.37, 147.12, 146.38, 139.98, 136.44, 136.07, 131.67, 129.32, 129.13, 128.82, 128.15, 126.70, 125.01, 15 124.37, 123.52, 122.20, 121.13, 115.43, 101.72; IR (KBr): v = 3065 (aromatic CH); 2957, 2915, 2845, 2742 (aliphatic CH); 1697 (C=O); 1626,1594,1492,1436,1399(C=C);1187,1174,1143,1117,1105,1078 (C-N); 857, 837, 805 (CH=CH of 1,4-disubstituted benzenes); 751, 727, 711, 694 (CH=CH of 20 monosubstituted benzenes); Anal. calcd for C 3 5

H

2 5

CIN

4 0 (%): C 76.01, H 4.56, N 10.13; found: C 75.98, H 4.53, N 10.11. 25 c) 4-(diphenylamino)benzaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo-1,3 thiazolidin-5-ylidenmethyl)phenyl-N-(7-chloro-4-quinolin-4-yl)hydrazone (D10) CI N NINI NO -o N- _ 0 0 A mixture of D10-2 (0.4 g, 0.72 mmol), rhodanine-3-acetic acid (0.17 g, 0.87 mmol), 30 and ammonium acetate (0.02 g, 0.22 mmol) was refluxed in acetic acid (3 mL) for 50 min. At the end of the reaction, the mixture was cooled to room temperature. Dark orange crystals, having formed upon standing, were filtered off and washed with water, methanol and finally with diethyl ether to give dye D10 (0.4 g, 76%).

WO 2014/006544 PCT/IB2013/055252 42 1 H NMR (300 MHz, 50% DMSO-de/CDCl3): 6 = 8.53 - 8.39 (m, 2H), 7.97 (s, 1 H), 7.89 (d, J = 8.1 Hz, 2H), 7.80 -7.58 (m, 4H), 7.55 - 7.24 (m, 6H), 7.23 - 7.01 (m, 7H), 6.97 (d, J = 8.4 Hz, 2H), 6.87 (s, 1H), 4.75 (s, 2H); 5 IR (KBr): v = 3408 (OH); 3060, 3034 (aromatic CH); 2923 (aliphatic CH); 1715 (C=O); 1617, 1589, 1523, 1505, 1490 (C=C); 1291 (C=S); 1197, 1176, 1123, 1101, 1076 (C N); 895, 857, 823 (CH=CH of 1,4-disubstituted benzenes); 753, 729, 696 (CH=CH of monosubstituted benzenes); 10 Anal. calcd for C 4 0

H

2 8

CIN

5

O

3

S

2 (%): C 66.15, H 3.89, N 9.64; found: C 66.21, H 3.90, N 9.71. Preparation of Dye D11 15 a) 1 -Phenyl-3-propoxy-1,2,3,4-tetrahydroquinoline-6-carbaldehyde (D1 1-1)

H

3 C Compound D11-1 was prepared according to T. Malinauskas, J. Stumbraite, V. Getautis, V. Gaidelis, V. Jankauskas, G. Juska, K. Arlauskas, K. Kazlauskas Dyes and 20 Pigments 81 (2009) 131-136. b) 1-Phenyl-3-propoxy-1,2,3,4-tetrahydroquinoline-6-carbaldehyde-N-phenylhydrazone (D1 1-2) NH 25 To compound D11-2 (5.00 g, 17.77 mmol) dissolved in 2-propanol (25 mL), phenylhydrazine (2.31 mL, 21.31 mmol) was added. The mixture was refluxed for 1 h until the arylaldehyde disappeared (TLC, v/v diethylether/n-hexane, 2:3). At the end of the reaction, the mixture was cooled to room temperature. Yellow crystals, having WO 2014/006544 PCT/IB2013/055252 43 formed upon standing, were filtered off and washed with a mixture of 2-propanol and n hexane (1:2) to give the corresponding phenylhydrazone 25 (6.5 g, 99%), which was used in the next reaction without further purification. 5 c) 1 -Phenyl-3-propoxy-1,2,3,4-tetrahydroquinoline-6-carbaldehyde -N-(4-formyl)phenyl N-phenyl-hydrazone (D1 1-3) H 3 A mixture of compound D11-2 (6.5 g, 16.86 mmol), 4-fluorobenzaldehyde (3.14 g, 25.29 mmol), and K 2

CO

3 (6.99 g, 50.58 mmol) were refluxed in anhydrous DMF (35 10 mL) under argon atmosphere for 20 h. After cooling to room temperature, distilled water (30 mL) was added and mixture was extracted with ethyl acetate, dried over anhydrous Na 2

SO

4 , filtered and solvent was evaporated. The crude product was purified by column chromatography using 2:23 v/v acetone/n-hexane as an eluent to collect compound D11-3 as a yellow solid (5.28 g, 64 %). 15 1 H NMR (300 MHz, CDCl 3 , 6): 9.80 (s, 1H), 7.72 (d, J = 9.0 Hz, 2H), 7.62 (t, J = 7.4 Hz, 2H), 7.52 (t, J = 7.4 Hz, 1 H), 7.41 - 7.31 (m, 3H), 7.28 - 7.09 (m, 9H), 6.68 (d, J = 8.6 Hz, 1 H), 3.98 - 3.86 (m, 1 H), 3.83 - 3.73 (m, 1 H), 3.61 - 3.39 (m, 3H), 3.15 (dd, J = 15.7, 4.6 Hz, 1H), 2.89 (dd, J = 15.9, 7.9 Hz, 1H), 1.65 - 1.50 (m, 2H), 0.89 (t, J = 7.4 20 Hz, 3H); 13 C NMR (75 MHz, CDCl 3 , 6): 190.89, 152.38, 147.35, 145.22, 140.12, 138.77, 131.58, 131.21, 130.14, 129.72, 129.43, 128.79, 128.55, 125.86, 125.60, 125.13, 124.63, 122.17, 115.10, 114.07, 71.33, 70.60, 54.17, 34.40, 23.39, 10.78; 25 Anal. calcd. for C 32

H

3 1

N

3 0 2 (%): C 78.50, H 6.38, N 8.58; found: C 78.41, H 6.52, N 8.63. d) 1-Phenyl-3-propoxy-1,2,3,4-tetrahydroquinoline-6-carbaldehyde-N-4-(3 30 carboxymethyl-4-oxo-2-thioxo-1,3-thiazolidin-5-ylidenmethyl)phenyl-N phenylhydrazone (D1 1) WO 2014/006544 PCT/IB2013/055252 44 S N S COOH

H

3 C N A mixture of compound D11-3 (0.99 g, 2.03 mmol), rhodanine-3-acetic acid (0.46 g, 2.43 mmol) and ammonium acetate (0.05 g, 0.61 mmol) was refluxed in acetic acid (3.0 mL) for 2 h. Afterwards, water (15 mL) was added and the extraction was done with 5 chloroform. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using 2:23 v/v methanol/toluene as an eluent to collect dye D11 as a dark red solid (0.81 g, 61 %). 1 H NMR (300 MHz, CDCl 3 , 6): 7.82 - 7.05 (m, 17H), 6.72 (dd, J = 8.5, 6.2 Hz, 1 H), 6.41 10 (d, J = 8.9 Hz, 1 H), 4.89 (s, 2H), 4.04 - 3.89 (m, 1 H), 3.89 - 3.41 (m, 4H), 3.27 - 2.84 (m, 2H), 1.71 - 1.52 (m, 2H), 1.03 - 0.83 (m, 3H); Anal. calcd for C 3 7

H

3 4

N

4 0 4

S

2 (%): C 67.05, H 5.17, N 8.45; found: C 67.17, H 5.31, N 8.58. 15 Preparation of Dye D12 a) 1,2,3,3a,4,8b-hexahydro-4-[4-(2,2-diphenylethenyl)phenyl]cyclopenta[b]indole-7 carboxaldehyde (D12-1) 0 N 20 Prepared according to published Japanese patent application JP 2010-083767. b) 1,2,3,3a,4,8b-hexahydro-4-[4-(2,2-diphenylethenyl)phenyl]cyclopenta[b]indole-7 carboxaldehyde-N-phenylhydrazone (D12-2) WO 2014/006544 PCT/IB2013/055252 45 NH \ \ N To compound D12-1 (1.50 g, 3.39 mmol) dissolved in toluene (8 mL) and 2-propanol (4 mL), phenylhydrazine (0.40 mL, 4.08 mmol) was added. The mixture was refluxed for 2.5 h until the arylaldehyde disappeared (TLC, toluene). At the end of the reaction, the 5 mixture was cooled to room temperature. Yellow crystals, having formed upon standing, were filtered off and washed with 2-propanol to give the corresponding phenylhydrazone D12-2 (1.42 g, 79%), which was used in the next reaction without further purification. 10 c) 1,2,3,3a,4,8b-hexahydro-4-[4-(2,2-diphenylethenyl)phenyl]cyclopenta[b]indole-7 carboxaldehyde-N-(4-formyl)phenyl-N-phenylhydrazone (D12-3) N A mixture of compound D12-2 (1.3 g, 2.45 mmol), 4-fluorobenzaldehyde (0.45 g, 3.7 mmol), and K 2

CO

3 (1.02 g, 7.34 mmol) were refluxed in anhydrous DMF (25 mL) under 15 argon atmosphere for 5 h (TLC, toluene). After cooling to room temperature, distilled water (30 mL) was added and mixture was extracted with ethyl acetate, dried over anhydrous Na 2

SO

4 , filtered and solvent was evaporated. The crude product was purified by column chromatography using 2:2:21 v/v acetone/THF/n-hexane as an eluent to collect compound D12-3 as a yellow solid (0.86 g, 55 %). 20 1 H NMR (300 MHz, CDCl 3 , 6): 9.98 (s, 1H), 7.93 (d, J = 8.7 Hz, 2H), 7.74 (d, J = 8.9 Hz, 2H), 7.64 (t, J = 7.4 Hz, 2H), 7.60 - 7.50 (m, 2H), 7.50 - 7.12 (m, 16 H), 7.11 - 6.88 (m, 4H), 4.86 - 4.66 (m, 1 H), 3.96 - 3.70 (m, 1 H), 2.15 - 1.36 (m, 6H); 25 13 C NMR (75 MHz, CDCl 3 , 6): 190.87, 161.26, 152.46, 148.16, 143.81, 141.28, 140.97, 140.43, 138.88, 136.31, 132.85, 132.33, 131.67, 131.30, 130.96, 130.68, 130.62, 130.26, 129.52, 129.05, 128.62, 128.44, 128.03, 127.85, 127.63, 127.49, 126.44, 122.66, 119.63, 118.53, 114.15, 108.29, 69.10, 45.36, 35.12, 34.10, 24.63; WO 2014/006544 PCT/IB2013/055252 46 Anal. calcd. for C 4 5

H

3 7

N

3 0 (%): C 85.01, H 5.87, N 6.61; found: C 85.25, H 5.72, N 6.59. d) 1,2,3,3a,4,8b-hexahydro-4-[4-(2,2-diphenylethenyl)phenyl]cyclopenta[b]indole-7 5 carboxaldehyde-N-4-(3-carboxymethyl-4-oxo-2-thioxo-1,3-thiazolidin-5-yliden methyl)phenyl-N-phenylhydrazone (D12) COOH N S N / A mixture of compound D12-3 (0.205 g, 0.32 mmol), rhodanine-3-acetic acid (0.074 g, 0.39 mmol) and ammonium acetate (0.015 g, 0.19 mmol) was refluxed in acetic acid 10 (3.0 mL) for 6.5 h. Afterwards, water (15 mL) was added and the extraction was done with chloroform. The organic layer was dried over anhydrous Na 2

SO

4 , filtered, and solvent evaporated. The crude product was purified by column chromatography using 47:3 v/v toluene/methanol as an eluent to collect dye D12 as a dark red solid (0.125 g, 48 %). 15 1 H NMR (300 MHz, CDCl 3 , 6): 7.74 - 7.47 (m, 3H), 7.45 - 7.08 (m, 20H), 7.06 - 6.80 (m, 6H), 4.95 - 4.66 (m, 3H), 3.97 (dd, J = 7.5, 5.8 Hz, 1H), 2.14 - 1.71 (m, 6H); Anal. calcd. for C 5 oH 4 0

N

4 0 3

S

2 (%): C 74.23, H 4.98, N 6.93; found: C 74.50, H 5.11, N 20 6.69. B) Preparation and characterization of the DSCs General Methods and Materials 25 Preparation of the (solid-state) DSCs: A TiO 2 blocking layer was prepared on a fluorine doped tin oxide (FTO)-covered glass substrate using spray pyrolysis (cf. B. Peng, G. Jungmann, C. Jager, D. Haarer, H. W. Schmidt, M. Thelakkat, Coord. Chem. Rev. 2004, 248, 1479). Next, a TiO 2 paste (Dyesol), diluted with terpineol, was applied by 30 screen printing, resulting in a film thickness of 1.7 pm. All films were then sintered for 45 min at 450 'C, followed by treatment in a 40 mM aqueous solution of TiCl 4 at 60 'C for 30 min, followed by another sintering step. The prepared samples with TiO 2 layers WO 2014/006544 PCT/IB2013/055252 47 were pretreated with 5 mM solutions of the additives 2-(p-butoxyphenyl)acetohydro xamic acid ("ADD3"), 2-(p-butoxyphenyl)acetohydroxamic acid sodium salt ("ADD1") or 2-(p-butoxyphenyl)acetohydroxamic acid tetrabutylammonium salt ("ADD2") in ethanol (these additives are described on pages 52 and 53 of WO 2012/001628 Al as 5 "Example No. 5", "Example No. 6" and "Example No. 10", respectively). The electrodes were then dyed in 0.5 mM dye solution in CH 2 Cl 2 . Spiro-MeOTAD was applied by spin coating from a solution in DCM (200 mg/mL) also containing 20 mM Li(CF 3

SO

2

)

2 N. Fabrication of the device was completed by evaporation of 200 nm of silver as the counter electrode. The active area of the sDSC was defined by the size of these 10 contacts (0.13 cm 2 ), and the cells were masked by an aperture of the same area for measurements. The current-voltage characteristics for all cells were measured with a Keithley 2400 under 1000 W/m 2 , AM 1.5G conditions (LOT ORIEL 450 W). The incident photon to current conversion efficiency's (IPCE) were obtained with an Acton Research Monochromator using additional white background light illumination. 15 The samples were illuminated with monochromatic light from the quartz monochromator with deuterium lamp. The power of the incident light beam was (2 5).10-8 W. The negative voltage of -300 V was supplied to the sample substrate. The counter-electrode with the 4.5x15 mm 2 slit for illumination was placed at 8 mm distance 20 from the sample surface. The counter-electrode was connected to the input of the BK2 16 type electrometer, working in the open input regime, for the photocurrent measurement. The 10-15 - 10-12 A strong photocurrent was flowing in the circuit under illumination. The photocurrent J is strongly dependent on the incident light photon energy hv. The JO-5 = f(hv) dependence was plotted. Usually the dependence of the 25 photocurrent on incident light quanta energy is well described by linear relationship between JO-5 and hv near the threshold (cf. E. Miyamoto, Y. Yamaguchi, M. Yokoyama, Electrophotography 1989, 28, 364 and M. Cordona, L. Ley, Top. Apple. Phys. 1978, 26, 1). The linear part of this dependence was extrapolated to the hv axis and Jp value was determined as the photon energy at the interception point. 30 The results of the DSCs with varying dyes and additives are given in the following table 1.

WO 2014/006544 PCT/IB2013/055252 48 Table 1. Photovoltaic performance of sDSCs based on the D1-D12 dyes Dye Additive Jsc [mA cm- 2 ] Voc [mV] FF [%] r1 [%] D1 ADD1 7.34 680 51 2.5 D1 ADD3 6.86 560 57 2.2 D2 ADD1 7.82 760 62 3.7 D2 ADD2 6.9 580 55 2.2 D3 ADD1 7.00 800 64 3.6 D3 ADD2 8.04 660 58 3.1 D4 ADD1 6.51 840 64 3.5 D4 ADD2 7.28 840 62 3.8 D8 ADD1 2.76 740 56 1.1 D8 ADD2 3.42 780 58 1.5 D9 ADD1 5.3 800 74 3.1 D9 ADD2 4.18 760 69 2.2 D11 ADD1 6.08 780 68 3.2 D11 ADD2 6.9 720 66 3.3 D12 ADD1 7.68 680 61 3.2 D12 ADD2 7.71 740 63 3.6

Claims

1. Compounds of general formula 1 5 R 10R 200 D NN A - - m (I) wherein 10 R 100 and R 2 0 0 are each independently hydrogen, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, C 5 -C 7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl or aryloxy-Ci-Cio-alkyl, 15 D is an m-valent donor moiety which comprises at least one carbon-carbon or carbon-heteroatom double bond and/or at least one unfused or fused carbo- or heterocyclic ring, 20 A is an acceptor moiety which comprises at least one carbon-carbon or carbon-heteroatom double bond and/or at least one unfused or fused carbo or heterocyclic ring, 25 m takes values of 1, 2 or 3, and the donor moiety D and the acceptor moiety A are -rr-conjugated to one another. 30

2. Compounds according to claim 1, wherein in general formula I R100 is hydrogen or C 1 -C 4 -alkyl, 35 and R200 is aryl or Ci-Cio-alkyl which in case of C 2 -alkyl WO 2014/006544 PCT/IB2013/055252 50 may be interrupted by one and in case of C 3 -C 10 alkyl by one or two nonadjacent oxygen atoms.

3. Compounds according to claim 1 or claim 2, wherein the donor moiety D in 5 general formula I for m = 1: is selected from the group consisting of: R 10R 140 R 150 R14 1510R R R1 R 210 250 N25 N RR220/ R 220/ Z (D( ) (D02) (D03) R110 R 150 R14021 R10 R R \ R 0120 R R R 1 R 220 N 2 250 R 2 R R x 10 (D04) (D05) (D06) R 130 R 140 R 160 10 2 R50 \NC 10 R 1210 230 R 1 2 N 110 R N 110 2 N N N 1250 R 1250 R R 24 (D07) RD8)R (D09) R260 0 120 R 140 120 Z R 150O R1 R 0 n 110 ae N N 1250 R \ 250 \ N 5 (D )R(D1I1) (D12) R 10 110 R1 N adR 220 / N -813 (D 13) R120 13 (D14) and 15 R 1 1 0 , R 120 and R 130 are each independently hydrogen, halogen, WO 2014/006544 PCT/IB2013/055252 51 hydroxyl, C1-C1o-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 10 alkyl by one or two nonadjacent oxygen atoms, C 5 -C 7 -cycloalkyl, Ci-Cio-alkoxy, C 1 -C 10 5 alkylamino, di(Ci-Cio-alkyl)amino, C 1 -C 10 alkylamino- or di(C1-Cio alkyl)aminosulfonylamino, C 1 -C 10 alkylsulfonylamino, aryl, aryl-C1-Cio-alkyl, aryloxy-C1-C1o-alkyl or an -NHCOR 1 70 10 or -N HCOOR 1 70 radical, R 14 0 , R 150 and R 1 60 are each independently hydrogen, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two 15 nonadjacent oxygen atoms, C 5 -C 7 -cycloalkyl, aryl aryl-C1-C1o-alkyl, aryloxy-Ci-Cio-alkyl or in case R 140 and R 160 or R 150 and R 160 are bonded to adjacent carbon atoms these pairs of groups may -together with the carbon atoms to which 20 they are bonded- form a five- or six-membered ring in which one CH 2 group may be replaced by an oxygen atom, R170 is aryl, aryl-C1-C1o-alkyl, aryloxy-Ci-Cio-alkyl or 25 Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms and in case of two moities for m = 2 may vary independently of each other,, 30 R 2 1 0 , R 22 0 , R 2 3 0 and R 24 0 are each independently aryl, aryl-Ci-Cio-alkyl, aryloxy-C1-C1o-alkyl, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen 35 atoms, C 5 -C1o-cycloalkyl, or R 2 1 0 and R 2 20 and/or R 23 0 and R 2 4 0 form, together with the nitrogen atom to which they are bonded, a five- or six membered ring in which one CH 2 group not adjacent to the nitrogen atom may be replaced 40 by an oxygen atom, or in case NR 2 10 R 2 2 0 and R 11 0 are bonded to adjacent carbon atoms, R 11 0 and R 2 10 or R 11 0 and R 2 2 0 -together with the WO 2014/006544 PCT/IB2013/055252 52 nitrogen atom of the moiety NR 2 10 R 22 0 and the carbon atom to which the moieties NR 2 10 R 2 2 0 and R 11 0 are bonded- form a five- or six-membered ring in which one CH 2 group not adjacent to the 5 nitrogen atom may be replaced by an oxygen atom and which five- or six-membered ring may be fused to another five- or six-membered saturated or unsaturated ring, 10 R 250 and R 260 are each independently Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, C 5 -C 7 -cycloalkyl, aryl, aryl-Ci-Cio alkyl or aryloxy-C1-Cio-alkyl 15 and Z isO orS, 20 for m = 2: is selected from the group consisting of: R17 R 170 R 170 N N 0 N 170 H 3 C CH 3 R H 3 C CH 3 N N and \/' \// 25 where R 17 0 has the meaning given before and in case of two moities may vary independently of each other, 30 and for m= 3: is selected from the group consisting of: WO 2014/006544 PCT/IB2013/055252 53 0 | 1 17 H3C CH 3 N and N 5 where R 17 0 has the meaning given before.

4. Compounds according to claim 1 or claim 2, wherein the donor moiety D in general formula I 10 for m = 1: is selected from the group consisting of: R 10 R 150 140 R R 21 210R 1N0 R N210 N 220/ '- R 2 / R R 22/ sR220/ N-Z N (D01) (D02) (D03) (D06) R 13 o R11110 RR 1 0 NC* R R 210 N R 230 and R220/ I- N N N 1 R N110' R 2 120R 130 1250 R R (D09) R R 15 (D07) (D14) for m = 2: is selected from the group consisting of: WO 2014/006544 PCT/IB2013/055252 54 H 3 C CH 3 N N and and for m = 3: is selected from the group consisting of: N N and 5 and the variables have the aforementioned meaning.

5. Compounds according to claim 1 or claim 2, wherein the donor moiety D in 10 general formula I for m = 1: is a moiety: R 110 210 R\N / R220/ 15 (D01) and R110 is hydrogen, halogen, hydroxyl, Ci-Cio-alkyl 20 which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, C 5 -C 7 -cycloalkyl, C 1 C1o-alkoxy, C 1 -C 1 o-alkylamino, di(C1-C1o alkyl)amino, C 1 -C 1 o-alkylamino- or di(C1-C1o 25 alkyl)aminosulfonylamino, C 1 -C 1 o alkylsulfonylamino, aryl, aryl-Ci-Cio-alkyl, WO 2014/006544 PCT/IB2013/055252 55 aryloxy-C1-C1o-alkyl or an -NHCOR 1 70 or -N HCOOR 1 70 radical, R170 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or 5 Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, and 10 R 2 1 0 and R 2 2 0 are each independently aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl, Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen 15 atoms, C 5 -C1o-cycloalkyl, or R 2 1 0 and R 2 20 form, together with the nitrogen atom to which they are bonded, a five- or six-membered ring in which one CH 2 group not adjacent to the nitrogen atom may be replaced by an oxygen atom, or in case 20 NR 2 10 R 2 2 0 and R 11 0 are bonded to adjacent carbon atoms, R 11 0 and R 2 10 or R 11 0 and R 2 2 0 together with the nitrogen atom of the moiety NR 2 10 R 2 2 0 and the carbon atom to which the moieties NR 2 10 R 2 2 0 and R 11 0 are bonded- form a 25 five- or six-membered ring in which one CH 2 group not adjacent to the nitrogen atom may be replaced by an oxygen atom and which five- or six-membered ring may be fused to another five or six-membered saturated or unsaturated ring, 30 for m = 2: is selected from the group consisting of: 170 170 N N and 35 where R 17 0 has the meaning given before, and for m = 3: WO 2014/006544 PCT/IB2013/055252 56 is a moiety N 5

6. Compounds according to one or more of the preceding claims 1 to 5, wherein the acceptor moiety A in general formula I is a group of formula la: R340 A* (la) werein A* denotes a moiety selected from the group consisting of R310 CN N 'R1 R N R ON , O * 0 *4N-FR lO 0 N N N N/ 0 q\410 N 7 ~ 32 320 (AO1) (A02) (A03) R320 R (A04) RN 330 R330 N * 3N40 0 * N R 4 1 0 a n d Y R 10 (A05) (A06) (A07) (A08) and * indicates the position which the double bond of 15 the group of formula la is bonded to, R 3 1 0 and R 3 2 0 are each independently hydrogen, Ci-Cio-alkyl WO 2014/006544 PCT/IB2013/055252 57 which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, or C 5 -C 7 -cycloalkyl, 5 R330 is hydrogen, C1-Cio-alkyl which in case of C 2 alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, partly fluorinated C1-C1o-alkyl, perfluorinated C1-C1o-alkyl, C 5 -C 7 -cycloalkyl, aryl, 10 aryl-C1-C1o-alkyl or aryloxy-Ci-Cio-alkyl, R340 is hydrogen, NO 2 , CN, COR 3 50 , COOR 3 50 , S0 2 R 3 50 or S0 3 R 350 , 15 R 350 is aryl, aryl-C1-C1o-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, 20 R410 is hydrogen, C1-Cio-alkyl which in case of C 2 alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms and which may be mono- or polysub stituted by hydroxyl, mercapto, halogen, cyano, 25 nitro, -COOM and/or -COOR 420 , C 5 -C 7 -cycloalkyl, aryl, aryl-C1-C1o-alkyl, aryloxy-Ci-Cio-alkyl, or an -NHCOR 420 or -N(CO R 4 20 ) 2 radical where the two R 4 2 0 in the latter may be the same or different, 30 X is independently CH or N, Y is 0, C(CN) 2 , C(CN)(COOM) or C(CN)(COOR 420 ), 35 M is alkali metal cation or [NR 4 2 0 4 +, and 40 R420 is hydrogen, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci C 1 o-alkyl or C 1 -C 1 o-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 10 - WO 2014/006544 PCT/IB2013/055252 58 alkyl by one or two nonadjacent oxygen atoms.

7. Compounds according to one or more of the preceding claims 1 to 5, wherein the acceptor moiety A in general formula I is: 5 R 340 s N- 4 10 (AO1) and 10 R340 is hydrogen, NO 2 , CN, COR 3 50 , COOR 3 50 , S0 2 R 3 50 or S0 3 R 350 , R 350 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or Ci-Cio-alkyl which in case of C 2 -alkyl may be 15 interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, R410 is hydrogen, Ci-Cio-alkyl which in case of C 2 alkyl may be interrupted by one and in case of 20 C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms and which may be mono- or polysub stituted by hydroxyl, mercapto, halogen, cyano, nitro, -COOM and/or -COOR 420 , C 5 -C 7 -cycloalkyl, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl, or an 25 -NHCOR 420 or -N(CO R 420 ) 2 radical where the two R 420 in the latter may be the same or different, M is alkali metal cation or [NR 420 4 +, 30 and R420 is hydrogen, aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci C 1 o-alkyl or C 1 -C 1 o-alkyl which in case of C 2 -alkyl 35 may be interrupted by one and in case of C 3 -C 10 alkyl by one or two nonadjacent oxygen atoms.

8. Compounds according to one or more of the preceding claims 1 to 5, wherein the acceptor moiety A in general formula I is: WO 2014/006544 PCT/IB2013/055252 59 R 340 s N- 4 10 (AO1) and 5 R340 is hydrogen, NO 2 , CN, COR 3 50 , COOR 3 50 , S0 2 R 3 50 or S0 3 R 350 , R 350 is aryl, aryl-Ci-Cio-alkyl, aryloxy-Ci-Cio-alkyl or 10 Ci-Cio-alkyl which in case of C 2 -alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms, R410 is aryl or Ci-Cio-alkyl which in case of C 2 -alkyl 15 may be interrupted by one and in case of C 3 -C 10 alkyl by one or two nonadjacent oxygen atoms and which is terminally substituted by hydroxyl, COOM or -COOR 420 , 20 M is alkali metal cation or [NR 420 4 +, and R420 is hydrogen or Ci-Cio-alkyl which in case of C 2 25 alkyl may be interrupted by one and in case of C 3 -C 1 o-alkyl by one or two nonadjacent oxygen atoms.

9. Use of compounds of formula I according to one or more of the preceding claims 30 1 to 8 for producing dye-sensitized solar cells.

10. A dye-sensitized solar cell comprising compounds of formula I according to one or more of the preceding claims 1 to 8.