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Synthesis and near-infrared characteristics of novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores
Chinese Chemical Letters 18 (2007) 283–286 www.elsevier.com/locate/cclet
Synthesis and near-infrared characteristics of novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores Bo Gao, Yang Li, He Tian * Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, China Received 9 November 2006
Abstract Novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores have been prepared conveniently by coupling of 1,8-naphthalimide and dibromoperylene bisimides. Their optical properties were investigated by UV–vis and fluorescence spectroscopy. The absorption spectra of these compounds showed wide spectral responses from 300 to 700 nm, which would be potentials for application as organic solar cells. # 2007 He Tian. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Perylene bisimide; Naphthalimide; Near-infrared
Organic solar cells are promising candidates for renewable sources of electrical energy, due to the advantages of low production cost, lightweight and capability to make flexible devices in comparison with the traditional siliconbased solar cells [1–3]. One important factor that governs the performance of a solar cell, is the absorption spectrum of the organic semiconductors or the dye molecules used for device fabrication. In an ideal situation, the solar cell’s absorption spectrum should completely cover the region of solar irradiation. Therefore, the development of novel dye molecules with appropriate absorptive properties for photon harvesting has become an important area. Perylene and its derivatives, especially perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI) have shown great promise in a variety of applications owing to their outstanding photochemical and thermal stability [4]. In particular, PBI dyes show unusual photocurrent amplification properties and have potential for application in solar cells [5]. We previously reported the perylene bisimide derivatives containing piperidine groups and the absorption maximum of such dyes have obvious bathochromic shift relative to the precursor due to the electron-donating ability of amines [7]. However, the width of the absorption band was not significantly expanded. Naphthalimide derivatives are well known as brilliant greenish-yellow dyes and exhibit absorption maxima around 400 nm. They have excellent photochemical and thermal stability.
* Corresponding author. E-mail address: [email protected] (H. Tian). 1001-8417/$ – see front matter # 2007 He Tian. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2007.01.014
284
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286
Fig. 1. The chemical structures of compounds 1, 2 and 3.
Herein, we incorporated the naphthalimide chromophores at 1- and/or 7 bay positions of perylene bisimide for the first time via piperazidine units and synthesized compounds 1, 2 and 3 (Fig. 1). The multichromophoric perylene bisimide derivatives show wide spectral responses from 300 to 700 nm. Perylene bisimide derivatives were synthesized by the reaction of 1,8-naphthalimide with dibromoperylene bisimides in N-methyl-2-pyrrolidone (NMP) under dry argon. The reactions are very sensitive to change of temperature. At room temperature the reactions were very slow, and monosubstituted perylene bisimide 2 was the major product; at high temperatures (above 130 8C) the 1-bromine is replaced by a hydrogen atom and compound 1 was formed as the major products. Selective formation of the desired product 3 was made possible by careful adjustment of temperatures. Compounds 1, 2 and 3 were characterized by 1H NMR and mass spectra [6] (Fig. 1). The optical properties of perylene bisimide derivatives 1, 2 and 3 in CH2Cl2 were investigated by UV/Vis and fluorescence spectroscopy. The absorption spectra of compounds 1, 2 and 3 are shown in Fig. 2. All of these compounds are highly soluble in various organic solvents, such as CH2Cl2, CHCl3, toluene and acetone. Introduction of naphthalimide groups at the 1- and/or 7-positions of perylene bisimide core induced dramatic bathochromic shifts relative to the lowest energy optical transition of the Br-substituted PBIs (lmax = 526 nm in chloroform) [7]. Compound 1 shows intense absorption bands with maxima at 578 (e = 2.50 104 mol L 1 cm 1) and 394 nm (e = 2.25 104 mol L 1 cm 1), which can be attributed to the perylene bisimide and naphthalimide moieties. Compared with the parent chromophores, the absence of additional absorption bands indicated insignificant groundstate interaction between these two chromophores. Compound 2 exhibited similar absorption profile, but the absorption maxima of the chromophores are shifted to 597 (e = 2.23 104 mol L 1 cm 1) and 397 nm (e = 2.31 104 mol L 1 cm 1), respectively. Progressive red-shifts of the absorption maxima occurred when two naphthalimide chromophores were incorporated to the perylene bisimide core. The absorption maxima of compound 3 are shifted to 646 (e = 2.05 104 mol L 1 cm 1) and 397 nm (e = 3.02 104 mol L 1 cm 1). Compared with Brsubstituted PBI [7], the feature absorption of perylene bisimide fragments broadened obviously in compounds 1, 2 and 3 (the half-band width of compounds 1, 2 and 3 in long wavelength are 116, 120 and 130 nm, respectively), which
Fig. 2. Absorption spectra of compounds 1, 2 and 3 in CH2Cl2 (c = 1.0 10
5
mol L 1).
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286
285
Fig. 3. Fluorescence spectra of compounds 1, 2 and 3 in CH2Cl2 (c = 1.0 10 5 mol L 1; (1) compound 1, lex = 578 nm; (2) compound 1, lex = 394 nm; (3) compound 2, lex = 597 nm; (4) compound 2, lex = 397 nm; (5) compound 3, lex = 646 nm; (6) compound 3, lex = 397 nm).
could be attributed to the following reasons. One could be the increase of the p-conjugation between the substituents and the perylene bisimide core [8]. Another could be the twisting of the perylene bisimide core by the substituents, so that the vibronic structure is lost [9]. Fig. 3 showed the fluorescence spectra of compounds 1, 2 and 3 in CH2Cl2. All these compounds exhibited intense perylene bisimide emission irrespective of the excitation wavelength at 397 nm (the feature absorption maximum of naphthalimide) or on excitation at the absorption maximum of perylene bisimide the fluorescence of naphthalimide dyes in compounds 1, 2 and 3 was drastically quenched. It could be a result of a highly efficient energy-transfer process from peripheral naphthalimide groups to the core perylene bisimide chromophores [10]. In conclusion, three novel naphthalimide functionalized perylene bisimide dyes were synthesized and characterized, using UV–vis and fluorescence spectroscopy. Introduction of naphthalimide groups to the perylene bisimide core via piperazidine units induced dramatic bathochromic shifts of their absorption and emission. The efficient energy transfer from the naphthalimide to the perylene bisimide core was observed. This fact, together with the high light absorption throughout the whole visible spectrum makes these compounds to be suitable candidates in organic solar cells. Acknowledgments This work was supported by National Natural Science Foundation of China and Shanghai Science Committee. References [1] [2] [3] [4] [5] [6]
P. Peumans, S. Uchida, S.R. Forrest, Nature 425 (6954) (2003) 158. M. Guo, P. Diao, S.M. Cai, Chin. Chem. Lett. 15 (9) (2004) 113. J.L. Wang, X.F. Duan, B. Jiang, L.B. Gan, J. Pei, C. He, Y.F. Li, J. Org. Chem. 71 (12) (2006) 4400. For example: Y. Li, H. Li, Y. Li, H. Liu, S. Wang, X. He, N. Wang, D. Zhu, Org. Lett. 7 (22) (2005) 4835. For example: J. Hua, F. Meng, F. Ding, F. Li, H. Tian, J. Mater. Chem. 14 (12) (2004) 1849. 1 H NMR and mass spectra data of compounds 1, 2 and 3. Compound 1: 1H NMR (500 MHz, CDCl3, d ppm): 10.09 (s, 1H), 8.71–8.53 (m, 8H), 8.47 (d, J = 8.3 Hz, 1H), 7.74 (t, J = 7.9 Hz, 1H), 7.40 (d, J = 7.9 Hz, 1H), 4.22 (m, 6H), 3.71–3.49 (m, 8H), 1.75 (m, 6H), 1.48 (m, 6H), 1.01 (m, 9H); MALDI-TOF: m/z (%): 838.36 [M+ + 1]. Compound 2: 1H NMR (500 MHz, CDCl3, d ppm): 9.81 (s, 1 H), 9.47 (d, 1H, J = 8.2 Hz), 8.89 (s, 1H), 8.68 (d, 1H, J = 8.2 Hz), 8.64 (s, 1H), 8.60 (m, 3H), 8.45 (d, 1H, J = 8.3 Hz), 7.73 (t, 1H, J = 7.8 Hz), 7.36 (d, 1H, J = 8.0 Hz), 4.22 (m, 6H), 3.76–3.40 (m, 8H), 1.75 (m, 6H), 1.48 (m, 6H), 1.00 (m, 9H); MALDI-TOF: m/z (%): 918.31 [M+ + 1]. Compound 3: 1H NMR (500 MHz, CDCl3, d ppm): 9.75 (s, 2 H), 8.63–8.45 (m, 8H), 8.37 (d, 2H, J = 8.4 Hz), 7.66 (m, 2H), 7.30 (m, 2H), 4.19 (t, 4H, J = 7.2 Hz), 4.12 (t, 4H, J = 7.2 Hz), 3.68–3.38 (m, 16H), 1.63 (m, 8H), 1.41 (m, 8H), 0.93 (m, 12H); MALDITOF: m/z (%): 1173.59.
286 [7] [8] [9] [10]
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286 L. Fan, Y. Xu, H. Tian, Tetrahedron Lett. 46 (26) (2005) 4443. K. Sugiyasu, N. Fujita, S. Shinkai, Angew. Chem., Int. Ed. 43 (10) (2004) 1229. Z. Chen, M.G. Debije, T. Debaerdemaeker, P. Osswald, F. Wu¨rthner, Chem. Phys. Chem. 5 (1) (2004) 137. C.C. You, C. Hippius, M. Gru¨ne, F. Wu¨rthner, Chem. Eur. J. 12 (28) (2006) 7510.
Synthesis and near-infrared characteristics of novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores Bo Gao, Yang Li, He Tian * Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science & Technology, Shanghai 200237, China Received 9 November 2006
Abstract Novel perylene bisimide dyes bay-functionalized with naphthalimide chromophores have been prepared conveniently by coupling of 1,8-naphthalimide and dibromoperylene bisimides. Their optical properties were investigated by UV–vis and fluorescence spectroscopy. The absorption spectra of these compounds showed wide spectral responses from 300 to 700 nm, which would be potentials for application as organic solar cells. # 2007 He Tian. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. Keywords: Perylene bisimide; Naphthalimide; Near-infrared
Organic solar cells are promising candidates for renewable sources of electrical energy, due to the advantages of low production cost, lightweight and capability to make flexible devices in comparison with the traditional siliconbased solar cells [1–3]. One important factor that governs the performance of a solar cell, is the absorption spectrum of the organic semiconductors or the dye molecules used for device fabrication. In an ideal situation, the solar cell’s absorption spectrum should completely cover the region of solar irradiation. Therefore, the development of novel dye molecules with appropriate absorptive properties for photon harvesting has become an important area. Perylene and its derivatives, especially perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI) have shown great promise in a variety of applications owing to their outstanding photochemical and thermal stability [4]. In particular, PBI dyes show unusual photocurrent amplification properties and have potential for application in solar cells [5]. We previously reported the perylene bisimide derivatives containing piperidine groups and the absorption maximum of such dyes have obvious bathochromic shift relative to the precursor due to the electron-donating ability of amines [7]. However, the width of the absorption band was not significantly expanded. Naphthalimide derivatives are well known as brilliant greenish-yellow dyes and exhibit absorption maxima around 400 nm. They have excellent photochemical and thermal stability.
* Corresponding author. E-mail address: [email protected] (H. Tian). 1001-8417/$ – see front matter # 2007 He Tian. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved. doi:10.1016/j.cclet.2007.01.014
284
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286
Fig. 1. The chemical structures of compounds 1, 2 and 3.
Herein, we incorporated the naphthalimide chromophores at 1- and/or 7 bay positions of perylene bisimide for the first time via piperazidine units and synthesized compounds 1, 2 and 3 (Fig. 1). The multichromophoric perylene bisimide derivatives show wide spectral responses from 300 to 700 nm. Perylene bisimide derivatives were synthesized by the reaction of 1,8-naphthalimide with dibromoperylene bisimides in N-methyl-2-pyrrolidone (NMP) under dry argon. The reactions are very sensitive to change of temperature. At room temperature the reactions were very slow, and monosubstituted perylene bisimide 2 was the major product; at high temperatures (above 130 8C) the 1-bromine is replaced by a hydrogen atom and compound 1 was formed as the major products. Selective formation of the desired product 3 was made possible by careful adjustment of temperatures. Compounds 1, 2 and 3 were characterized by 1H NMR and mass spectra [6] (Fig. 1). The optical properties of perylene bisimide derivatives 1, 2 and 3 in CH2Cl2 were investigated by UV/Vis and fluorescence spectroscopy. The absorption spectra of compounds 1, 2 and 3 are shown in Fig. 2. All of these compounds are highly soluble in various organic solvents, such as CH2Cl2, CHCl3, toluene and acetone. Introduction of naphthalimide groups at the 1- and/or 7-positions of perylene bisimide core induced dramatic bathochromic shifts relative to the lowest energy optical transition of the Br-substituted PBIs (lmax = 526 nm in chloroform) [7]. Compound 1 shows intense absorption bands with maxima at 578 (e = 2.50 104 mol L 1 cm 1) and 394 nm (e = 2.25 104 mol L 1 cm 1), which can be attributed to the perylene bisimide and naphthalimide moieties. Compared with the parent chromophores, the absence of additional absorption bands indicated insignificant groundstate interaction between these two chromophores. Compound 2 exhibited similar absorption profile, but the absorption maxima of the chromophores are shifted to 597 (e = 2.23 104 mol L 1 cm 1) and 397 nm (e = 2.31 104 mol L 1 cm 1), respectively. Progressive red-shifts of the absorption maxima occurred when two naphthalimide chromophores were incorporated to the perylene bisimide core. The absorption maxima of compound 3 are shifted to 646 (e = 2.05 104 mol L 1 cm 1) and 397 nm (e = 3.02 104 mol L 1 cm 1). Compared with Brsubstituted PBI [7], the feature absorption of perylene bisimide fragments broadened obviously in compounds 1, 2 and 3 (the half-band width of compounds 1, 2 and 3 in long wavelength are 116, 120 and 130 nm, respectively), which
Fig. 2. Absorption spectra of compounds 1, 2 and 3 in CH2Cl2 (c = 1.0 10
5
mol L 1).
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286
285
Fig. 3. Fluorescence spectra of compounds 1, 2 and 3 in CH2Cl2 (c = 1.0 10 5 mol L 1; (1) compound 1, lex = 578 nm; (2) compound 1, lex = 394 nm; (3) compound 2, lex = 597 nm; (4) compound 2, lex = 397 nm; (5) compound 3, lex = 646 nm; (6) compound 3, lex = 397 nm).
could be attributed to the following reasons. One could be the increase of the p-conjugation between the substituents and the perylene bisimide core [8]. Another could be the twisting of the perylene bisimide core by the substituents, so that the vibronic structure is lost [9]. Fig. 3 showed the fluorescence spectra of compounds 1, 2 and 3 in CH2Cl2. All these compounds exhibited intense perylene bisimide emission irrespective of the excitation wavelength at 397 nm (the feature absorption maximum of naphthalimide) or on excitation at the absorption maximum of perylene bisimide the fluorescence of naphthalimide dyes in compounds 1, 2 and 3 was drastically quenched. It could be a result of a highly efficient energy-transfer process from peripheral naphthalimide groups to the core perylene bisimide chromophores [10]. In conclusion, three novel naphthalimide functionalized perylene bisimide dyes were synthesized and characterized, using UV–vis and fluorescence spectroscopy. Introduction of naphthalimide groups to the perylene bisimide core via piperazidine units induced dramatic bathochromic shifts of their absorption and emission. The efficient energy transfer from the naphthalimide to the perylene bisimide core was observed. This fact, together with the high light absorption throughout the whole visible spectrum makes these compounds to be suitable candidates in organic solar cells. Acknowledgments This work was supported by National Natural Science Foundation of China and Shanghai Science Committee. References [1] [2] [3] [4] [5] [6]
P. Peumans, S. Uchida, S.R. Forrest, Nature 425 (6954) (2003) 158. M. Guo, P. Diao, S.M. Cai, Chin. Chem. Lett. 15 (9) (2004) 113. J.L. Wang, X.F. Duan, B. Jiang, L.B. Gan, J. Pei, C. He, Y.F. Li, J. Org. Chem. 71 (12) (2006) 4400. For example: Y. Li, H. Li, Y. Li, H. Liu, S. Wang, X. He, N. Wang, D. Zhu, Org. Lett. 7 (22) (2005) 4835. For example: J. Hua, F. Meng, F. Ding, F. Li, H. Tian, J. Mater. Chem. 14 (12) (2004) 1849. 1 H NMR and mass spectra data of compounds 1, 2 and 3. Compound 1: 1H NMR (500 MHz, CDCl3, d ppm): 10.09 (s, 1H), 8.71–8.53 (m, 8H), 8.47 (d, J = 8.3 Hz, 1H), 7.74 (t, J = 7.9 Hz, 1H), 7.40 (d, J = 7.9 Hz, 1H), 4.22 (m, 6H), 3.71–3.49 (m, 8H), 1.75 (m, 6H), 1.48 (m, 6H), 1.01 (m, 9H); MALDI-TOF: m/z (%): 838.36 [M+ + 1]. Compound 2: 1H NMR (500 MHz, CDCl3, d ppm): 9.81 (s, 1 H), 9.47 (d, 1H, J = 8.2 Hz), 8.89 (s, 1H), 8.68 (d, 1H, J = 8.2 Hz), 8.64 (s, 1H), 8.60 (m, 3H), 8.45 (d, 1H, J = 8.3 Hz), 7.73 (t, 1H, J = 7.8 Hz), 7.36 (d, 1H, J = 8.0 Hz), 4.22 (m, 6H), 3.76–3.40 (m, 8H), 1.75 (m, 6H), 1.48 (m, 6H), 1.00 (m, 9H); MALDI-TOF: m/z (%): 918.31 [M+ + 1]. Compound 3: 1H NMR (500 MHz, CDCl3, d ppm): 9.75 (s, 2 H), 8.63–8.45 (m, 8H), 8.37 (d, 2H, J = 8.4 Hz), 7.66 (m, 2H), 7.30 (m, 2H), 4.19 (t, 4H, J = 7.2 Hz), 4.12 (t, 4H, J = 7.2 Hz), 3.68–3.38 (m, 16H), 1.63 (m, 8H), 1.41 (m, 8H), 0.93 (m, 12H); MALDITOF: m/z (%): 1173.59.
286 [7] [8] [9] [10]
B. Gao et al. / Chinese Chemical Letters 18 (2007) 283–286 L. Fan, Y. Xu, H. Tian, Tetrahedron Lett. 46 (26) (2005) 4443. K. Sugiyasu, N. Fujita, S. Shinkai, Angew. Chem., Int. Ed. 43 (10) (2004) 1229. Z. Chen, M.G. Debije, T. Debaerdemaeker, P. Osswald, F. Wu¨rthner, Chem. Phys. Chem. 5 (1) (2004) 137. C.C. You, C. Hippius, M. Gru¨ne, F. Wu¨rthner, Chem. Eur. J. 12 (28) (2006) 7510.