Rigidified malononitrile- and ketone-merocyanines in rigid environments
Keywords:pigments, dyes, crystal structure, powder diffraction, IR spectroscopy, UV-vis spectroscopy
Two merocyanine dyes containing a malononitrile or a ketone functional group as electron-acceptors, and a piperidine group as electron-donor were synthetized and crystallized as pigments. The electron-donor and -acceptor moieties are linked via an octahydroanthracene skeleton, forming an electronic push-pull molecular system. The crystal structure of the malononitrile compound was solved ab initio from X-ray powder diffraction data, complementing the reported structure of the ketone pigment. Both compounds show similar molecular structures in the solid state, yet with completely different crystal packing schemes. The crystal structures were analysed with inspecting the Hirshfeld surfaces. IR spectroscopy was applied to complement the crystallographic study. The absorption characteristics of both pigments emerge from the push-pull chemical structure, which was visualized by plotting the electrostatic potentials, calculated using molecular geometries as observed in the solid state. The solid state UV-vis spectra showed peak broadening and bathochromic spectral shift as compared to the spectra recorded in solution, depending on the polarity of the solvent molecules: The largest shifts of the spectra of solid state pigments were observed with respect to the spectra recorded in toluene solution, whether the smallest to those in ethanol.
A. Kazlauciunas, The role of colorants in the generation, storage, and output of digital still images, Color. Technol., 130, 8–12 (2014).
R. L. Gieseking, S. Mukhopadhyay, C. Risko, S. R. Marder, and J.-L. Brédas, 25th Anniversary Article: Design of Polymethine Dyes for All-Optical Switching Applications: Guidance from Theoretical and Computational Studies, Adv. Mater., 26, 68–84 (2014).
M. Wainwright, Dyes in the development of drugs and pharmaceuticals, Dyes Pigments, 76, 582–589 (2008).
S. H. Kim, Functional Dyes, Elsevier (2006).
F. Würthner, T. E Kaiser, C. R. Saha-Möller, Aggregates: From Serendipitous Discovery to Supramolecular Engineering of Functional Dye Materials, Angew. Chem. Int. Ed., 50, 3376–3410 (2011).
A. S. Abd-El-Aziz, E. A. Strohm, R. M. Okasha, Design and spectroscopic characterization of novel series of near infrared indocyanine dyes, J. Mol. Struct., 1091, 228–235 (2015).
A. V. Kulinich, A. A. Ishchenko, Merocyanine dyes: synthesis, structure, properties and applications, Russ. Chem. Rev., 78, 141–164 (2009).
U. Lawrentz, W. Grahn, K. Lukaszuk, C. Klein, R. Wortmann, A. Feldner, and D. Scherer, Donor-Acceptor Oligoenes with a Locked all-trans Conformation: Synthesis and Linear and Nonlinear Optical Properties, Chem. - Eur. J., 8, 1573–1590 (2002).
K. C. Kreβ, T. Fischer, J. Stumpe, W. Frey, M. Raith, O. Beiraghi, S. H. Eichhorn, S. Tussetschläger, S. Laschat, Influence of Chromophore Length and Acceptor Groups on the Optical Properties of Rigidified Merocyanine Dyes, Chem. Plus Chem., 79, 223-232 (2014).
M. A. Spackman, D. Jayatilaka, Hirshfeld surface analysis, Cryst. Eng. Commun., 11, 19-32 (2009).
M. A. Spackman, J. J. McKinnon, D. Jayatilaka, Electrostatic potentials mapped on Hirshfeld surfaces provide direct insight into intermolecular interactions in crystals, Cryst. Eng. Commun., 10, 377-388 (2007).
Bruker AXS, Topas, version 4.2. 2007.
A. A. Coelho, Indexing of powder diffraction patterns by iterative use of singular value decomposition, J. Appl. Cryst., 36, 86-95 (2003).
G. S. Pawley, Unit-cell refinement from powder diffraction scans, J. Appl. Cryst., 14, 357-361 (1981).
A. A. Coelho, Whole-profile structure solution from powder diffraction data using simulated annealing, J. Appl. Cryst., 33, 899-908 (2000).
H. M. Rietveld, A profile refinement method for nuclear and magnetic structures, J. Appl. Cryst., 2, 65-71 (1969).
CrystalExplorer (Version 3.1), S.K. Wolff, D.J. Grimwood, J.J. McKinnon, M.J. Turner, D. Jayatilaka, M.A. Spackman, University of Western Australia, (2012).
H. Mustroph, K. Reiner, B. Senns, J. Mistol, S. Ernst, D. Keil, L. Hennig, The Effects of Substituents and Solvents on the Ground-State π-Electronic Structure and Electronic Absorption Spectra of a Series of Model Merocyanine Dyes and Their Theoretical Interpretation, Chem. - Eur. J., 18, 8140–8149 (2012).
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