Journal of Molecular Structure Volume 1146, 15 October 2017, Pages 554–561
Anastasiia M. Afanasenko, Dina V. Boyarskaya, Irina A. Boyarskaya, Tatiana G. Chulkova, Yakov M. Grigoriev, Ilya E. Kolesnikov, Margarita S. Avdontceva, Taras L. Panikorovskii, Andrej I. Panin, Anatoly N. Vereshchagin, Michail N. Elinson
Structures and photophysical properties of 3,4-diaryl-1H-pyrrol-2,5- diimines and 2,3-diarylmaleimides
Journal of Molecular Structure Volume 1146, 15 October 2017, Pages 554–561
DOI: 10.1016/j.molstruc.2017.06.048
Structural features of 3,4-diaryl-1H-pyrrol-2,5-diimines and their derivatives have been studied by molecular spectroscopy techniques, single-crystal X-ray diffraction, and DFT calculations. According to the theoretical calculations, the diimino tautomeric form of 3,4-diaryl-1H-pyrrol-2,5-diimines is more stable in solution than the imino-enamino form. We also found that the structurally related 2,3-diarylmaleimides exist in the solid state in the dimeric diketo form. 3,4-Diaryl-1H-pyrrol-2,5-diimines and 2,3-diarylmaleimides exhibit fluorescence in the blue region of the visible spectrum. The fluorescence spectra have large Stokes shifts. Aryl substituents at the 3,4-positions of 1H-pyrrol-2,5-diimine do not significantly affect fluorescence properties. The insertion of donor substituents into 2,3-diarylmaleimides leads to bathochromic shift of emission bands with hyperchromic effect.
