Photophysical and electrochemical properties and temperature dependent geometrical isomerism in alkyl quinacridonediimines

Abstract

Quinacridone diimines 1-10 were synthesized by the condensation of anilines with alkyl substituted quinacridones (QA). Photophysical and electrochemical properties of the compounds were investigated. Unconventional behavior of absorption spectra suggested a decrease in p _ conjugation within the QA skeleton as well as lack of extended p _ conjugation between the QA skeleton and the N-phenyl rings. A computational study of compounds 1-10, a variable temperature 1 H NMR study of compounds 2, 7 and 10 (for instance), and single crystal X-ray analysis of 2, 3, 6, 7, 8 and 10 indicated that the anomalous behavior is due to the buckled, non-planar structure of the quinacridones. Moreover the molecules existed in two interconvertible geometric isomeric forms at different temperatures. Molecular orbital calculations were performed at B3LYP/6-31+G(d), B3PW91/6-31G(d) and PBEPBE/6-31G(d) levels of theory at B3PW91/6-31G(d) optimized structures for both isomers of all compounds (1-10); the results obtained are in close agreement with the experimentally determined values.

Isolation, spectroscopic and density functional theory studies of 7-(4-methoxyphenyl)-9H-furo[2,3-f]chromen-9-one: A new flavonoid from the bark of Millettia ovalifolia

“…The B3LYP method consists of three parameter hybrid functional of Becke [14] in conjunction with the correlation function of Lee et al [15]. The B3LYP method provides a nice balance between cost and accuracy, and it is known to perform very well for the prediction of geometries of a number of synthetic [16][17][18][19] and natural products [20,21]. In order to find any low energy existing structure, conformation analysis of the compound 1 was performed in methanol solvent.…”

Spectroscopic and density functional theory studies of 7-hydroxy-3′-methoxyisoflavone: A new isoflavone from the seeds of Indigofera heterantha (Wall)

“…The B3LYP method consists of three parameter hybrid functional of Becke [10] in conjunction with the correlation functional of Lee, Yang, and Parr [11]. B3LYP is a cost effective method for accurate prediction of geometries of a number of synthetic [12][13][14] and natural products [15,16]. The lowest energy structure of the isoflavone 1 was obtained through conformational analysis around C4-C3-C1'-C6' dihedral angle at B3LYP/6-311G (d,p)(see Figure 1 for labelling).…”

“…The theoretical NMR is also calculated using Cramer re-parameterized WP04 functions at 6-311G(d,p) basis set. The NMR was calculated using GIAO formalism using, and the solvent effect was introduced through polarizable continuum model (PCM).NMR A comparison of the theoretical 1 H and 13 C NMR values with the experimental values is given in The theoretical 13 …”

“…The 1 H and 13 C NMR spectra were recorded in CDCl 3 at 500 and 125 MHz on Bruker AM-500) nuclear magnetic resonance spectrometers using internal reference (TMS). The heteronuclear 2D 1 H- 13 column chromatography was carried out via (Si 60, 230-400 mesh, E. Merck) silica gel as adsorbent using Eyela Flash Chromatograph model known as EF-10. In addition to it, (20×20, 0.5 mm thick; E. Merck) pre-coated silica gel GF 254 preparative glass plates were applied for thick layer chromatography.…”

Efficient Synthesis by Mono‐Carboxy Methylation of 4,4′‐Biphenol, X‐ray Diffraction, Spectroscopic Characterization and Computational Study of the Crystal Packing of Ethyl 2‐((4′‐hydroxy‐[1,1′‐biphenyl]‐4‐yl)oxy)acetate

“…The FMO insight is an essential parameter for the assessment of chemical strength of molecule. [29] The quantum orbitals as highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) can contribute a significant role in UV-Vis spectrum and mechanistic study of studied molecules. In generic way, LUMO is considered as electron acceptor orbital while, HOMO is considered as electron donator orbital.…”