wizyta

od 2020-09-20

Title: Synthesis, characterization and photophysical properties of novel 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles

Source: Journal of Molecular Structure

Year : 2016

Abstract:

Three 5,7-disubstituted-1,4-diazepine-2,3-dicarbonitriles with bulky 2-(3,5-dibromophenyl)ethenyl, 2-(4-tert-butylphenyl)ethenyl and 2-(3,5-dibenzyloxyphenyl)ethenyl substituents were synthesized and characterized using UV-Vis, MS ES, elemental analysis and NMR spectroscopy. NMR data indicated that diazepine rings of all obtained compounds adopted 6H-tautomeric form. In addition, trans-isomerism within styryl substituents was observed. Experimental data for diazepine derivative containing 2-(4-tertbutylphenyl)ethenyl substituents were verified by X-ray crystallography. The obtained compounds were subjected to photophysical studies. In the UV-Vis absorption spectra two characteristic bands were found. In the solvatochromic study, the first band maxima were located in the range of 384-418 nm, whereas second band maxima in the range of 313-345 nm. Fluorescence intensity of novel diazepine derivatives was rather low in all solvents used with the values of fluorescence quantum yield Phi(F) (=) 10(-4) for 2-(3,5-dibromophenyl)ethenyl, and 10(-5) for 2-(4-tert-butylphenyl)ethenyl and 3,5-(dibenzyloxyphenyl)ethenyl 1,4-diazepine-2,3-dicarbonitriles. (C) 2016 Elsevier B.V. All rights reserved.

DOI: 10.1016/j.molstruc.2016.01.032   (Pobrane:  aktualizowanie)