Theoretical Studies on Electronic Structures and Spectroscopy of Fluorescent Arylamino Fumaronitrile

Abstract

A new series of fluorescent arylamino fumarinitrile derivatives was designed and optimized using density function theory at the B3LYP/6-31G* level. Based on the optimized geometries, the electronic, fluorescent and 13C NMR spectra are calculated with INDO/CIS, CIS-ZINDO TD, and B3LYP/6-31G* methods, respectively. Starting with the first of the series, the LUMO-HOMO energy gaps of the derivatives become wider and the fluorescent wavelengths and the main peaks in the electronic spectra are blue-shifted owing to the large steric effect of naphthyl rings. On the contrary, the energy gaps of the derivatives turn narrow, and the fluorescent wavelengths and the main peaks in the electronic spectra are red-shifted since hydroxyl groups improve the symmetry and extend the conjugation system. The chemical shifts of sp2-C on the phenyl rings are moved upfield, while chemical shifts of carbon atoms on the cyano groups and those connected with the cyano groups are changed downfield in the presence of hydroxyl groups.