Theoretical Studies on Electronic Spectra and Second‐order Nonlinear Optical Properties of Glucosyl Substituted Barbituric Acid Derivatives

Abstract

AbstractAM1 semi‐empirical method was used to optimize the barbituric acid derivatives substituted with glucosyl B1–5(series B), and the thiobarbituric acid derivatives substituted with glucosyl T1–5 (seriesT). Based on the optimized structures, INDO/CI method was adopted to calculate the electronic spectra. Meanwhile, the second‐order nonlinear optical (NLO) coefficients βμ were calculated with the sum‐over‐state (SOS) formula. The results show that when the number of glucosyl units was increased, |βμ| values of the barbituric and thiobarbituric acid derivatives were both enhanced, especially for thiobarbituric acid derivatives. It indicates that non‐conjugated substituted group could also improve NLO properties of materials when the number of repeated units was increased. Additionally, the absorption bands appearing in UV area are consistent with the proper change of the number of glucosyl units, and consequently it can be concluded that the high transparencies of all systems were scarcely varied.