2-(1,1-dioxidobenzobthiophen-3(2H)-ylidene)malononitrile (BTD) Based Styryl Chromophores- Solvatochomic and Computational Investigation of Linear and NLO properties

摘要

abstract_textpLinear and nonlinear optical properties of the twelve styryl dyes are investigated using density functional theory (DFT). Range-separated hybrid CAM-B3LYP and global hybrid BHandHLYP estimate high second order hyperpolarizability. Mean polarizability (alpha(0)), polarizability anisotropy (Delta alpha), static first-order hyperpolarizability (beta(0)) and second hyperpolarizability (gamma) were found to be overestimated in CAM-B3LYP than in BHandHLYP. As bond length alternation (BLA) increases first order hyperpolarizability increases. Multilinear regression analysis (MLR) shows the solvent basicity, polarizability and dipolarizabilty are responsible for absorption solvatochromism. The ratio of the dipole moments increases as donor strength and conjugation increases which support charge transfer. The figure of merit (FOM) and intrinsic hyperpolarizability found more in chromophores with dialkylamine donors. As the stability indicated by electrophilicity indices decreases the hyperpolarizability increases. Interrelationships between alpha(0), beta(0) and gamma were evaluated and it shows good linear fit. Absorption is red shifted and hyperpolarizability increases with the amplitude of the sine-shaped potential along the conjugation chain. A high molecular electrostatic potential was observed in dyes containing 2-piperidinothiophene donor./p/abstract_text