Spectroscopic, DFT and Z-scan approach to study linear and nonlinear optical properties of Disperse Red 277

Abstract

Nonlinear optical properties of 4-(diethylamino)-7-imino-7H-benzo[4,5]imidazo[1,2-a]chromeno[3,2-c]pyridine-6-carbonitrile (C.I. Disperse Red 277), a red fluorescent dye estimated spectroscopically are found in good agreement with the values estimated with density functional theory based on ab initio method using the global hybrid (GH) and range separated hybrid (RSH) functionals in combination with the basis sets (6–311++G (d,p)), (cc-pVDZ) and (cc-pVTZ). Z-Scan measurement suggests that dye possess large third order nonlinear optical (NLO) properties. Estimated polarizability (αCT), first order hyperpolarizability (β0) and second order hyperpolarizability (γ) from the, GH functionals - BMK, M062X and the RSH functionals – M11, CAM-B3LYP, HISSbPBE are having very nearly similar values and are in close agreement with spectroscopically obtained values. Solvent environment plays influential role in NLO properties of this dye as solvent polarity increases the NLO characteristics also increase from non-polar to polar solvents. The dye has shown highest NLO response. Δα, β0, γ and α0 values increase with decreasing HOMO-LUMO band gap.