Charge Transfer Parameters, Correlative Perturbation Potential with Non‐Linear Optical Properties of Bi‐Heterocyclic Dyes Having TCF Acceptor‐ DFT Approach

Abstract

AbstractWe have designed ten molecules having “donor‐π‐acceptor system”. Coumarin and carbazole connected to tricyanofuran acceptor unit are selected to study their “ground state” structural and NLO properties. Six functionals with five solvents are used to obtain vertical excitation and hyperpolarizabilities. “Amplitude of sine‐shaped potential” decreases with increase in conjugation chain and solvent polarity. Frontier molecular orbital (FMO), molecular electrostatic potential (MEPS), bond length alteration (BLA), quinoid character (δr) showed intramolecular charge transfer (ICT). HOMO‐LUMO depends on donor strength and solvent environment. N‐Alkyl substituted donors showed red shifted vertical excitations, higher dipole moments and higher hyperpolarizabilities. Perturbation potential have correlation with BLA, quinoid character, hyperpolarizabilities and hyperhardness. Using DFT, NLO parameters such as‐(β0) and (γ) are calculated with six different functionals‐ including global hybrid (GH) and range separated hybrid (RSH) (B3LYP, BHandHLYP, CAM‐B3LYP, ωB97, ωB97X, and ωB97X‐D). Higher (β0) 213×10−30(esu) and (γ) 791×10−30(esu) obtained using B3LYP functional for NCou 1. Standard deviation and mean absolute error calculated to check usefulness of functional. DFT descriptors, chemical potential (μ), chemical hardness (η), electrophilicity index (ω) and hyperhardness are produced. DFT descriptors are correlated with calculated NLO parameters.