Pyrene Based NLOphoric D‐π‐A‐π‐D Coumarin‐Chalcone and Their Red Emitting OBO Difluoride Complex: Synthesis, Solvatochromism, Z‐scan, and Detailed TD‐DFT Studies

Abstract

AbstractNLOphoric D‐π‐A‐π‐D coumarin chalcone 5 and their BF2 complex 6 were designed, synthesized and characterized through Mass,13C‐NMR, and 1H‐NMR analysis. Their Photophysical properties are extensively studied in solvents of different polarity. On BF2 complexation of coumarin chalcone shows highly red shift in absorption and emission spectra compared to uncomplexed coumarin chalcone. Positive solvatochromism observed which is well supported by linear and multilinear regression analysis. For BF2 complexed coumarin‐chalcone 6 the solvent dipolarity (CSdP) is the main factor responsible for slightly red shift in absorption spectra, and also for the highly red‐shift in emission spectra. Frontier molecular orbital, molecular electrostatic potential and Generalized Mulliken‐Hush analysis revealed intramolecular charge transfer in these compounds. Nonlinear optical (NLO) properties for compounds 5 and 6 were studied by solvatochromic and computational method. The linear polarizability (α), first‐order hyperpolarizability (β) and second‐order hyperpolarizability (γ) of compounds were studied by the time dependent density functional theory using three different functionals namely B3LYP, BHHLYP and CAM−B3LYP with the 6–31 G (d) basis set. BF2 complexed compound 6, show higher values for αe + αv as well as βe+βv compared to compound 5. Third order nonlinear optical susceptibility (χ(3)) of these compounds obtained by Z‐scan analysis. Third‐order (χ(3)) non‐linear optical properties of BF2 complexed coumarin‐chalcone 6 were observed to be several times higher than those of the uncomplexed coumarin‐chalcone 5 these justify the design approach.