Experimental and DFT/TD-DFT approach on photo-physical and NLO properties of 2, 6-bis (4-Chlorobenzylidene) cyclohexanone

Abstract The crystalline nature and lattice parameters of synthesized compound 2, 6-bis (4-Chlorobenzylidene) cyclohexanone (B4CBC) were confirmed by powder X-ray diffraction technique. The splitting of the carbonyl mode is attributed to the intramolecular association on the basis of C O ….H type hydrogen bonding in the molecule. The doublet of the C O mode band originates from Fermi resonance. The solvatochromic behaviour of B4CBC in acetone solvent was investigated by UV–Vis, fluorescence spectroscopy and supported by TD-DFT calculations. Fluorescence lifetime measurement of the title compound exhibits a lifetime of the order of 2–3 ns and blue emission observed from CIE chromatic diagram. Decay curve also shows that excited state life time of BBC is longer, indicating that the chlorine substituent atom has a significant impact on the excited state relaxation process. Our result shows that NLO response and photo-physical parameters of cyclohexanone derivatives are tunable via peripheral substituent chlorine atom.