Tautomerism, spectroscopic and computational analysis of Schiff base and its diphenyltin (IV) complex

Present work deals with the synthesis of Schiff base and its corresponding diorganotin (IV) complex with general formula Ph2SnL [Where Ph = Phenyl, L = 6,6'-((1Z,1'E)-((4-nitro-1,3-phenylene) bis(azanylylidene)) bis(methanylylidene)) bis(2-methoxyphenol)]. Synthesized Schiff base and organotin(IV) complex have been structurally characterized by various spectroscopic techniques namely FTIR, H-1 and C-13 NMR and UV-Visible. Computational investigation has been done at B3LYP/6-311 + G(d,p) and MPW1PW91/6-311 + G(d,p)/LANL2DZ level to obtain the molecular geometry, thermochemical values and vibrational frequencies for both Schiff base & its complex in the ground state. Potential energy distribution (PED) was also assigned for vibrational frequencies of Schiff base and its complex using VEDA software. Tautomerism of Schiff base was also investigated using DFT method. HOMO-LUMO energy distribution and electron density based parameters were calculated to understand the chemical behaviour of the Schiff base and its complex. A good correlation is obtained between experimental and theoretical results. Nucleophilic and electrophilic sites are investigated through the MEP computation. Intramolecular interactions of Schiff base and its complex have been analyzed using Natural bond order (NBO) analysis. Non-linear optical parameters (NLO) were investigated theoretically to check frequency shifting response of the Schiff base and its complex. Both Schiff base and its diphenyltin (IV) complex show good optical properties which can be further explored for the application in OLED devices. (C) 2019 Elsevier B.V. All rights reserved.