Experimental and computational insights into the synthesis and characterization of a novel Schiff base ligand 2, 2′-[(1z, 14e)-2, 5, 8,11,14-pentaazapentadeca-1, 14-diene-diyl] diphenol

Abstract

A novel Schiff base of N1,N5-Bis(salicylidene) tetraethylene pentamine (BSTEPA) was synthesized by using reflux method. The prepared molecule has been characterized using 1H NMR and IR spectral methods. The complete vibrational characterization of the molecule was performed using experimental (FTIR and FT-Raman) spectra and calculations at Density Functional Theory (DFT) level. In order to perform a detailed vibrational spectroscopic analysis of BSTEPA, Fourier Transform Infrared (FTIR) and Fourier Transform Raman (FT-Raman) spectra were recorded in condensed phase and used as such. Density Functional Theory calculations in the B3LYP/6-31G** level have been carried out on the title molecule in order to determine the optimized geometry and vibrational wavenumbers. The ultraviolet visible (UV–Vis) spectra of BSTEPA were recorded in the range of 300–500 nm for various solvents. The natural bond orbital and frontier molecular orbital analyses were also performed at same DFT level of calculations.