Design and synthesis of amino acid appended azo dye hybrid: Characterization, solvatochromic and quantum-chemical calculations using experimental and theoretical approach

Abstract

Amino acid appended azobenzene hybrid was synthesized and characterized using Spectroscopic techniques like 1H NMR, 13C NMR, FT-IR and Mass spectrometry analysis and its optical properties were investigated using UV–vis absorption and fluorescence spectroscopy in solvents of different polarity. Based on solvent refractive index and relative permittivity, by using the theory of solvatochromism, the excited-state (μe) and ground-state (μg) dipole moments was determined for (E)-4-((4-(heptyloxy)phenyl)diazenyl)benzyl((benzyloxy)carbonyl)glycinate (Gly-Azo-O7) based on the variation of Stokes shift as an effect of various solvent's. A bathochromic shift observed in absorption and emission spectra with increasing solvent polarity, which implied that the transition involved is π → π*. The ground state and excited state dipole moments were also calculated and compared using experimental and DFT calculations.