Electronic and vibrational spectroscopic (FT-IR and FT-Raman) investigation using ab initio (HF) and DFT (B3LYP and B3PW91) and HOMO/LUMO/MEP analysis on the structure of l-serine methyl ester hydrogen chloride

Abstract

The vibrational spectroscopy (Fourier Transform Raman and Infrared spectra) of l-serine methyl ester hydrogen chloride (LHCL) have been recorded and the observed vibrational frequencies are assigned and tabulated. The Gaussian hybrid computational calculations were determined by HF and DFT (B3LYP and B3PW91) methods with 6–31++G(d,p) and 6–311++G(d,p) as basis sets. The mulliken and natural charge in the functional group has the maximum magnitude of 0.305 and 0.498 among the hydrogen atoms present in the compound and here, the entire hydrogen atoms exhibit a net positive charge. The change of structure of amino acid due to the addition of subsequent substitutions of methyl, ethyl, carboxylic and hydroxyl chain is investigated. It plays a vital role in the production of different pharmaceutical and cosmetics industries.13C NMR and 1H NMR were calculated by using the gauge independent atomic orbital (GIAO) method with the B3LYP methods and the 6-311 + G(d,p) basis set and nuclear magnetic resonance chemical shifts related to TMS were compared. A study on the optoelectronics properties: absorption wavelengths, excitation energy, oscillator strength, dipole moment and FMO were executed by the HF and DFT methods. UV–Visible spectrum of the present compound is recorded in the region is 200–400 nm and the electronic properties HOMO and LUMO energies are deliberated by TD-DFT method. The polarizability, anisotropy, dipole moment and first order hyperpolarizability of the molecule have been discussed.