Molecular Geometry, NBO analysis, Frontier molecular orbitals, First order Hyper polarizability, and Vibrational Studies on Potential NLO

1N-methyl-1S-methyl-2-nitroethylene (NMSM) is an important intermediate in the synthesis of anti-ulcer drug Ranitidine. NMSM is a push pull alkene equivalent to glycine possessing both electron-donating and withdrawing nitro group at both ends of olefinic bond. The solid phase FT-IR and FT-Raman spectra of NMSM have been recorded in the region 4000-400cm and 3500-100cm, respectively. The molecular geometry, harmonic vibrational frequencies and bonding features of NMSM in the ground state have been calculated by density functional theory method using 6-311G(d,p) basis set. The molecular stability arising from hyperconjugative interaction and charge delocalization has been analyzed using natural bond orbital (NBO) analysis. The calculated first order hyperpolarizability of NMSM is found to be 4.52 × 10 e.s.u. which is 23 times that of urea standard.