Molecular structure, vibrational spectroscopic (FT-IR, FT-Raman), NBO, HOMO and LUMO analysis of morpholinium oxalate by density functional method

A new organic nonlinear optical morpholinium oxalate (MO) single crystal was grown from low temperature solution growth method. Single crystal XRD was utilized to calculate the lattice constants, the molecular arrangements and the formation of hydrogen bonds in the MO compound. Vibrational analysis was utilized to identify the assorted functional groups existing in the compound. The optimized structure, electronic properties and frontier energy gap was scrutinized by DFT (density functional theory). The DFT supports to construe the charge transfer from oxalic acid to morpholine in the compound. NBO (natural bond orbital) computations were utilized to evaluate the stabilities occurs from charge delocalization and intermolecular interactions in the MO crystal. The H-1 and C-13 NMR spectrum confirms the protonation of the compound. The first-order hyperpolarizability was estimated to be 8.31 x 10(-31) esu. (C) 2018 Published by Elsevier B.V.