Crystal structure, Hirshfeld surface, spectroscopic analyses, electronic properties, NLO profile and thermochemical study of an antispasmodic agent trimebutine

Absolute molecular geometry of trimebutine was determined with single crystal X-Ray diffraction (SCXRD). The C-H center dot center dot center dot O and C-H center dot center dot center dot pi interactions within crystal packing were supported by Hirshfeld surface analysis. Spectral properties of trimebutine were investigated by using analysis techniques such as FT-IR, micro-Raman, NMR chemical shift and UV-Vis. spectroscopies. In order to investigate vibrational profile of the important functional groups within the compound, the detailed assignments of vibrational wavenumbers were performed by using potential energy distribution. Theoretical investigations on structural, spectroscopic, electronic, non-linear optical and thermochemical features were carried out with the DET/B3LYP method at the 6-311++G(d,p) basis set. The C-13 and H-1 NMR chemical shifts of each atom within the compound were studied both experimentally and theoretically. The UV-Vis. spectroscopic analysis of trimebutine was used to evaluate intra-molecular electronic transitions. The HOMOs and LUMOs analyses were done to determine the nature and origin of the pi ->pi* and n ->pi* electronic transitions. Additionally, the global reactivity descriptors were defined depending upon energy values of HOMO and LUMO. The pi ->pi* and n ->pi* hyperconjugative interactions between donor and acceptor groups were investigated by NBO analysis. According to the computed alpha(total), Delta alpha and beta(0) values in the static state of trimebutine single crystal, it exhibits an excellent non-linear optical material property. Thermochemical features were calculated and studied in the gas phase of the compound. (C) 2019 Elsevier B.V. All rights reserved.