Synthesis, structural and spectroscopic evaluations and nonlinear optical properties of 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioic O-acid

Abstract

In this study, we report a combined experimental and theoretical study on 3,5-bis(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole-1-carbothioic O-acid (C18H18N2O3S) molecule. The compound crystallizes in the trigonal space group R-3 with a = b = 27.7151(12) Å, c = 12.4866(6) Å, ? = ? = 90.0°, ? = 120.0° and Z = 18. The crystal packing is stabilized by OH?O and OH?S intermolecular hydrogen bonds. These hydrogen bond interactions are also proved by NBO analysis. A detailed spectroscopic investigation is performed by the application of FT-IR and FT-NMR in addition to the theoretical approaches. Small energy gap between the frontier molecular orbitals is responsible for the nonlinear optical activity of the title molecule. © 2014 Elsevier B.V. All rights reserved.