X-ray and DFT calculations of novel spiroisoxazolines derivatives

The present study describes a DFT and X-ray diffraction of spiroisoxazolines derivatives. The title compounds 3b-c have been characterized using single-crystal X-ray diffraction; Both compounds crystallize in orthorhombic system with space group P2(1)2(1)2(1). The organic molecule is built up from fused five-and ten membered rings, with an additional epoxy ring system and a 3-(4-chlorophenyl)-4,5-dihydroisoxazole or 3-(4-methoxyphenyl)-4,5-dihydroisoxazole groups as a substituent. In the crystal, intermolecular O-H & BULL;& BULL;& BULL;O and C-H & BULL;& BULL;& BULL;O hydrogen bonds and C-H & BULL;& BULL;& BULL;pi interactions lead to the formation of a three-dimensional framework. Hirshfeld surface analysis and 2D fingerprint revealed the nature of intermolecular contacts. In all compounds, H & BULL;& BULL;& BULL;H interactions are major interactions followed by H & BULL;& BULL;& BULL;O/O & BULL;& BULL;& BULL;H and H & BULL;& BULL;& BULL;C/C & BULL;& BULL;& BULL;H. Energy frameworks were constructed through different intermolecular interaction energies to investigate the stability of the compounds. Additionally, DFT study at B3LYP level of theory and 6-311G(d, p) basis set to investigate the optimized geometry in the gas phase, molecular electrostatic potential (MEP) map analysis and Mulliken charges were produced by using the optimized structures. The natural bond orbital (NBO) analysis is conducted to explore the interactions among different orbital and lone pairs taking place within the compounds. (c) 2022 Elsevier B.V. All rights reserved.