A Probe to Surface Reactivity, Crystal Structure, and DFT Investigations for Newly Synthesized 4,5-bis(4-Nitrophenyl)-8a-phenyl-decahydro-[1,3]diazino[4,5-d]pyrimidine-2,7-dione: A Combined Theoretical and Experimental Study

Abstract

The multicomponent reaction of 4-nitrobenzaldehyde with acetophenone and urea in the presence of HCl was investigated, and, as a result, 4,5-bis(4-nitrophenyl)-8a-phenyl-decahydro-[1,3]diazino[4,5-d]pyrimidine-2,7-dione was synthesized. The structure of the synthesized compound was confirmed by the X-ray method. We performed Hirshfeld surfaces (HS) analysis and two-dimensional (2D) fingerprint plots for the studied compound to obtain surface reactivity and intermolecular interactions. The H∙∙∙H interactions were found to be higher, up to 32.2%, while the percentage C∙∙∙O contact was found to be the lowest among the reported interactions for single crystal packing. The energy framework analysis shows the strength of interaction energy within fragments of a single crystal at 3.08 A distances. The DFT study shows structural reactivity and a reduced HOMO-LUMO gap up to 4.0 eV. The NPA study reveals the reactivity and excellent charge transfer within the structure. The TD-DFT study reveals the absorbance in the UV region and excited state parameters during crucial transitions (transitions with maximum oscillator strength). The investigated compound shows excellent optical and nonlinear optical (NLO) properties, as indicated by its polarizability (αo) and hyperpolarizability (βo) values.