Comprehensive structural characterization and Quantum mechanical exploration of o-phenylenediamine Dihydrogenphosphate: An integrated theoretical and experimental approach

Abstract

Inorganic-organic hybrid materials merge the best of both inorganic and organic properties, enabling enhanced performance in diverse applications. The present study elucidates the crystallographic attributes of O-Phenylenediamine Dihydrogenphosphate (OPDP; C6H11N2O4P), crystallized in an ethanol medium. Characterized by a triclinic lattice, the asymmetric unit contains a single molecule (Z'=0), while the unit cell is comprised of eight molecules (Z = 2). The overall architecture is connected by intermolecular NH···O hydrogen bonds, which give rise to a bi-dimensional supramolecular framework. To substantiate the experimental findings and to probe the molecule's particular attributes, Fourier Transform Infrared Spectroscopy was deployed, owing to its sensitivity to inter/intra-molecular interactions within crystal systems. Density Functional Theory (DFT) calculations were performed using B3LYB functional, yielding molecular structure optimization, vibrational frequencies, and molecular properties such as Mulliken atomic charge distribution and frontier molecular orbital. Functional groups were discerned using FTIR spectroscopy and compared with theoretical predictions. The molecule features fourteen HH and three OH bonds. Natural Bond Analysis (NBO) was conducted to evaluate stabilization energy in donor–acceptor transitions. Surface morphology was examined using Scanning Electron Microscopy (SEM) in conjunction with Energy-Dispersive X-ray Spectroscopy (EDX). This comprehensive study advances our understanding of the unique structural and molecular properties of OPDP, demonstrating its potential for multifaceted applications.