DFT and Spectroscopic Investigation of a Triphenyltin–Salicylate–Triphenylphosphine Oxide Complex

Abstract

Organometallic compounds, particularly organotin compounds, are of crucial importance in catalysis and molecular stabilization due to the polarity and reactivity of Sn–C bonds. In order to gain a detailed understanding of the structural and electronic behavior of organometallic compounds, it is essential to adopt an integrated approach that includes theoretical simulations. This work comprises an in-depth theoretical analysis using Density Functional Theory (DFT), aimed at elucidating the molecular structure, electronic properties, and spectroscopic attributes of the crystalline complex (2-hydroxybenzoato-κO) triphenyl (triphenylphosphine oxide-κO) tin (IV), with the formula C₆H₄ (OH)CO₂SnPh₃OPPh₃.  Furthermore, the study of Mulliken and NBO charge distributions and global descriptors indicate that the complex exhibits moderate electronic stability accompanied by a pronounced electrophilic character. Frontier molecular orbital (HOMO–LUMO) analysis highlights an intramolecular charge transfer (ICT) from the donor ligand to the acceptor center across the entire molecule. In addition, theoretical spectral analysis, including infrared (IR) spectra, further validates the chosen computational approach. These results demonstrate the importance of ligands in tuning the electronic and spectroscopic properties of the tin(IV) complex, emphasizing the relevance of such molecules for potential applications in materials chemistry and molecular sciences.