First-principles study of structure and bonding in Ni-group transition metal carbonyls with terminal tin chalcogenides [M(CO)3SnX] (M = Ni, Pd, Pt; X = O, S, Se, and Te) complexes

Abstract

This analysis employs atomistic molecular modelling based on density functional theory (DFT) approach within the B3LYP/LANL2DZ/6-31G* framework to investigate the structural and bonding analysis of nickel group transition metal Carbonyls [M(CO)4] with terminal substituted tin chalcogenides Complexes [M(CO)3SnX] (M = Ni, Pd, and Pt; X = O, S, Se, and Te). The study optimises geometries, calculates vibrational frequencies, Electron localisation parameters, inherent charges, molecular orbitals, and natural bond orders (NBO) of Ni, Pd, Pt tetra carbonyl compounds (M(CO)4) and Tin chalcogenides (M(CO3(SnX)) 1–15. While the optimised structures display tetrahedral 18-electron configurations, M(CO)3(SnX) compounds depict significant dipole moments (1.47–3.03 Debye) and varied M-Sn and C–O bond lengths. Bonding analysis through NBO, WBI, and orbital contributions elucidates polarised M-Sn bonds and distinctive sigma donor behaviour of SnX. Molecular orbital analysis uncovers trends in stability based on energy gaps. Results of the energy decomposition analysis (EDA) reveals the values of ΔEelstat are higher than that of ΔEorb, thus, indicating that the bonds under study have more ionic character. The [Ni(CO)4] shows 60.13% ionic and 39.87% covalent contribution towards Ni-C bond. The findings contribute to understanding molecular structures, reactivity, and applications in diverse chemical domains.