DFT calculations on molecular structures, HOMO-LUMO study, reactivity descriptors and spectral analyses of newly...

The gas-phase-optimized geometry of newly synthesized and characterized diorganotin(IV) 2-chloridophenylacetohydroxamate complexes of composition [Me₂ Sn(HL)₂ ] (I) and [n-Bu₂ Sn(HL)₂ ] (II) (where KHL = potassium 2-chloridophenylacetohydroxamate (2-ClPhAHK); [Me₂ Sn(2-ClC₆ H₄ CH₂ CONHO)₂ ] (I) and [n-Bu₂ Sn(2-ClC₆ H₄ CH₂ CONHO)₂ ] (II) computed by B3LYP/6-311++G(d,p) method has shown these to be distorted octahedral. Bonding through carbonyl and hydroxamic oxygen atoms (O, O coordination) has been inferred from a comparison of computed important bond lengths (CO, CN, and NO) of complexes with that of free ligand. The SnO bond lengths in complexes are suggestive of weak coordinate (through carbonyl CO) and strong covalent (through hydroxamic NO) bonding of the ligand. The magnitude of CSnC bond angles involving two methyl/n-butyl groups is suggestive of cis-conformation at tin metal. The thermodynamic parameters (G, H, S, E, Cv, and U) of complexes have been computed. From the energies of frontier molecular orbitals (HOMO-LUMO), the reactivity descriptors, namely, ionization potential, electron affinity, chemical potential (μ), hardness (η), softness (S), electronegativity (χ), and electrophilicity index (ω) have been calculated. The computed vibrational frequencies and ¹ H NMR chemical shifts have substantiated the molecular structure of complexes. © 2019 Wiley Periodicals, Inc.