The gas-phase-optimized geometry of newly synthesized and characterized diorganotin(IV) 2-chloridophenylacetohydroxamate complexes of composition [Me<sub>2</sub> Sn(HL)<sub>2</sub> ] (I) and [n-Bu<sub>2</sub> Sn(HL)<sub>2</sub> ] (II) (where KHL = potassium 2-chloridophenylacetohydroxamate (2-ClPhAHK); [Me<sub>2</sub> Sn(2-ClC<sub>6</sub> H<sub>4</sub> CH<sub>2</sub> CONHO)<sub>2</sub> ] (I) and [n-Bu<sub>2</sub> Sn(2-ClC<sub>6</sub> H<sub>4</sub> CH<sub>2</sub> CONHO)<sub>2</sub> ] (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 (CO, CN, and NO) of complexes with that of free ligand. The SnO bond lengths in complexes are suggestive of weak coordinate (through carbonyl CO) and strong covalent (through hydroxamic NO) bonding of the ligand. The magnitude of CSnC 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 <sup>1</sup> H NMR chemical shifts have substantiated the molecular structure of complexes. © 2019 Wiley Periodicals, Inc.