In this work, by using diphenylphosphonic acid as ligand and butyltin hydroxide oxide as tin source, reacting with nickel acetate and cobalt acetate respectively, two hexanuclear tin oxo clusters formulated as [(n-BuSn)₄ Ni₂(μ₃-O)₂(μ₃-OH)₂(CH₃COO)₄(Ph₂PO₂)₆] (1) and [(n-BuSn)₄Co₂(μ₃-O)₂(μ₃-OH)₂(CH₃COO)₄(Ph₂PO₂)₆] (2) were solvothermally synthesized. Both 1 and 2 were characterized by infrared spectroscopy, elemental analysis, and single-crystal X-ray diffraction. Spectral experiments revealed that the two complexes have absorptions in the visible region. The optical band gaps for complexes 1 and 2 are 1.90 and 1.79 eV, respectively. Complexes 1 and 2 exhibited photocatalytic CO₂ reduction activity, and only CO was generated, with rates of 10.01 and 26.89 μmol·g^-1·h^-1, respectively. CCDC: 2505024, 1; 2505025, 2.

A heterometallic Mn/Ti cluster formulated as [Ti₃Mn₂(Sal)₈(Phen)(CH₃CN)(H₂O)] (1) was solvothermally synthesized via the reaction of manganese acetate with a titanate precursor, using salicylic acid (H₂Sal) and 1, 10-phenanthroline (Phen) as organic ligands. By carefully tuning the reaction parameters and eliminating Phen from the reaction system, a structurally distinct heterometallic Mn/Ti cluster, [Ti₄Mn₄(Sal)₁₂(CH₃CN)₂]·(CH₃CN)₄ (2), was further isolated. The molecular structures of both complexes 1 and 2 were unambiguously established by elemental analysis, Fourier-transform infrared (FTIR) spectra, and single-crystal X-ray diffraction. Spectroscopic measurements demonstrated that both complexes feature prominent light absorption in the visible region, with the calculated optical band gaps of 1.93 eV for complex 1 and 2.15 eV for complex 2, respectively. Photocatalytic investigations revealed that complexes 1 and 2 exhibited efficient catalytic activity toward CO₂ reduction, affording CO as the exclusive carbon-containing product, with corresponding CO evolution rates of 7.21 and 14.39 μmol·g^-1·h^-1, respectively.