A library of platinum (II) complexes of general formula (O,O′-β-diketonate)PtLX (L = dimethylsulfoxide, pyridine, triphenylphosphine; X = chloride, γ-acetylacetonate) has been prepared, using synthetic methodologies available in the literature. The library has been supplemented with a novel platinum (II) complex bearing a triazenido N-oxide ligand. The complexes have been characterized and tested as precatalysts for the photoactivated curing of silicone resins. Correlations have been established between the nature of the employed ligands, the ultraviolet-visible (UV-Vis) absorption spectrum of the complexes and their catalytic performance, which enable the tailored preparation of complexes with improved performance in view of possible technological applications.