Synthesis, characterization, computational studies, and reactivity of platinum(II) complexes of alkyl phosphite ligands

Abstract

Air-stable phosphite-ligated platinum complexes of the form cis-Pt(P(OR)3)2Cl2 and cis-Pt(P(OR)3)2Me2 based on five small alkyl phosphite ligands have been synthesized and characterized. The crystal structures for several of these species are reported, allowing for comparison between spectroscopic and structural parameters. Michaelis-Arbuzov-type dealkylation during synthesis was observed for some of the phosphite ligands, and a dealkylated product was structurally characterized. Density Functional Theory (DFT) and Quantum Theory of Atoms in Molecules (QTAIM) was also used to examine the electronic structure of the phosphite compounds. The QTAIM results support the increased π-acidity of the phosphite ligands compared to analogous phosphines. Thermolysis experiments were performed to examine the stability and reactivity of Pt(P(OR)3)2X2 species. It was found that coordinated P(OiPr)3 ligands decompose via cyclometallation and propylene extrusion.