Photodriven Elimination of Chlorine From Germanium and Platinum in a Dinuclear Pt^II→Ge^IV Complex

Searching for a connection between the two-electron redox behavior of Group-14 elements and their possible use as platforms for the photoreductive elimination of chlorine, we have studied the photochemistry of [(o-(Ph₂P)C₆H₄)₂Ge^IVCl₂]Pt^IICl₂ and [(o-(Ph₂P)C₆H₄)₂ClGe^III]Pt^IIICl₃, two newly isolated isomeric complexes. These studies show that, in the presence of a chlorine trap, both isomers convert cleanly into the platinum germyl complex [(o-(Ph₂P)C₆H₄)₂ClGe^III]Pt^ICl with quantum yields of 1.7 % and 3.2 % for the Ge^IV–Pt^II and Ge^III–Pt^III isomers, respectively. Conversion of the Ge^IV–Pt^II isomer into the platinum germyl complex is a rare example of a light-induced transition-metal/main-group-element bond-forming process. Finally, transient-absorption-spectroscopy studies carried out on the Ge^III–Pt^III isomer point to a ligand arene–Cl^. charge-transfer complex as an intermediate.