Synthesis and Characterization of Platinasilsesquioxane Complexes and Their Reaction with Arylboronic Acid

Phenyl(iodo)platinum complexes having a 2,2'-bipyridine (bpy) or 1,2-bis(diphenylphosphino)ethane (dppe) ligand react with incompletely condensed silsesquioxane (c-C5H9)(7)Si7O9(OH)(3) in the presence of Ag2O to yield platinasilsesquioxane complexes [Pt{(c-C5H9)(7)Si7O10(OH)(2)}(C6H5)(L)] (1, L = bpy; 2, L = dppe). NMR spectroscopy revealed their square-planar structures with an O-coordinated silsesquioxanate ligand and O-H center dot center dot center dot O hydrogen bonds within the ligand. Both complexes undergo transmetalation of p-methoxy-phenylboronic acid to afford unsymmetrical diarylplatinum complexes [Pt(C6H4OCH3-p(C6H5)(L)] (3, L = bpy; 4, L = dppe).