The Reactivity of Phosphanylphosphinidene Complexes of Transition Metals Toward Terminal Dihaloalkanes

[Image: see text] The reactivities of phosphanylphosphinidene complexes [(DippN)(2)W(Cl)(η(2)-P–PtBu(2))](−) (1), [(pTol(3)P)(2)Pt(η(2)-P=PtBu(2))] (2), and [(dppe)Pt(η(2)-P=PtBu(2))] (3) toward dihaloalkanes and methyl iodide were investigated. The reactions of the anionic tungsten complex (1) with stochiometric Br(CH(2))(n)Br (n = 3, 4, 6) led to the formation of neutral complexes with a tBu(2)PP(CH(2))(3)Br ligand or neutral dinuclear complexes with unusual tetradentate tBu(2)PP(CH(2))(n)PPtBu(2) ligands (n = 4, 6). The methylation of platinum complexes 2 and 3 with MeI yielded neutral or cationic complexes bearing side-on coordinated tBu(2)P–P-Me moieties. The reaction of 2 with I(CH(2))(2)I gave a platinum complex with a tBu(2)P—P—I ligand. When the same dihaloalkane was reacted with 3, the P—P bond in the phosphanylphosphinidene ligand was cleaved to yield tBu(2)PI, phosphorus polymers, [(dppe)PtI(2)] and C(2)H(4). Furthermore, the reaction of 3 with Br(CH(2))(2)Br yielded dinuclear complex bearing a tetraphosphorus tBu(2)PPPPtBu(2) ligand in the coordination sphere of the platinum. The molecular structures of the isolated products were established in the solid state and in solution by single-crystal X-ray diffraction and NMR spectroscopy. DFT studies indicated that the polyphosphorus ligands in the obtained complexes possess structures similar to free phosphenium cations tBu(2)P(+)=P−R (R = Me, I) or (tBu(2)P(+)=P)(2).