Synthesis, characterization and molecular structures of allenylidene, vinylidene–alkylidene complexes containing [CpOs(PPh3)2]+ fragment

The reaction of [CpOs(PPh3)2Br] with diphenylpropargylic alcohol HCCCPh2(OH) in the presence of ammonium hexafluorophosphate leads to the formation of cationic osmiumallenylidene complex [CpOs(CCCPh2)(PPh3)2][PF6] (1), but when the dimethylpropargylic alcohol HCCCMe2(OH) was used as a substrate, a dicationic diosmium vinylidene–alkylidene complex of the formula [(CpOs)2(μ-C10H12)(PPh3)4][PF6]2 (2) was obtained. The structures of these complexes have been determined by X-ray diffraction. Complex 1 crystallizes in monoclinic space group P21/c with a=13.4083(6) Å, b=19.5700(9) Å, c=20.3806(9) Å and β=100.3620(10)°. Complex 2 crystallizes in triclinic space group P1̄ with a=13.0396(11) Å, b=15.2420(13) Å, c=21.6406(19) Å and α=72.5290(10)°, β=75.1960(10)°, γ=85.6360(10)°.