Diphenylphosphinopyridine (PPh 2Py) versus 2-(2-diphenylphosphinomethyl)pyridine (PPh 2CH 2Py) in the coordination to ruthenium centres: Study of the reaction of PPh 2Py containing formato-bridged dinuclear Ru(I) complexes and PPh 2CH 2Py containing mononuclear formato Ru(II) complexes with dithioles

Abstract

Dinuclear carboxylato-bridged Ru(I) complexes [Ru 2(μ-RCOO) 2(CO) 4L 2] (L = RCOOH; R = H, Me) were reacted with diphenylphosphinopyridine (PPh 2Py) and 2-(2-diphenylphosphinomethyl)pyridine (PPh 2CH 2Py) ligands.In agreement with previously reported results, the reaction with PPh 2Py preserves the dinuclear structure of Ru(I) complexes [Ru 2(μ-RCOO) 2(CO) 4(PPh 2Py) 2] (R = H ( 1) and Me ( 2)).On the other hand, the reaction with PPh 2CH 2Py leads to the formation of mononuclear ionic Ru(II) complexes of the type [Ru(RCOO)(PPh 2CH 2Py)(CO) 2][RCOO] (R = H ( 3) and Me ( 4)).The reaction of 1 with HS(CH 2) n SH ( n = 2, 3) gives dinuclear dithiolato-bridged Ru(I) complexes [Ru 2(μ-S(CH) n S)(CO) 4(PPh 2Py) 2] ( n = 2 ( 5), 3 ( 6)).The equivalent reaction of HSCH 2CH 2SH with 3 forms the mononuclear neutral complex[Ru(S(CH 2) 2S)(CO) 2(PPh 2CH 2Py)] ( 7). These complexes were characterised by elemental analyses, IR, 1H, 13C and 31P NMR spectroscopies. Additional liquid mass (with electrospray) spectrometry was used for complexes 3 and 4.