Diphenylphosphinopyridine (PPh2Py) versus 2-(2-diphenylphosphinomethyl)pyridine (PPh2CH2Py) in the coordination to ruthenium centres: Study of the reaction of PPh2Py containing formato-bridged dinuclear Ru(I) complexes and PPh2CH2Py containing mononuclear formato Ru(II) complexes with dithioles

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