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(mu-RCOO)(2)(CO)(4)L-2] (L = RCOOH; R = H, Me) were reacted with diphenylphosphinopyridine (PPh2Py) and 2-(2-diphenylphosphinomethyl)pyridine (PPh2CH2PY) ligands. In agreement with previously reported results, the reaction with PPh2PY preserves the dinuclear structure of Ru(I)) complexes [Ru-2(mu-RCOO)(2)(CO)(4)(PPh2PY)(2)] R = H (1) and Me (2)). On the other hand, the reaction with PPh2CH2PY leads to the formation of mononuclear ionic Ru(II) complexes of the type [Ru(RCOO)(PPh2CH2Py)(CO)(2)][RCOO] (R = H (3) and Me (4)). The reaction of 1 with HS(CH2)(n)SH (n = 2, 3) gives dinuclear dithiolato-bridged Ru(I) complexes [Ru-2(mu-S(CH)(n)S)(CO)(4)(PPh2PY)(2)] (n = 2 (5), 3 (6)). The equivalent reaction of HSCH2CH2SH with 3 forms the mononuclear neutral complex [Ru(S(CH2)(2)S)(CO)(2)(PPh2CH2Py)] (7). These complexes were characterised by elemental analyses, IR, H-1, C-13 and P-31 NMR spectroscopies. Additional liquid mass (with electrospray) spectrometry was used for complexes 3 and 4. (c) 2005 Elsevier B.V. All rights reserved.