Syntheses, reactivity studies and structural characterisation of triruthenium carbonyl methoxynitrido clusters containing phosphine ligands

The substitution reaction of the methoxynitrido cluster, [Ru-3(CO)(9)(mu(3) CO)(mu(3)-NOMe)] 1 with PPh3 affords both mono- and di-substituted products with the formulae [Ru-3(CO)(8)(mu(3)-CO)(mu(3)-NOMe)(PPh3)] 2 and [Ru-3(CO )(7)(mu(3-)CO)(mu(3)-NOMe)(PPh3)(2)] 3, respectively. When a bidentate phos phine such as bis(diphenylphosphino)methane (dppm) is used, [Ru-3(CO)(7)(mu (3)-CO)(mu(3)NOMe)(mu-dppm)] 4 is formed, in which the dppm ligand replaced two equatorial carbonyls from two adjacent Ru centres. Both clusters 3 and 4 are stable when heated, while vacuum pyrolysis of 2 yields a di-isocyana te fluster [Ru-3(CO)(8)(mu-NCO)(2)(PPh3)(2)] 5 with the two isocyanate liga nds spanning over the open Ru ... Ru edge on both sides of the Ru-3 plane. (C) 1999 Elsevier Science S.A. All rights reserved.