Triruthenium clusters bearing bridging dppm and capping sulfido ligands: X-ray structures of [Ru-3(CO)(6)(mu(3)-CO)(mu(3)-S)(PPh3)(mu-dppm)] and [Ru-3(CO)(6)(mu(3)-S)(2)(PPh3)(mu-dppm)]

摘要

Treatment of [Ru-3(CO)(10)(mu-dppm)] (1) with PPh3=S at ambient temperature in THF gave the known compound [Ru-3(CO)(7)(mu(3)-CO)(mu(3)-S)(mu-dppm)] (2) and the new compound [Ru-3(CO)(6)(mu(3)-CO)(mu(3)-S)(PPh3)(mu-dppm)] (3). Compound 3 can also be prepared by the room temperature reaction of 2 with PPh3 in the presence of Me3NO. A similar reaction of [Ru-3(CO)(7)(mu(3)-S)(2)(mu-dppm)] (4) with PPh3 afforded (3), [Ru-3(CO)(6)(mu(3)-S)(2)(PPh3)(mu-dppm)] (5) together with the previously reported compound [(mu-H)(2)Ru-3(CO)(7)(mu(3)-S)(mu-dppm)] (6). In contrast, a similar treatment of the sulfur-selenium compound [Ru-3(CO)(7)(mu(3)-S)(mu(3)-Se)(mu-dppm)] (7) with PPh3 afforded only [Ru-3(CO)(6)(mu(3)-S)(mu(3)-Se)(PPh3)(mu-dppm)] (8). Both compounds 5 and 8 exist as two isomers in solution, arising from the reversible migration of a metal-metal bond, induced by the dppm ligand. The reaction of 6 with PPh3 under the same conditions gave [(mu-H)(2)Ru-3(CO)(6)(mu(3)-S)(PPh3)(mu-dppm)] (9). Protonation of 4 and 7 by trifluoroacetic acid gave the mono-protonated species [(mu-H)Ru-3(CO)(7)(mu(3)-S)(2)(mu-dppm)](+) (10) and [(mu-H)Ru-3(CO)(7)(mu(3)-Se)(mu(3)-S)(mu-dppm)](+) (11), respectively, isolated as their PF6 salts. All the compounds have been characterized by spectroscopic data together with single crystal X-ray diffraction studies for 3 and 5. (C) 2005 Elsevier Ltd. All rights reserved.