Cluster chemistry: LXXXI. Reactions of Ru 3(μ-dppm)(CO) 10 with C 2(CO 2Me) 2. X-ray structures of Ru 3{μ 3-C 4(CO 2Me) 4}(μ-dppm)(CO) 6, Ru 3(μ-H) 2{μ 3-C 2(CO 2Me) 2}(μ-dppm)(CO) 7 and Ru 4(μ 3-H){μ-C 2(CO 2Me) 2}{μ-PPh 2CH 2PPh(C 6H 4)}(CO) 9

Abstract

Several complexes have been obtained from reactions between Ru 3(μ-dppm)(CO) 10 and C 2(CO 2Me) 2, including Ru 3{μ 3-C 2(CO 2Me) 2}(μ-dppm)(μ-CO)(CO) 7 (7), Ru 3{μ 3-C 4(CO 2Me) 4}(μ-dppm)(CO) 6, ( 8), Ru 4(μ 4-C 2)(CO 2Me) 2}(μ-dppm)(CO) 10 ( 11) and Ru 4(μ 3-H){μ 4-C 2(CO 2Me) 2}{μ-PPh 2CH 2PPh(C 6H 4)}(CO) 9 ( 10). A complex related to 10, containing a C 4(CO 2Me) 4 ligand, was obtained directly from Ru 3(μ 3-PPhCH 2PPh(C 6H 4)}(CO) 9 and the alkyne. Ready replacement of CO by 2H occurred in the reaction of 7 with H 2, which afforded Ru 3(μ-H) 2{μ 3-C 2(CO 2Me) 2}(μ-dppm)(CO) 7 ( 9). Complexes 8, 9 and 10 were characterised by single-crystal X-ray studies: in 8, the C 4(CO 2Me) 4 ligand forms a ruthenacyclopentadiene system which interacts in the η 4 mode with the second Ru atom, and via an ester CO group with the third Ru atom. In 9, the alkyne is attached to the Ru 3 cluster in the μ 3-η 2-|| mode, while in 10, it is incorporated into an octahedral C 2Ru 4 cluster; the metallated dppm ligand bridges an edge of one of the wings of the Ru 4 butterfly. Complexes 10 and 11 were obtained in only 1% and 2% yield, respectively.