Intermediates for methyl carbon-hydrogen activation in binuclear dimethylfulvene ruthenium carbonyl complexes

Abstract The methyl C H bonds in the dimethylfulvene complex [η 5 ,η 1 -C 5 H 4 C(CH 3 ) 2 ][Ru(CO) 2 ][Ru(CO) 4 ] are known experimentally to be activated by the central Ru 2 unit to give the dehydrogenation product [η 5 ,η 3 -C 5 H 4 C(CH 2 ) 2 ][Ru(CO) 2 ][Ru(CO) 3 ]. The mechanistic aspects of this process are explored by a theoretical investigation of the two series of complexes [C 5 H 4 C(CH 3 ) 2 ]Ru 2 (CO) n and [C 5 H 4 C(CH 2 ) 2 ]Ru 2 (CO) n ( n  = 6, 5, 4). Potential reaction intermediates with agostic hydrogen atoms as well as ruthenium carbonyl hydrides and dihydrogen complexes are found.