Incorporation of phenyl-substituted pentadienyl ligands in (pentamethylcyclopentadienyl)ruthenium complexes

Abstract

The reactions of the [Ru(C₅Me₅)Cl]₄ tetramer with 2,4-diphenylpenta-1,3-diene or 3-phenyl- or 1,5-diphenyl-substituted pentadienyl anions lead to the incorporation of the expected phenyl-substituted pentadienyl ligands into the respective symmetric Ru(C₅Me₅)(Pdl) products (Pdl = 2,4-Ph₂C₅H₅; 3-PhC₅H₆; 1,5-Ph₂C₅H₅). The reaction of the tetramer with a mixture of 2-methyl-4-phenylpenta(-1,3- or -2,4-)dienes led to the Pdl = 2-Me-4-PhC₅H₅ complex. In contrast, the reaction of the tetramer with 3-phenylpenta-1,3-diene led to simple incorporation of the η⁴-diene ligand. Structural confirmation of the formulations of the four η⁵-pentadienyl complexes has been achieved, allowing for a number of comparisons to be made regarding the structural effects of phenyl substitution on the (1,5), (2,4) and 3 positions of the open dienyl ligand.