The mechanism of formation and crystal structure of trans-dichlorotetrakis-(dimethylphosphine)ruthenium(II), RuCl2[PH(CH3)2]4

Abstract The title compound has been prepared by the reaction of tetramethylbiphosphine and ruthenium trichloride hydrate. When ethanol is present in the reaction medium it is oxidized to acetaldehyde; however, in the absence of ethanol the water of hydration is the source of hydrogen, as shown by incorporation of deuterium, introduced as D 2 0. The single crystal x-ray structural study demonstrates that the compound has a transoctahedral configuration as anticipated from proton nmr. Crystal data: space group, Pbca; a = 11.571(3) A, b = 12.133(2) A ; c = 12.831(4) A ; V = 1801.3(8) A, Z = 4. The molecule lies on a crystallographic inversion center and has the following metal-ligand bond lengths: Ru-P, 2.323(1) A , 2.331(1) A , RuCl, 2.440(1) A . The PC distances range from 1.837(7) A to 1.841(7) A , with a mean of 1.839 A .