Reactions of [Ru{C6H4(NH)2-1,2}(PPh3)3] with Group 6 metal carbonyls. Crystal structure and reactivity with diphosphines of the linear heterotrinuclear complex [Ru2Mo{µ-C6H4(NH)2-1,2}2(CO)6(PPh3)2]

Abstract

The compound [Ru{C₆H₄(NH)₂-1,2}(PPh₃)₃]1 reacts with the Group 6 metal carbonyls, [M(CO)₆], in hot aromatic solvents giving different reaction products according to the stability of the metal carbonyl: [Ru₂{µ-C₆H₄(NH)₂-1,2}(CO)₄(PPh₃)₂]2(M = Cr); [W(CO)₅(PPh₃)] and trans-[W(CO)₄(PPh₃)₂](M = W) and the dark brown [Ru₂Mo{µ-C₆H₄(NH)₂-1,2}₂(CO)₆(PPh₃)₂]3(M = Mo). The structure of 3 has been established from X-ray diffraction analysis. This compound reacts, in boiling toluene, with diphosphines (Ph₂P)₂X [X = CH₂(dppm) or C₄H₈(dppb)] to form [Ru₂Mo{µ-C₆H₄(NH)₂-1,2}₂(CO)₄-(diphosphine)₂](diphosphine = dppm 4 or dppb 5) and for X = C₂H₄(dppe) or C₃H₆(dppp) a mixture of [Mo(CO)₄(diphosphine)] and [Ru{C₆H₄(NH)₂-1,2}(CO)(diphosphine)] was obtained. The new trinuclear complexes have been characterised by elemental analysis and by spectroscopic (IR and NMR) methods.