CO substitution in Ru3(CO)12 by 2,3-bis(diphenylphosphino)-N-phenyl-maleimide (bppm). X-ray diffraction structure of Ru2(CO)6(bppm)

The cluster Ru3(CO)12 reacts with the diphosphine ligand 2,3-bis(diphenylphosphino)-N-phenyl-maleimide (bppm) in toluene solution at 100○C by fragmentation to give a 2:1 mixture of the donor–acceptor complex Ru2(CO)6(μ-bppm) and the phosphido-bridged species Ru2(CO)6\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document} $$[\mu {\text{ - }}{\text{(O)](}}\mu _{\text{2}} {\text{ - PPh}}_{\text{2}} )$$ \end{document}, respectively. The new diruthenium compounds have been isolated by chromatography and characterized in solution by IR and NMR (1H and 31P) spectroscopies, in addition to X-ray diffraction analysis in the case of Ru2(CO)6( μ2 -bppm). Ru2(CO)6( μ2 -bppm), which exists as two crystallographically independent molecules in the unit cell, crystallizes in the orthorhombic space group Pbca, a = 18.8441(9), b = 21.352(2), c = 36.510(2) Å, V = 14,690(1) Å3, z = 16, Dcalc = 1.649 g/cm3; R = 0.0356, and Rw = 0.0812 for 17732 observed reflections. The reactivity of the bis(diphenylphosphino)-N-phenyl-maleimide ligand with Ru3(CO)12 under thermolysis conditions is contrasted with the related diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd).