Heteronuclear cluster systems. Part 13. Synthesis of µ-diphenyl-phosphido-bridged carbonylmetal complexes, and crystal structure of 1,2-µ-carbonyl-1,1,2,2,3,3-hexacarbonyl-1,3;2,3-bis-µ-diphenylphos-phido-triangulo-tricobalt

Abstract

Reaction of PPh₂Cl with Li[Co₃(CO)₁₀] or [Co₂(CO)₈] gives the new complex [Co₃(CO)₆(µ-CO)(µ-PPh₂)₂] and the known complex [{Co(CO)₃(µ-PPh₂)}₂]. Both reactions appear to proceed via the intermediate species [Co(CO)₄(PPh₂)] which may be trapped using [Fe₂(CO)₉] as [CoFe(CO)₇(µ-PPh₂)]. The crystal structure of the title complex has been determined by three-dimensional X-ray diffraction using MO-K_α radiation: a= 19.271(16), b= 11 .870(3). c= 13.512(8)Å, β= 99.36 °, Z= 4, space group P2₁/a, R= 0.069 7. The three cobalt atoms form an isosceles triangle, two sides of which are bridged by PPh₂ groups (one symmetrically, the other asymmetrically) and the third side also unequally by a carbonyl group.