Crystal and molecular structure of 1,1,1,1-tetracarbonyl-2,2-bis(η-cyclopentadienyl-bis(µ-diphenylphosphido)-molybdenumzirconium, [(cp)2Zr(µ-PPh2)2-Mo(CO)4]

Abstract

The compound [(cp)₂Zr(µ-PPh₂)₂Mo(CO)₄](1), where cp =η-C₅H₅, has been prepared and characterised by a single-crystal X-ray diffraction study. The crystals are monoclinic, space group P2₁/c, Z= 4, with a= 17.506(9), b= 14.607(8), c= 14.887(11)Å, and β= 104.0(1)°. 3 715 Independent reflections above background have been measured on a diffractometer and the structure refined to R 0.069. The discrete molecules have approximate C_2v symmetry. The µ-PPh₂ groups bridge symmetrically across the (cp)₂Zr and Mo(CO)₄ moieties forming an approximately planar four-membered ring [Zr–P–Mo–P–], with the basic geometries about zirconium being tetrahedral and about molybdenum octahedral. The Zr ⋯ Mo distance of 3.290(1)Å signifies the presence of a single donor–acceptor bond Mo⁰→ Zr^IV thereby conferring a formal 18-electron closed-shell electronic configuration upon both metal centres. Dimensions of the bridge are Zr–P 2.61 8(3) and 2.631 (3), Mo–P 2.543(3) and 2.536(3)Å, P–Zr–P 98.5(1), and P–Mo–P 103.1(1)°. The Zr–P–Mo angles are 79.2(1) and 79.1(1)°.