Crystal and molecular structure of 2,2′-bipyridyl-(μ₃-1-keto-2,3,4-triphenylcyclobutenyl) dicarbonylbromomolybdenum(1)benzene [(C₆H₅)₃C₃CO](C₁₀H₈N₂)(CO)₂MoBr·C₆H₆

Abstract

The crystal structure of [(C₆H₅)₃C₃CO](C₁₀H₈N₂)(CO)₂MoBr·C₆H₆ has been determined. The complex crystallizes in the triclinic space groupP ¯1 witha=8.52(1),b=19.42(3),c=10.54(1) Å, α=97.4(1), β=74.6(1), and γ=87.5(1)°. There are two formula units per cell. A total of 2924 unique observed reflections was collected photographically using CuKα radiation. The structure was refined toR=0.072. The molybdenum atom in this compound can be considered as situated at the center of a very distorted octahedron. The six coordination sites about the metal atom are occupied by two carbonyl groups which share with the bipyridyl the four equatorial positions. The bromine and a π-bonded keto-triphenylcyclobutenyl ring take up the two axial positions. There is an η³ interaction between the cyclobutenyl ring and the molybdenum atom. The detailed geometry of the 1-keto-2,3,4-triphenylcyclobutenyl ligand is similar to that found by Coffey (1962) in a cobalt complex. In the present compound the cyclobutenyl ring is slightly puckered with a dihedral angle of 11.05° between the plane which contains the allylic carbon atoms and that containing the ketonic group. Two solvating benzene molecules are centered at the inversion sites in the unit cell.