The crystal and molecular structure of tetracarbonyl[diphenyl-2-(prop-cis-1-enyl)phenylphosphine]molybdenum(0), (Ph2PC6H4·CH:CH·Me)(CO)4Mo

Abstract

A three-dimensional X-ray crystal structure analysis has shown that the product obtained by replacement of norbornadiene in tetracarbonylnorbornadienemolybdenum by 2-allylphenyldiphenylphosphine is the compound tetracarbonyl[diphenyl-2-(prop-cis-1-enyl)phenylphosphine]molybdenum(0), the ligand having re-arranged.

Photographic measurements were made at 155°K. In a triclinic cell having a= 10·53, b= 13·26, c= 9·36 Å(10^–10 m), α= 100·2, β= 91·0, γ= 118·2°, and space group P, there are two molecules. The structure was solved from Patterson and electron-density difference syntheses and refined by least squares to R 0·09. The molybdenum atom is octahedrally co-ordinated by one phosphorus atom, Mo–P, 1·517 ± 0·005 Å, four carbonyl groups, Mo–C, 1·96–2·05, and by the olefin group, Mo–C, 2·45 and 2·52 ± 0·02 Å. Both carbon atoms of the olefin lie approximately in the plane containing their mid-point, and the molybdenum and phosphorus atoms; the C–C bond length is 1·39 ± 0·03 Å. The three P–C bonds average 1·84 ± 0·02 Å, the eighteen C–C bonds in the phenyl rings average 1·40 ± 0·03 Å, the four CO bonds average 1·14 ± 0·03 Å, the C–C bond from the olefin group to the terminal methyl group is 1·44 ± 0·03 Å and that to the phenyl ring is 1·51 ± 0·03 Å.