PREPARATION AND ISOMERISM OF BIS[MU-(TRIFLUOROMETHYL)PHOSPHIDO]-HEXACARBONYLDIIRON, FE2(CO)6[MU-P(CF3)(H)]2 - CRYSTAL-STRUCTURE OF THE TRANS ISOMER

Reaction of P(CF3)H2 with Fe2(CO)9 gives Fe(CO)4{P(CF3)H2), pyrolysis of which produces bis|μ-(trifluoromethyl)phosphido]-hexacarbonyldiiron, Fe2(CO)6{μ-P(CF3)(H)}2. The phosphido-bridged dimer exists in two isomeric forms. The trans isomer crystallizes in the triclinic space group P, with a=8.112 (2) Å, b=8.287 (3) Å, c=12.891 (2) Å, α=79.56 (1)°, β=80.88 (1)°, and γ=69.52 (2)°. The structure has been determined from 1906 X-ray counter intensities by Patterson and Fourier techniques and refined by full-matrix least-squares methods to R=7.40% (9.32% weighted). There is a direct interaction between the axial CF3 group and the axial H atom, seen both in the crystal structure and in the 19F NMR spectrum of a solution in CCl3F. © 1979, American Chemical Society. All rights reserved.