Studies of metal-nitrogen multiple bonds. IV. The crystal and molecular structure of trichloro(methylimino)bis(diphenylethylphosphine)rhenium(V)

The crystal structure of the alkylimino rhenium(V) complex trichloro(methylimino) bis (diphenylethylphosphme)rhenium(V), ReCl₃(NCH₃)(P(C₆H₅)₂C₂H₅)₂, has been determined from three-dimensional X-ray data collected by counter methods and refined using least-squares techniques to a final R factor of 4.8% on F for the 2209 independent reflections above background. The material crystallizes in a monoclinic cell of dimensions α = 12.64 (3) Å, b = 17.85 (4) Å, c = 13.72 (3) Å, β = 101.30 (3)°, and space group C_2h⁵-P21/n. The density of 1.64 g/cm³ calculated for four formula units in the unit cell agrees well with the observed density of 1.63 ± 0.01 g/cm³. The coordination about the Re atom is distorted octahedral, with the phosphine ligands trans to one another, and Cl atoms trans to one another in the basal plane and with the third Cl at the one vertex and the methylimino group (coordinated to the Re atom via the N atom) at the other. The Re-P distances are 2.482 (7) and 2.486 (7) Å, the Re-Cl distances in the basal plane are 2.408 (6) and 2.428 (6) Å, and the Re-Cl distance trans to the N atom is 2.411 (6) Å. The Re-N distance is 1.685 (11) Å and the Re-N-CH₃ angle is close to linearity at 173°. The molecule as a whole is very similar to the aryliminorhenium complexes reported earlier.