Studies of Metal-Nitrogen Multiple Bonds. II. The Crystal and Molecular Structure of Nitridodichlorobis(Triphenylphosphine)Rhenium(V), ReNCl₂(P(C₆H₅)₃)₂

The crystal and molecular structure of nitridodichlorobis(triphenylphosphme)rhemum(X7), ReNCl₂(P(C₅H₅)₃)₂ has been determined from three-dimensional X-ray data collected by counter methods. The structure has been refined by leastsquares techniques down to a final R factor of 4.8%, on F. The material crystallizes in space group C_2h⁶-I2/a of the monoclinic system, with four molecules in a cell of dimensions a = 15.71, b = 9.53, c = 22.17 A; β = 103° 26’. The crystal structure is made up of well-separated monomeric molecular units. Twofold crystallographic symmetry is imposed on the molecule. The inner coordination about Reis distorted from both idealized five-coordinate geometries: the trigonal bipyramid and the tetragonal pyramid. Roughly the structure may be described as a distorted tetragonal pyramid, with N at the apex and with the P atoms moved out of the basal plane of the Cl atoms toward the Re. The Re-Cl, Re-P, and Re-N distances are 2.377 ± 0.002, 2.448 ± 0.002, and 1.603 ± 0.009 A. Although the Re-Cl and Re-X distances differ markedly from those found in the closely related six-coordinated Re(V) complex, ReNCl₂(P(C₂H₅)₂C₆H₅)₃), the nonbonded interligand distances in the two compounds are very similar.