The Bonding of Molecular Nitrogen. III. The Crystal and Molecular Structure of Chlorodinitrogentetrakis(dimethylphenylphosphine)rhenium(I)

The crystal and molecular structure of the molecular nitrogen complex chlorodinitrogentetrakis(dimethylphenylphosphine)-rhenium(I), ReCl(N₂)(P(CH₃)₂C₆H₅)₄, has been determined from three-dimensional X-ray data collected by counter techniques. The central rhenium atom is octahedrally coordinated to four phosphorus atoms, to the chlorine atom, and to a nitrogen atom of the molecular nitrogen group. The chlorine and nitrogen atoms are trans. The Re-Cl bond distance is 2.521 (4) Å, the Re-N bond distance is 1.97 (2) Å, and the four Re-P bond distances have a menn value of 2.422 (10) Å. The molecular nitrogen group is linear with an Re-N-N bond angle of 177 (1)° and a Cl-Re-N bond angle of 175.6 (4)°. Owing to partial disorder between the chlorine atom and the molecular nitrogen entity, a precise determination of the N-N distance has not been possible. Crystal data are as follows: triclinic, space group C_i¹-P1; a = 12.730 (6) Å, b = 12.771 (6) Å, c = 11.523 (6) Å, α = 103.25 (3)°, β = 103.96 (2)°, γ = 95.37 (2)° (temperature 22°), Z = 2; d_obsd = 1.57 (3) g/cm³, d_calcd = 1.53 g/cm³. The structure was refined using 1968 independent reflections for which F₂ > 3σ(F²) and the refinement converged to a conventional R factor (on F) of 3.7%.