The crystal and molecular Structure of Trans‐MoCl 3 (C 5 H 5 N) 3

Trans‐MoCl 3 Py 3 (Py 7mdash; pyridine) crystallizes in the monoclinic space group P2 1 /c with four molecules in the unit cell. The cell dimensions are: a = 9.229(3), b = 12.555(3), c = 17.920(4) Å and β = 119.33(2)°. Calculated density for Z = 4 is 1.61 gcm −3 and measured 1.61 ± 0.02 gcm −3 . Structure has been solved from 1594 independent film data and refined to the conventional R factor 9.1%. Three chlorine atoms and three nitrogen atoms of the pyridine molecules form an octahedral coordination about molybdenum in the 1, 2,6 or trans configuration. Distances within octahedron are: MoCl 2.437(5), 2.424(5), 2.423(5) Å, and MoN(pyridine) 2.189(13), 2.163(15), 2.223(15) Å. CrCl 3 Py 3 , CrBr 3 Py 3 and MoBr 3 Py 3 crystallize in the same space group with comparable cell dimensions and are probably isostructural with trans‐MoCl 3 Py 3 .