The crystal structure of the second polymorph of dinitrosylbis(dimethyl phenylphosphonite)manganese(I) chloride, [Mn(NO)2{(P(OCH3)2C6H5}2Cl], has been determined by x-ray diffraction. This form crystallizes from C2H5OH/CH2C12 in the triclinic space group Pi, with a = 15.727 (5) Å, b = 15.198 (5) Å, c = 9.405 (5) Å, α = 90.97 (5)°, β = 89.04 (5) °, γ = 97.21 (5)°, V = 2229.6 Å 3, pobsd = 1.45 g cm-3, and Z = 4 (two molecules per asymmetric unit). The structure was solved by direct methods and refined by block-diagonal least squares to a conventional R of 0.040 for 3711 reflections with I > 1,65σ(I). The coordination about the manganese is trigonal bipyramidal in both molecules; however, the relative conformation of phosphonite ligands in the two molecules is not the same. One molecule has symmetry 2, while the other has symmetry m. In both isomers the NO groups are ordered, and the atoms of the |Mn(NO)2Cl) groups are coplanar with the two NO groups bent in toward each other. Bond lengths and angles of interest are as follows. Molecule [Formulla Omitted]. © 1979, American Chemical Society. All rights reserved.
