Further examples of unbalanced packing of chiral molecules and the crystal and molecular structure of tris(triphenylphosphine)nitrosyl-iridium

Crystals of CuCIL3, CuBrL3, and Ir(NO)L3, isomorphous with the trigonal polymorph of Pt(CO)L3(L = PPh3), represent further examples of unbalanced packing of chiral molecules. The structure of Ir(NO)(PPh3)3 has been fully determined from 1929 independent reflexions measured by counter methods. This complex crystallizes in space group P3 and has a unit cell of dimensions: a= 19·94(1), and c= 10·780(5)A, with Z= 3. The structure has been refined by full matrix least-squares to a final R of 0·0475. The absolute configuration of the crystal sample has been determined unambiguously and designated R,S,S. The three independent molecules present in the unit cell each possess C3 symmetry and display almost the same conformation. The Ir–N, Ir–P, and N–O bond lengths are 1·67(2), 2·31(1), and 1·24(3)A. The N–Ir–P and P–Ir–P angles are 116·8(5) and 101·3(6)°; there is indirect evidence of linearity in the Ir–N–O interaction.