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

Abstract

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)Å, 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)Å. 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.