Heterobinuclear nitrosyl complexes. Part 2. Crystal structures of [(Ph3P)2(NO)Ir(µ-dppn)(µ-Cl)PdCl][PF6]2 and [(Ph3P)Cl2Ir(µ-NO)(µ-dppn)PdCl]PF6[dppn = 3,6-bis(2′-pyridyl)pyridazine]

Abstract

From the reactions of [Ir(NO)(dppn)(PPh₃)₂][PF₆]₂ or [Ir(NO)(dppn)Cl(PPh₃)₂]PF₆ with [PdCl₂(NCPh)₂] the binuclear complexes [(Ph₃P)₂(NO)Ir(µ-dppn)(µ-Cl)PdCl][PF₆]₂(3) and [(Ph₃P)Cl₂Ir(µ-NO)(µ-dppn)PdCl]PF₆(5) respectively have been obtained. The structure of both these complexes have been determined by X-ray diffraction methods. Crystals of (3) are monoclinic, space group P2₁/a, with a= 22.365(9), b= 14.383(7), c= 18.525(7)Å, β= 115.17(2)°, and Z= 4. Crystals of (5) are monoclinic, space group Pn, with a= 15.754(7), b= 8.870(5), c= 14.453(7)Å, β= 111.42(2)°, and Z= 2. The structures have been solved from diffractometer data by Patterson and Fourier methods and refined by full-matrix least squares to R= 0.078 for 2 973 observed reflections for (3) and to R= 0.040 for 2 533 observed reflections for (5). In complex (3) a terminal bent NO group is bound to the Ir atom [Ir–N–O 123(3)°] with the dppn ligand and one Cl atom bridging the two metals [Ir ⋯ Pd separation 3.681 (4)Å]. In (5) the dppn ligand and the nitrosyl group bridge the two metals, with Ir–N (nitrosyl) bond distances of 2.030(15) and 1.953(17)Å. The Ir ⋯ Pd separation is of 3.327(2)Å. According to these structural features the reaction scheme involving the heterobinuclear dppn nitrosyl complexes has been redesigned.