Crystal structures of two PCN pincer iridium complexes and one PCP pincer carbodi-phospho-rane iridium inter-mediate: substitution of one phosphine moiety of a carbodi-phospho-rane by an organic azide.

The structure of [Ir{(4-Cl-C6 H4 N3 )C(dppm)-κ3 P , C , N }(dppm-κ2 P , P ')]Cl·1.5CH2 Cl2 ·0.5C7 H8 (C57 H48 Cl2 IrN3 P4 ·1.5CH2 Cl2 ·0.5C7 H8 ) ( 2 ), dppm = bis-(di-phenyl-phosphino)methane {systematic name: [7-(4-chloro-phen-yl)-1,1,3,3-tetra-phenyl-5,6,7-tri-aza-κ N 7 -1,3λ4 -diphospha-κ P 1 -hepta-4,6-dien-4-yl][methyl-ene-bis(di-phenyl-phosphine)-κ2 P , P ']iridium(I) chloride-di-chloro-methane-toluene (2/3/1)}, resulting from the reaction of [IrClH{C(dppm)2 -κ3 P , C , P )(MeCN)]Cl ( 1a ) with 1-azido-4-chloro-benzene, shows a monocationic five-coordinate IrI complex with a distorted trigonal-bipyramidal geometry. In 2 , the iridium centre is coordinated by the neutral triazeneyl-idene-phospho-rane (4-Cl-C6 H4 N3 )C(dppm) acting as a PCN pincer ligand, and a chelating dppm unit. The structure of the coordination compound [IrCl(CN)H(C(dppm)2 -κ3 P , C , P )]·CH3 CN, (C52 H45 ClIrNP4 ·CH3 CN) ( 1b ) [systematic name: chlorido-cyanidohydrido(1,1,3,3,5,5,7,7-octa-phenyl-1,3λ5 ,5λ4 ,7-tetra-phospha-κ2 P 1 , P 7 -hept-3-en-4-yl)iridium(III) aceto-nitrile monosolvate], prepared from 1a and KCN, reveals an octa-hedral IrIII central atom with a meridional PCP pincer carbodi-phospho-rane (CDP) ligand; the chloride ligand is located trans to the central carbon of the CDP functionality while the hydrido and cyanido ligands are situated trans to each other. The chiral coordination compound [Ir(CN)((4-Cl-C6 H4 N3 )CH(CH(P(Ph)2 )2 )-κ3 P , C , N )(dppm-κ2 P , P ')]·2CH3 OH, (C58 H48 ClIrN4 P4 ·2CH3 OH) ( 3 ) (systematic name: {4-[3-(4-chloro-phen-yl)triazenido-κ N 3 ]-1,1,3,3-tetra-phenyl-1,3λ5 -diphospha-κ P 1 -but-2-en-4-yl}cyanido[methyl-enebis(di-phenyl-phosphine)-κ2 P , P ']iridium(III) methanol disolvate), formed via prolonged reaction of 1-azido-4-chloro-benzene with 1b , features a six-coordinate IrIII central atom. The iridium centre is coordinated by the dianionic facial PCN pincer ligand [(4-Cl-C6 H4 N3 )CH(CH(P(Ph2 )2 )2 )], a cyanido ligand trans to the central carbon of the PCN pincer ligand and a chelating dppm unit. Complex 2 exhibits a 2:1 positional disorder of the Cl- anion. The CH2 Cl2 and C7 H8 solvent mol-ecules show occupational disorder, with the toluene mol-ecule exhibiting additional 1:1 positional disorder with some nearly overlying carbon atoms.