Crystal structures of four new iridium complexes, each containing a highly flexible carbodi-phos-phorane PCP pincer ligand.

Compound [Ir(CH)(CHP)]Cl or [Ir(cod)(CH(dppm)-κ,,)]Cl (), was obtained from [IrCl(cod)] and the carbodi-phospho-rane (CDP) salt [CH(dppm)]Cl [where cod = cyclo-octa-1,5-diene and dppm = bis-(di-phenyl-phosphino)methane]. Treatment of with thallium(I) tri-fluoro-methane-sulfonate [Tl(OTf)] and subsequent crystallization gave complex Ir(CH)(CHP)·CHCOCH·CHCl or Ir(cod)(CH(dppm)-κ,,)·CHCOCH·CHCl () [systematic name: (cyclo-octa-1,5-diene)(1,1,3,3,5,5,7,7-octa-phenyl-1,7-diphospha-3,5-di-phospho-niaheptan-4-yl)iridium(I) bis-(tri-fluoro-methane-sulfonate)-ethyl acetate-di-chloro-methane (1/1/1)]. This five-coordinate iridium(I) complex cation adopts a trigonal-bipyramidal geometry with the CDP carbon and one cod double bond in axial sites. Compound represents the first example of a non- coordination of the PCP pincer ligand [CH(dppm)] with a P-Ir-P angle of 98.08 (2)°. Compound , [IrClH(CHP)]·(CH)CO or [IrClH(C(dppm)-κ,,)]·(CH)CO [systematic name: di-chlorido-hydrido(1,1,3,3,5,5,7,7-octa-phenyl-1,5λ,7-triphospha-3-phospho-niahept-4-en-4-yl)iridium(III) acetone monosolvate], crystallizes as an acetone monosolvate. It is a six-coordinate Ir coordination compound. Here, the PCP pincer ligand is coordinated in a manner; one chlorido ligand is positioned to the carbon donor, the remaining two coordination sites being occupied by the second chlorido and a hydrido ligand to each other. Complex , [IrClH(CHP)]Cl·5HO or [IrClH(CH(dppm)-κ,,)]Cl·5HO [systematic name: di-chlorido-hydrido(1,1,3,3,5,5,7,7-octa-phenyl-1,7-diphospha-3,5-di-phospho-niaheptan-4-yl)iridium(III) chloride penta-hydrate], represents the conjugate CH acid of . The ligand [CH(dppm)] is coordinated in a manner. In the cationic six-coordinate Ir complex , [IrClH(CO)(CHP)]Cl·2CHOH·HO or [IrClH(CO)(C(dppm)-κ,,)]Cl·2CHOH·HO [systematic name: carbonyl-chlorido-hydrido(1,1,3,3,5,5,7,7-octa-phenyl-1,5λ,7-triphospha-3-phos-pho-niahept-4-en-4-yl)iridium(III) chloride-methanol-water (1/2/1)], the chlorido ligand is found in the plane defined by the Ir center and the PCP ligand; the H and CO ligands are positioned axially to this plane and to each other.