The structure of [Ir{(4-Cl-C6H4N3)C(dppm)-κ3P,C,N}(dppm-κ2P,P′)]Cl·1.5CH2Cl2·0.5C7H8 (C57H48Cl2IrN3P4·1.5CH2Cl2·0.5C7H8) (2), dppm = bis­(di­phenyl­phosphino)methane {systematic name: [7-(4-chloro­phen­yl)-1,1,3,3-tetra­phenyl-5,6,7-tri­aza-κN7-1,3λ4-diphospha-κP1-hepta-4,6-dien-4-yl][methyl­ene­bis(di­phenyl­phosphine)-κ2P,P′]iridium(I) chloride–di­chloro­methane–toluene (2/3/1)}, resulting from the reaction of [IrClH{C(dppm)2-κ3P,C,P)(MeCN)]Cl (1a) with 1-azido-4-chloro­benzene, shows a monocationic five-coordinate IrI complex with a distorted trigonal–bipyramidal geometry. In 2, the iridium centre is coordinated by the neutral triazeneyl­idene­phospho­rane (4-Cl-C6H4N3)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-κ3P,C,P)]·CH3CN, (C52H45ClIrNP4·CH3CN) (1b) [systematic name: chlorido­cyanidohydrido(1,1,3,3,5,5,7,7-octa­phenyl-1,3λ5,5λ4,7-tetra­phospha-κ2P1,P7-hept-3-en-4-yl)iridium(III) aceto­nitrile monosolvate], prepared from 1a and KCN, reveals an octa­hedral IrIII central atom with a meridional PCP pincer carbodi­phospho­rane (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-C6H4N3)CH(CH(P(Ph)2)2)-κ3P,C,N)(dppm-κ2P,P′)]·2CH3OH, (C58H48ClIrN4P4·2CH3OH) (3) (systematic name: {4-[3-(4-chloro­phen­yl)triazenido-κN3]-1,1,3,3-tetra­phenyl-1,3λ5-diphospha-κP1-but-2-en-4-yl}cyanido[methyl­enebis(di­phenyl­phosphine)-κ2P,P′]iridium(III) methanol disolvate), formed via prolonged reaction of 1-azido-4-chloro­benzene with 1b, features a six-coordinate IrIII central atom. The iridium centre is coordinated by the dianionic facial PCN pincer ligand [(4-Cl-C6H4N3)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 CH2Cl2 and C7H8 solvent mol­ecules show occupational disorder, with the toluene mol­ecule exhibiting additional 1:1 positional disorder with some nearly overlying carbon atoms.

The structure of [Ir{(4-Cl-C6H4N3)C(dppm)-κ3 P,C,N}(dppm-κ2 P,P')]Cl·1.5CH2Cl2·0.5C7H8 (C57H48Cl2IrN3P4·1.5CH2Cl2·0.5C7H8) (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-κN 7-1,3λ4-diphospha-κP 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-C6H4N3)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)]·CH3CN, (C52H45ClIrNP4·CH3CN) (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-C6H4N3)CH(CH(P(Ph)2)2)-κ3 P,C,N)(dppm-κ2 P,P')]·2CH3OH, (C58H48ClIrN4P4·2CH3OH) (3) (systematic name: {4-[3-(4-chloro-phen-yl)triazenido-κN 3]-1,1,3,3-tetra-phenyl-1,3λ5-diphospha-κP 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-C6H4N3)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 CH2Cl2 and C7H8 solvent mol-ecules show occupational disorder, with the toluene mol-ecule exhibiting additional 1:1 positional disorder with some nearly overlying carbon atoms.

The common feature of the four iridium(III) salt complexes, (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ4P,C,C′,P′)chloridohydridoiridium(III) chloride methylene chloride 2.75-solvate (4), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ4P,C,C′,P′)chlorido(ethoxyoxoethanido)iridium(III) chloride–methanol–water (1/1/0.5) (5), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ4P,C,C′,P′)dichloridoiridium(III) chloride–methanol–water (1/1/2) (6) and (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ4P,C,C′,P′)carbonyl(ethoxyoxoethanide)iridium(III) dichloride–methylene chloride–water (1/2/1.5) (7) or in terms of their formulae [Ir(C55H50O2P4)ClH]Cl·2.75CH2Cl2 (4), [Ir(C4H7O2)(C55H50O2P4)Cl]Cl·CH3OH·0.5H2O (5), [Ir(C55H50O2P4)Cl2]Cl·CH3OH·2H2O (6) and [Ir(C4H7O2)(C55H50O2P4)(CO)]Cl2·2CH2Cl2·1.5H2O (7) is a central IrIII atom coordinated in a distorted octahedral fashion by a PCCP ligand system and two additional residues, such as chlorides, a hydride, a carbonyl or an alkyl unit. Thereby, the PCP pincer ligand system and the residue trans to the carbodiphosphorane (CDP) C atom surround the iridium(III) transition metal in the equatorial plane under the formation of two five-membered dissimilar chelate rings [C—CCDP—P (4, 5, 6 and 7) for the first ring: 120.2 (3), 121.9 (5), 111.2 (3) and 121.7 (2) °; for the second ring: 112.1 (3), 113.5 (5), 120.5 (3) and 108.3 (2)°]. A cyclopropane-like heterocycle is positioned approximately orthogonal (84.21–88.85°) to the equatorial plane, including an alkylidene bridge connecting the IrIII atom and the coordinating CDP atom of the PCP subunit. In general, the neutral PCCP ligand system coordinates the metal in a tetradentate way via three Lewis acid/base bonds and by an alkylidene unit presenting strengthened interactions. In all the crystal structures, (disordered) solvent molecules are present in the voids of the packed molecules that interact with the positively charged complex and its chloride counter-ion(s) through weak hydrogen bonding.

The common feature of the four iridium(III) salt complexes, (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-kappa P-4,C,C',P')chloridohydridoiridium(III) chloride methylene chloride 2.75-solvate (4), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-kappa P-4,C,C',P')chlorido(ethoxyoxoethanido)iridium(III) chloride-methanol-water (1/1/0.5) (5), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-kappa P-4,C,C',P')dichloridoiridium(III) chloride-methanol-water (1/1/2) (6) and (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-kappa P-4,C,C',P')carbonyl(ethoxyoxoethanide)iridium(III) dichloride-methylene chloride-water (1/2/1.5) (7) or in terms of their formulae [Ir(C55H50O2P4)ClH]Cl center dot 2.75CH(2)Cl(2) (4), [Ir(C4H7O2)(C55H50O2P4)Cl]Cl center dot CH3OH center dot 0.5H(2)O (5), [Ir(C55H50O2P4)Cl-2]Cl center dot CH3OH center dot 2H(2)O (6) and [Ir(C4H7O2)(C55H50O2P4)(CO)]Cl-2 center dot 2CH(2)Cl(2)center dot 1.5H(2)O (7) is a central IrIII atom coordinated in a distorted octahedral fashion by a PCCP ligand system and two additional residues, such as chlorides, a hydride, a carbonyl or an alkyl unit. Thereby, the PCP pincer ligand system and the residue trans to the carbodiphosphorane (CDP) C atom surround the iridium(III) transition metal in the equatorial plane under the formation of two five-membered dissimilar chelate rings [C-CCDP-P (4, 5, 6 and 7) for the first ring: 120.2 (3), 121.9 (5), 111.2 (3) and 121.7 (2)degrees; for the second ring: 112.1 (3), 113.5 (5), 120.5 (3) and 108.3 (2)degrees]. A cyclopropane-like heterocycle is positioned approximately orthogonal (84.21-88.85 degrees) to the equatorial plane, including an alkylidene bridge connecting the IrIII atom and the coordinating CDP atom of the PCP subunit. In general, the neutral PCCP ligand system coordinates the metal in a tetradentate way via three Lewis acid/base bonds and by an alkylidene unit presenting strengthened interactions. In all the crystal structures, (disordered) solvent molecules are present in the voids of the packed molecules that interact with the positively charged complex and its chloride counter-ion(s) through weak hydrogen bonding.

The structure of [IrCl2(C58H51N3P4)]Cl center dot 5.5CH(3)CN or [IrCl2(NHCHPh)-(((dppm)C(N(2)dppm))-kappa P-3, C,P)]Cl center dot 5.5CH(3)CN [3, dppm = bis (diphenylphosphino)methane; systematic name: dichlorido(1,1,3,3,7,7,9,9-octaphenyl-4,5-diaza-1,3 lambda(5),7 lambda(4) ,9-tetraphosphanona-3,5-dien-6-yl-kappa P-2(1) ,P-9)(phenylmethanimine-kappa N)iridium(III) chloride acetonitrile hemihendecasolvate], resulting from an oxygen-mediated cleavage of a triazeneylidenephosphorane ligand producing a diazomethylenephosphorane and a nitrene moiety, which in turn rearrange via a Staudinger reaction and a 1,2-hydride shift to the first title complex, involves a six-coordinate Ir-III complex cation coordinated by a facial PCP pincer ligand, a benzaldimine and two chlorido ligands. The pincer system features a five- and a seven-membered ring, with the central divalent carbon of the PCP pincer ligand being connected to a phosphine and a diazophosphorane. The chlorido ligands are positioned trans to the central carbon atom and to the phosphorus donor of the seven-membered ring of the pincer system, respectively. A chloride ion serves as counter-ion for the monocationic complex. The structure of [IrI(C26H22N2P2)(C26H22P2)(C6H7N)]I(I-3)center dot 0.5I(2)center dot CH3OH center dot 0.5CH(2)Cl(2) or [IrI(NHCHPh)((dppm)C(N-2)-kappa P-2, C)(dppm-kappa P-2,P')]I(I-3)center dot 0.5I(2)center dot CH3OH center dot 0.5CH(2)Cl(2) {4, systematic name: (4-diazo-1,1,3,3,-tetrapheny1-1,3 lambda(4)-diphosphabutan-4-yl-kappa P-1)iodido [methylenebis(diphenylphosphine)-kappa(2) P,P'] (phenylmethanimine-kappa N)iridium(III) iodide-triiodide-dichloromethane-iodine-methanol (2/2/1/1/2)], accessed via treatment of the triazeneylidenephosphorane complex [Ir((BnN3)C(dppm)-kappa P-3,C,N)(dppm-kappa(2) P,P')]Cl with hydroiodic acid, consists of a dicationic six-coordinate Ir-III complex, coordinated by a bidentate diazomethylenephosphorane, a benzaldimine, a chelating dppm moiety and an iodido ligand. The phosphorus atoms of the chelating dppm are trans to the central carbon atom of the diazomethylenephosphorane and the iodide ligand, respectively. Both an iodide and a triiodide moiety function as counter-ions. The acetonitrile solvent molecules in 3 are severely disordered in position and occupation. In 4, the I(3)(- )anion is positionally disordered (ratio roughly 1:1), as is the I- anion with a ratio of 9:1. The dichloromethane solvent molecule lies near a twofold rotation axis (disorder) and was refined with an occupancy of 0.5. Another disorder occurs for the solvent methanol with a 1:1 ratio.

The structure of [IrCl2(C58H51N3P4)]Cl·5.5CH3CN or [IrCl2(NHCHPh)(((dppm)C(N2dppm))-κ 3P,C,P)]Cl·5.5CH3CN [3, dppm = bis-(di-phenyl-phos-phino)methane; systematic name: di-chlorido(1,1,3,3,7,7,9,9-octa-phenyl-4,5-di-aza-1,3λ5,7λ4,9-tetra-phosphanona-3,5-dien-6-yl-κ2 P 1,P 9)-(phenyl-methanimine-κN)iridium(III) chloride aceto-nitrile hemihendeca-solvate], resulting from an oxygen-mediated cleavage of a triazeneyl-idene-phospho-rane ligand producing a diazo-methyl-ene-phospho-rane and a nitrene moiety, which in turn rearrange via a Staudinger reaction and a 1,2-hydride shift to the first title complex, involves a six-coordinate IrIII complex cation coordinated by a facial PCP pincer ligand, a benzaldimine and two chlorido ligands. The pincer system features a five- and a seven-membered ring, with the central divalent carbon of the PCP pincer ligand being connected to a phosphine and a diazo-phospho-rane. The chlorido ligands are positioned trans to the central carbon atom and to the phospho-rus donor of the seven-membered ring of the pincer system, respectively. A chloride ion serves as counter-ion for the monocationic complex. The structure of [IrI(C26H22N2P2)(C26H22P2)(C6H7N)]I(I3)·0.5I2·CH3OH·0.5CH2Cl2 or [IrI(NHCHPh)((dppm)C(N2)-κ 2P,C)(dppm-κ 2P,P')]I(I3)·0.5I2·CH3OH·0.5CH2Cl2 {4, systematic name: (4-diazo-1,1,3,3,-tetra-phenyl-1,3λ4-diphosphabutan-4-yl-κP 1)iodido[methyl-enebis(di-phenyl-phosphine)-κ2 P,P'](phenyl-methanimine-κN)iridium(III) iodide-triiodide-di-chloro-methane-iodine-methanol (2/2/1/1/2)}, accessed via treatment of the triazeneyl-idene-phospho-rane complex [Ir((BnN3)C(dppm)-κ 3P,C,N)(dppm-κ 2P,P')]Cl with hydro-iodic acid, consists of a dicationic six-coordinate IrIII complex, coordinated by a bidentate diazo-methyl-ene-phospho-rane, a benzaldimine, a chelating dppm moiety and an iodido ligand. The phospho-rus atoms of the chelating dppm are trans to the central carbon atom of the diazo-methyl-ene-phospho-rane and the iodide ligand, respectively. Both an iodide and a triiodide moiety function as counter-ions. The aceto-nitrile solvent mol-ecules in 3 are severely disordered in position and occupation. In 4, the I3 - anion is positionally disordered (ratio roughly 1:1), as is the I- anion with a ratio of 9:1. The di-chloro-methane solvent mol-ecule lies near a twofold rotation axis (disorder) and was refined with an occupancy of 0.5. Another disorder occurs for the solvent methanol with a 1:1 ratio.

Compound [Ir(C 8 H 12 )(C 51 H 45 P 4 )]Cl 2 or [Ir(cod)(CH(dppm) 2 -κ 3 P , C , P )]Cl 2 ( 1a ), was obtained from [IrCl(cod)] 2 and the carbodiphosphorane (CDP) salt [CH(dppm) 2 ]Cl [where cod = cycloocta-1,5-diene and dppm = bis(diphenylphosphino)methane]. Treatment of 1a with thallium(I) trifluoromethanesulfonate [Tl(OTf)] and subsequent crystallization gave complex [Ir(C 8 H 12 )(C 51 H 45 P 4 )](OTf) 2 ·CH 3 CO 2 C 2 H 5 ·CH 2 Cl 2 or [Ir(cod)(CH(dppm) 2 -κ 3 P , C , P )](OTf) 2 ·CH 3 CO 2 C 2 H 5 ·CH 2 Cl 2 ( 1b ) [systematic name: (cycloocta-1,5-diene)(1,1,3,3,5,5,7,7-octaphenyl-1,7-diphospha-3,5-diphosphoniaheptan-4-yl)iridium(I) bis(trifluoromethanesulfonate)–ethyl acetate–dichloromethane (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 1b represents the first example of a non- meridional coordination of the PCP pincer ligand [CH(dppm) 2 ] + with a P—Ir—P angle of 98.08 (2)°. Compound 2 , [IrCl 2 H(C 51 H 44 P 4 )]·(CH 3 ) 2 CO or [IrCl 2 H(C(dppm) 2 -κ 3 P , C , P )]·(CH 3 ) 2 CO [systematic name: dichloridohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,5λ 5 ,7-triphospha-3-phosphoniahept-4-en-4-yl)iridium(III) acetone monosolvate], crystallizes as an acetone monosolvate. It is a six-coordinate Ir III coordination compound. Here, the PCP pincer ligand is coordinated in a meridional manner; one chlorido ligand is positioned trans to the carbon donor, the remaining two coordination sites being occupied by the second chlorido and a hydrido ligand trans to each other. Complex 3 , [IrCl 2 H(C 51 H 45 P 4 )]Cl·5H 2 O or [IrCl 2 H(CH(dppm) 2 -κ 3 P , C , P )]Cl·5H 2 O [systematic name: dichloridohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,7-diphospha-3,5-diphosphoniaheptan-4-yl)iridium(III) chloride pentahydrate], represents the conjugate CH acid of 2 . The ligand [CH(dppm) 2 ] + is coordinated in a meridional manner. In the cationic six-coordinate Ir III complex 4 , [IrClH(CO)(C 51 H 44 P 4 )]Cl·2CH 3 OH·H 2 O or [IrClH(CO)(C(dppm) 2 -κ 3 P , C , P )]Cl·2CH 3 OH·H 2 O [systematic name: carbonylchloridohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,5λ 5 ,7-triphospha-3-phosphoniahept-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 meridional PCP ligand; the H and CO ligands are positioned axially to this plane and trans to each other.

The common feature of the four iridium(III) salt complexes, (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ 4 P , C , C ′, P ′)chloridohydridoiridium(III) chloride methylene chloride 2.75-solvate ( 4 ), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ 4 P , C , C ′, P ′)chlorido(ethoxyoxoethanido)iridium(III) chloride–methanol–water (1/1/0.5) ( 5 ), (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ 4 P , C , C ′, P ′)dichloridoiridium(III) chloride–methanol–water (1/1/2) ( 6 ) and (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methane-κ 4 P , C , C ′, P ′)carbonyl(ethoxyoxoethanide)iridium(III) dichloride–methylene chloride–water (1/2/1.5) (7) or in terms of their formulae [Ir(C 55 H 50 O 2 P 4 )ClH]Cl·2.75CH 2 Cl 2 ( 4 ), [Ir(C 4 H 7 O 2 )(C 55 H 50 O 2 P 4 )Cl]Cl·CH 3 OH·0.5H 2 O ( 5 ), [Ir(C 55 H 50 O 2 P 4 )Cl 2 ]Cl·CH 3 OH·2H 2 O ( 6 ) and [Ir(C 4 H 7 O 2 )(C 55 H 50 O 2 P 4 )(CO)]Cl 2 ·2CH 2 Cl 2 ·1.5H 2 O ( 7 ) is a central Ir III atom coordinated in a distorted octahedral fashion by a PCCP ligand system and two additional residues, such as chlorides, a hydride, a carbonyl or an alkyl unit. Thereby, the PCP pincer ligand system and the residue trans to the carbodiphosphorane (CDP) C atom surround the iridium(III) transition metal in the equatorial plane under the formation of two five-membered dissimilar chelate rings [C—C CDP —P ( 4 , 5 , 6 and 7 ) for the first ring: 120.2 (3), 121.9 (5), 111.2 (3) and 121.7 (2) °; for the second ring: 112.1 (3), 113.5 (5), 120.5 (3) and 108.3 (2)°]. A cyclopropane-like heterocycle is positioned approximately orthogonal (84.21–88.85°) to the equatorial plane, including an alkylidene bridge connecting the Ir III atom and the coordinating CDP atom of the PCP subunit. In general, the neutral PCCP ligand system coordinates the metal in a tetradentate way via three Lewis acid/base bonds and by an alkylidene unit presenting strengthened interactions. In all the crystal structures, (disordered) solvent molecules are present in the voids of the packed molecules that interact with the positively charged complex and its chloride counter-ion(s) through weak hydrogen bonding.

After the successful creation of the newly designed PCP carbodiphosphorane (CDP) ligand [Reitsamer et al. (2012). Dalton Trans. 41, 3503–3514; Stallinger et al. (2007). Chem. Commun. pp. 510–512], the treatment of this PCP pincer system with the transition metal iridium and further the analysis of the structures by single-crystal diffraction and by NMR spectroscopy were of major interest. Two different iridium complexes, namely (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}methane-κ3P,C,P′)carbonylchloridohydridoiridium(III) chloride dichloromethane trisolvate, [IrIII(CO){C(dppm)2-κ3P,C,P′}ClH]Cl·3CH2Cl2 (1) and the closely related (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}methanide(1+)-κ3P,C,P′)carbonylchloridohydridoiridium(III) dichloride–hydrochloric acid–water (1/2/5.5), [IrIII(CO){CH(dppm)2-κ3P,C,P′)ClH]Cl}2 (2), have been designed and both complexes show a slightly distorted octahedral coordinated IrIII centre. The PCP pincer ligand system is arranged in a meridional manner, the CO ligand is located trans to the central PCP carbon and a hydride and chloride are located perpendicular above and below the P2C2 plane. With an Ir—CCDP distance of 2.157 (5) Å, an Ir—CO distance of 1.891 (6) Å and a quite short C—O distance of 1.117 (7) Å, complex 1 presents a strong carbonyl bond. Complex 2, the corresponding CH acid of 1, shows an additionally attached proton at the carbodiphosphorane carbon atom located antiperiplanar to the hydride of the metal centre. In comparison with complex 1, the Ir—CCDP distance of 2.207 (3) Å is lengthened and the Ir—C—O values indicate a weaker trans influence of the central carbodiphosphorane carbon atom.

The structure of [Ir{(4-Cl-C6H4N3)C(dppm)-κ3 P,C,N}(dppm-κ2 P,P′)]Cl·1.5CH2Cl2·0.5C7H8 (C57H48Cl2IrN3P4·1.5CH2Cl2·0.5C7H8) (2), dppm = bis(diphenylphosphino)methane {systematic name: [7-(4-chlorophenyl)-1,1,3,3-tetraphenyl-5,6,7-triaza-κN 7-1,3λ4-diphospha-κP 1-hepta-4,6-dien-4-yl][methylenebis(diphenylphosphine)-κ2 P,P′]iridium(I) chloride–dichloromethane–toluene (2/3/1)}, resulting from the reaction of [IrClH{C(dppm)2-κ3 P,C,P)(MeCN)]Cl (1a) with 1-azido-4-chlorobenzene, shows a monocationic five-coordinate IrI complex with a distorted trigonal–bipyramidal geometry. In 2, the iridium centre is coordinated by the neutral triazeneylidenephosphorane (4-Cl-C6H4N3)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)]·CH3CN, (C52H45ClIrNP4·CH3CN) (1b) [systematic name: chloridocyanidohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,3λ5,5λ4,7-tetraphospha-κ2 P 1,P 7-hept-3-en-4-yl)iridium(III) acetonitrile monosolvate], prepared from 1a and KCN, reveals an octahedral IrIII central atom with a meridional PCP pincer carbodiphosphorane (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-C6H4N3)CH(CH(P(Ph)2)2)-κ3 P,C,N)(dppm-κ2 P,P′)]·2CH3OH, (C58H48ClIrN4P4·2CH3OH) (3) (systematic name: {4-[3-(4-chlorophenyl)triazenido-κN 3]-1,1,3,3-tetraphenyl-1,3λ5-diphospha-κP 1-but-2-en-4-yl}cyanido[methylenebis(diphenylphosphine)-κ2 P,P′]iridium(III) methanol disolvate), formed via prolonged reaction of 1-azido-4-chlorobenzene with 1b, features a six-coordinate IrIII central atom. The iridium centre is coordinated by the dianionic facial PCN pincer ligand [(4-Cl-C6H4N3)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 CH2Cl2 and C7H8 solvent molecules show occupational disorder, with the toluene molecule exhibiting additional 1:1 positional disorder with some nearly overlying carbon atoms.

The reaction of [Ir III {C(dppm) 2 -κ 3 P , C , P ′}ClH(NH 3 C 2 )]Cl with ethyl diazoacetate, a well known C=C coupling reagent, leads to the formation of a C=C unit, accompanied by N 2 abstraction, reorganization of a dppm subunit and, considered as a whole, to the transformation of the PCP pincer carbodiphosphorane system to a phosphorus ylide ligand. After removal of the halogenides, the iridium center is stabilized by the carbonyl O atom through the formation of a five-membered chelate ring. A PCO pincer ligand system is thereby generated, which coordinates the iridium(III) atom threefold in a facial manner. The phosphorus electron-donor atoms and the ylide carbon atom of the resulting [Ir III {C(C 4 H 6 O 2 )(dppm)-κ 3 P , C , O }(dppm)H](CF 3 O 3 S) 2 complex, also termed as [bis(diphenylphosphanyl)methane]({[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methanylidene-κ 3 P , C , O )hydridoiridium(III) bis(trifluoromethanesulfonate), are in plane and the hydrido ligand and the carbonyl O atom are located trans to each other, perpendicular to the meridional plane. The addition of carbon monoxide causes a replacement of the carbonyl O atom of the acetate subunit by a carbonyl ligand, thereby creating [bis(diphenylphosphanyl)methane]carbonyl({[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methanylidene-κ 2 P , C }hydridoiridium(III) bis(trifluoromethanesulfonate)–dichloromethane–ethyl acetate (6/2/3) or, more simply, [Ir III {C(C 4 H 6 O 2 )(dppm)-κ 2 P , C }(CO)(dppm)H](CF 3 O 3 S) 2 ·0.33CH 2 Cl 2 ·0.5C 4 H 8 O 2 . One trifluoromethanesulfonate counter-ion of 3 shows positional disorder in a 2:1 ratio. Complex 4 shows pseudo-merohedral twinning (matrix: \overline{1} 0 0 0 \overline{1} 0 1 0 1). The dichloromethane solvent is disordered over two orientations with occupation factors of 0.5 and 0.166.

The reaction of [IrIII{C(dppm)2-κ3P,C,P′}ClH(NH3C2)]Cl with ethyl diazo­acetate, a well known C=C coupling reagent, leads to the formation of a C=C unit, accompanied by N2 abstraction, reorganization of a dppm subunit and, considered as a whole, to the transformation of the PCP pincer carbodi­phospho­rane system to a phospho­rus ylide ligand. After removal of the halogenides, the iridium center is stabilized by the carbonyl O atom through the formation of a five-membered chelate ring. A PCO pincer ligand system is thereby generated, which coordinates the iridium(III) atom threefold in a facial manner. The phospho­rus electron-donor atoms and the ylide carbon atom of the resulting [IrIII{C(C4H6O2)(dppm)-κ3P,C,O}(dppm)H](CF3O3S)2 complex, also termed as [bis­(di­phenyl­phosphan­yl)methane]({[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methanyl­idene-κ3P,C,O)hydridoiridium(III) bis­(tri­fluoro­methane­sulfonate), are in plane and the hydrido ligand and the carbonyl O atom are located trans to each other, perpendicular to the meridional plane. The addition of carbon monoxide causes a replacement of the carbonyl O atom of the acetate subunit by a carbonyl ligand, thereby creating [bis­(di­phenyl­phosphan­yl)methane]­carbon­yl({[(di­phenyl­phosphan­yl)meth­yl]di­phenyl­phosphanyl­idene}(eth­oxy­oxoethanyl­idene)methanyl­idene-κ2P,C}hydridoiridium(III) bis­(tri­fluoro­methane­sulfonate)–di­chloro­methane–ethyl acetate (6/2/3) or, more simply, [IrIII{C(C4H6O2)(dppm)-κ2P,C}(CO)(dppm)H](CF3O3S)2·0.33CH2Cl2·0.5C4H8O2. One tri­fluoro­meth­ane­sulfonate counter-ion of 3 shows positional disorder in a 2:1 ratio. Complex 4 shows pseudo-merohedral twinning (matrix: Unlabelled Image 0 0 0 Unlabelled Image 0 1 0 1). The di­chloro­methane solvent is disordered over two orientations with occupation factors of 0.5 and 0.166.

Gold(III) complexes of the PCP pincer carbodiphosphorane (CDP) ligand C(dppm)2 and gold(I) complexes of the conjugate CH acid [CH(dppm)2]+ were synthesized and characterized by single crystal diffraction and by NMR spectroscopy. The gold(I) complex [AuCl(CH(dppm)2)-κ2P,P′]Cl (1) exhibits an approximate trigonal planar AuClP2 core, whereas the gold center in the [Au(CH(dppm)2)-κ2P,P′)](TfO)2 complex (2) is only two-coordinated (P(1)-Au(1)-P(4) around 167.3°). Both complexes show no significant interaction between the gold(I) and the CDP carbon and consequently, an eight membered chelate ring is observed. [AuI(C(dppm)2)-κ3P,C,P′)](TfO)2 (3) and [AuCl(C(dppm)2)-κ3P,C,P′)](NO3)2 (4) were obtained via oxidation of complex 1 or 2 with iodine or nitric acid, respectively. The gold(III) center is stabilized in a square planar coordination geometry by two dppm units, the divalent carbon(0) atom of the C(dppm)2 ligand system, and a halide ion.

In a novel template synthesis of carbodiphosphoranes (CDPs), the phosphine functionalized CDP ligand C(dppm)(2) (dppm = Ph(2)PCH(2)PPh(2)) is formed in the coordination sphere of group 10 metals from CS(2) and 4 equivalents of dppm. The products are the PCP pincer complexes [M(Cl)(C(dppm)(2)-κ3P,C,P)]Cl (M = Ni, Pd, Pt) and 2 equivalents of dppmS. The compound C(dppm)(2), which is composed of a divalent carbon atom and two dppm subunits, represents a new PCP-type pincer ligand with the formally neutral carbon Lewis base of the CDP functionality as the central carbon. Treatment of [M(Cl)(C(dppm)(2)-κ3P,C,P)]Cl (M = Pd, Pt) with hydrochloric acid results in protonation at the CDP carbon atom and the formation of the PCP pincer complexes [M(Cl)(CH(dppm)(2)-κ3P,C,P)]Cl(2) (M = Pd, Pt). The PCP pincer ligand [CH(dppm)(2)](+) involves a formally cationic central carbon donor. The reaction of [Ni(Cl)(C(dppm)(2)-κ3P,C,P)]Cl with HCl leads to the extrusion of NiCl(2) and formation of the diprotonated CDP compound [CH(2)(dppm)(2)]Cl(2), from which the monoprotonated conjugate base [CH(dppm)(2)]Cl is obtained upon addition of bases, such as NH(3). The crystal structures of [M(Cl)(C(dppm)(2)-κ3P,C,P)]Cl (M = Ni, Pd, Pt), [Ni(Cl)(C(dppm)(2)-κ3P,C,P)](2)[NiCl(4)], [M(Cl)(CH(dppm)(2)-κ3P,C,P)]Cl(2) (M = Pd, Pt) as well as [CH(2)(dppm)(2)]Cl(2) and [CH(dppm)(2)]Cl are presented. A comparison of the solid state structures reveals interesting features, e.g. infinite supramolecular networks mediated by C-H···Cl hydrogen bond interactions and an unexpected loss of molecular symmetry upon protonation in the complexes [M(CH(dppm)(2)-κ3P,C,P)(Cl)]Cl(2) (M = Pd, Pt) as a result of the flexible ligand backbone. Additionally the new compounds were characterized comprehensively in solution by multinuclear (31)P, (13)C and (1)H NMR spectroscopy: Several spectroscopic parameters show a striking variability in particular regarding the carbodiphosphorane functionality. Furthermore the compound [Ni(Cl)(C(dppm)(2)-κ3P,C,P)]Cl was examined by cyclic voltammetry (CV) and could be shown to display quasi-reversible oxidative as well as reductive behaviour.

An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.

The reaction of the protonated PCP pincer carbodiphosphorane (CDP) complex [PdCl(CH(dppm)(2))]Cl-2 (1) with [PdCl2(MeCN)(2)] results in the opening of one ring of the pincer structure and affords the betaine [Pd2CH(CH(dppm)(2))] (2). The [CH(dppm)(2)](+) ligand forms a five-membered chelate ring with the Pd(1)Cl-2 moiety via the protonated CDP carbon (positively charged) and one phosphine functionality and bridges to the anionic Pd(2)Cl-3 fragment via the second phosphine phosphorus. The complex is chiral due to a stereocenter at the protonated CDP carbon atom. Treatment of 2 with water effects deprotonation of the CDP carbon, C H activation at one methylene group, and the coordination of the second Pd to the CDP carbon. The resulting tricyclic complex [Pd2Cl3(C(dppm)(Ph2CHPh2))] (3) is the first compound with two Pd centers coordinated to a CDP carbon. Compound 3 forms a single-stranded helicate structure and exhibits two interdependent carbon stereocenters, resulting in only two possible enantiomers. The complexes 2 center dot 2CH(2)Cl(2) and 3 center dot 3CH(2)Cl(2) crystallize in the chiral space group P2(1), whereby a spontaneous resolution of the enantiomers occurs in both cases.

HistopathologyVolume 54, Issue 6 p. 775-777 Improved ultrastructural resolution by a new re-embedding procedure for formaldehyde-fixed paraffin-embedded tissues Hans-Jörg Steiner, Hans-Jörg Steiner Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorPaul Peringer, Paul Peringer Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, InnsbruckSearch for more papers by this authorPatrizia Moser, Patrizia Moser Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorThomas Schmid, Thomas Schmid Department of Surgery, Medical University of Innsbruck, Innsbruck, AustriaSearch for more papers by this authorMichael A Kern, Michael A Kern Department of Pathology, University Hospital Heidelberg, Heidelberg, GermanySearch for more papers by this authorChristina M Steger, Christina M Steger Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorGregor Mikuz, Gregor Mikuz Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorRalf J Rieker, Ralf J Rieker Department of Pathology, Medical University of Innsbruck, Innsbruck Department of Pathology, University Hospital Heidelberg, Heidelberg, GermanySearch for more papers by this author Hans-Jörg Steiner, Hans-Jörg Steiner Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorPaul Peringer, Paul Peringer Department of General, Inorganic and Theoretical Chemistry, University of Innsbruck, InnsbruckSearch for more papers by this authorPatrizia Moser, Patrizia Moser Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorThomas Schmid, Thomas Schmid Department of Surgery, Medical University of Innsbruck, Innsbruck, AustriaSearch for more papers by this authorMichael A Kern, Michael A Kern Department of Pathology, University Hospital Heidelberg, Heidelberg, GermanySearch for more papers by this authorChristina M Steger, Christina M Steger Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorGregor Mikuz, Gregor Mikuz Department of Pathology, Medical University of Innsbruck, InnsbruckSearch for more papers by this authorRalf J Rieker, Ralf J Rieker Department of Pathology, Medical University of Innsbruck, Innsbruck Department of Pathology, University Hospital Heidelberg, Heidelberg, GermanySearch for more papers by this author First published: 24 April 2009 https://doi.org/10.1111/j.1365-2559.2009.03291.xRead the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat References 1 Soyer H, Peter MD, Metze D, Kerl H. Granular cell dermatofibroma. Am. J. Dermatopathol. 1997; 19; 168–173. 10.1097/00000372-199704000-00011 CASPubMedWeb of Science®Google Scholar 2 Nasr SH, Markowitz GS, Valeri AM, Yu Z, Chen L, D′Agati VD. Thin basement membrane nephropathy cannot be diagnosed reliably in deparaffinised, formalin-fixed tissue. Nephrol. Dial. Transplant. 2007; 22; 1228–1232. 10.1093/ndt/gfl838 PubMedWeb of Science®Google Scholar 3 Wang NS, Minassian H. The formaldehyde fixed and paraffin-embedded tissues for diagnostic transmission electron microscopy: a retrospective and prospective study. Hum. Pathol. 1987; 18; 715–727. 10.1016/S0046-8177(87)80243-5 CASPubMedWeb of Science®Google Scholar Volume54, Issue6May 2009Pages 775-777 ReferencesRelatedInformation

The first heterodimetallic PCP pincer complex, [PdAu(Cl)(2)(C(dppm)(2))]Cl, was prepared from [PdCl(C(dppm)(2))]Cl and [AuCl(tht)]. Both metals are attached to the carbon atom of the carbodiphosphorane (CDP) functionality and are connected via a very short d(8)-d(10) pseudo-closed-Shell interaction (Pd-Au = 2.8900(3) angstrom) which significantly modifies the ligand backbone conformation.

Intramolecular exchange by alkene rotation observed for the first time in a dinuclear d(9)-Pt(l) olefin complex was evidenced for [Pt-2(mu-dppm)(mu-PPh2)(eta(2)-bicyclo[2.2.1]hept-2-ene)(2)](O3SCF3) (1) (dppm = bis(diphenylphosphino)methane). The dynamic behavior leads to the occurrence of two diastereomers in solution with relative syn and anti orientation of the two in-plane coordinated bicyclo[2.2.1]hept-2-ene ligands. The low activation energy Delta G(rot)double dagger of 43 kJ/mol found for this exchange process was attributed (a) to a favorable geometry due to the ample P-Pt-P angle of the phosphorus ligands in mutual trans position promoting flexibility and reducing steric hindrance in the intermediate or transition state with upright alkene orientation and (b) to the positive charge of the complex cation, which reduces the ability of platinum for metal-to-ligand pi-back-donation compared to neutral or anionic complexes. Intramolecular alkene rotation was also observed for the Lewis acid adducts at the Pt-Pt bond of 1 with Ag+, [Pt-2(mu-Ag)(mu-dppm)(mu-PPh2)(eta(2)-bicyclo[2.2.1]hept-2-ene)(2)](O3SCF3)(2) (2), and H+, [Pt-2(mu-H)(mu-dppm)(mu-PPh2)(eta(2)- bicyclo[2.2.1]hept-2-ene)(2)](O3SCF3)(2) (3), respectively. The solid state structure of 2 was determined by single-crystal X-ray diffraction and reveals that the core geometry of the [Pt-2(mu-dppm)(mu-PPh2)(eta(2)- bicyclo[2.2.1]hept-2-ene)21 framework remains substantially unchanged compared with the parent compound I upon Ag+ coordination at the Pt-Pt bond. No A-frame structure is formed as usually observed in di-Pt(l) complexes. Complex 3, containing a bridging hydride ligand across both platinum centers, displays-besides alkene rotation-an additional, unique intramolecular fluxionality by tunneling of hydrogen through the Pt-Pt bond.

The mercury(I) complexes [Hg-2(phen)(4)](OTf)(2) and [Hg-2(phen)(2)](OTf)(2) (phen = 1,10-phenanthroline) were prepared and characterized by single crystal X-ray diffraction. The structure of [Hg-2(phen)(4)](OTf)(2) exhibits an Hg2N8 kernel, which involves the highest number of N-donor atoms coordinated to Hg-2(2+) reported so far. The Hg-N distances of [Hg-2(phen)(4)](OTf)(2) cover a range of 238.5-266.6 pm. Supramolecular structures were built in both complexes via pi-pi stacking of the phenanthroline ligands. (c) 2007 Elsevier B.V. All rights reserved.