Prototropic rearrangements in cycloheptatrienyl PCP pincer iridium complexes

2008 ◽  
pp. 527-532 ◽  
Author(s):  
Angelika M. Winter ◽  
Klaus Eichele ◽  
Hans-Georg Mack ◽  
William C. Kaska ◽  
Hermann A. Mayer
Keyword(s):  
Iridium Complexes ◽  
Pcp Pincer

Benzo annulated cycloheptatriene PCP pincer iridium complexes

2014 ◽  
Vol 43 (32) ◽  
pp. 12187-12199 ◽  
Author(s):  
Wolfgang Leis ◽  
Sophie Wernitz ◽  
Benedikt Reichart ◽  
David Ruckerbauer ◽  
Johannes Wolfram Wielandt ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Iridium Complexes ◽  
Pincer Complex ◽  
Pcp Pincer

Chemical conversions of a cycloheptatriene iridium pincer complex were studied by NMR and MS techniques as well as DFT calculations.

scholarly journals Crystal structure of an iridium(III) complex of the [C(dppm)2] PCP pincer ligand system and its conjugate CH acid form

2018 ◽  
Vol 74 (5) ◽  
pp. 620-624 ◽  
Author(s):  
Christian Reitsamer ◽  
Inge Schlapp-Hackl ◽  
Gabriel Partl ◽  
Walter Schuh ◽  
Holger Kopacka ◽  
...  
Keyword(s):  
Carbon Atom ◽  
Iridium Complexes ◽  
Pincer Ligand ◽  
Single Crystal Diffraction ◽  
Dalton Trans ◽  
Ligand System ◽  
Distorted Octahedral ◽  
Major Interest ◽  
Carbonyl Bond ◽  
Pcp Pincer

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-κ3 P,C,P′)carbonylchloridohydridoiridium(III) chloride dichloromethane trisolvate, [IrIII(CO){C(dppm)2-κ3 P,C,P′}ClH]Cl·3CH2Cl2 (1) and the closely related (bis{[(diphenylphosphanyl)methyl]diphenylphosphanylidene}methanide(1+)-κ3 P,C,P′)carbonylchloridohydridoiridium(III) dichloride–hydrochloric acid–water (1/2/5.5), [IrIII(CO){CH(dppm)2-κ3 P,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.

scholarly journals Crystal structures of four new iridium complexes, each containing a highly flexible carbodiphosphorane PCP pincer ligand

2018 ◽  
Vol 74 (6) ◽  
pp. 846-852 ◽  
Author(s):  
Gabriel Julian Partl ◽  
Felix Nussbaumer ◽  
Inge Schlapp-Hackl ◽  
Walter Schuh ◽  
Holger Kopacka ◽  
...  
Keyword(s):  
Double Bond ◽  
Ethyl Acetate ◽  
Crystal Structures ◽  
Complex Cation ◽  
Iridium Complexes ◽  
Pincer Ligand ◽  
Coordination Sites ◽  
Trigonal Bipyramidal ◽  
Pcp Pincer ◽  
Chloride Pentahydrate

Compound [Ir(C8H12)(C51H45P4)]Cl2or [Ir(cod)(CH(dppm)2-κ3P,C,P)]Cl2(1a), was obtained from [IrCl(cod)]2and the carbodiphosphorane (CDP) salt [CH(dppm)2]Cl [where cod = cycloocta-1,5-diene and dppm = bis(diphenylphosphino)methane]. Treatment of1awith thallium(I) trifluoromethanesulfonate [Tl(OTf)] and subsequent crystallization gave complex [Ir(C8H12)(C51H45P4)](OTf)2·CH3CO2C2H5·CH2Cl2or [Ir(cod)(CH(dppm)2-κ3P,C,P)](OTf)2·CH3CO2C2H5·CH2Cl2(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. Compound1brepresents the first example of a non-meridionalcoordination of the PCP pincer ligand [CH(dppm)2]+with a P—Ir—P angle of 98.08 (2)°. Compound2, [IrCl2H(C51H44P4)]·(CH3)2CO or [IrCl2H(C(dppm)2-κ3P,C,P)]·(CH3)2CO [systematic name: dichloridohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,5λ5,7-triphospha-3-phosphoniahept-4-en-4-yl)iridium(III) acetone monosolvate], crystallizes as an acetone monosolvate. It is a six-coordinate IrIIIcoordination compound. Here, the PCP pincer ligand is coordinated in ameridionalmanner; one chlorido ligand is positionedtransto the carbon donor, the remaining two coordination sites being occupied by the second chlorido and a hydrido ligandtransto each other. Complex3, [IrCl2H(C51H45P4)]Cl·5H2O or [IrCl2H(CH(dppm)2-κ3P,C,P)]Cl·5H2O [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 of2. The ligand [CH(dppm)2]+is coordinated in ameridionalmanner. In the cationic six-coordinate IrIIIcomplex4, [IrClH(CO)(C51H44P4)]Cl·2CH3OH·H2O or [IrClH(CO)(C(dppm)2-κ3P,C,P)]Cl·2CH3OH·H2O [systematic name: carbonylchloridohydrido(1,1,3,3,5,5,7,7-octaphenyl-1,5λ5,7-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 themeridionalPCP ligand; the H and CO ligands are positioned axially to this plane andtransto each other.

scholarly journals Crystal structures of two PCN pincer iridium complexes and one PCP pincer carbodiphosphorane iridium intermediate: substitution of one phosphine moiety of a carbodiphosphorane by an organic azide

2019 ◽  
Vol 75 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Gabriel Julian Partl ◽  
Felix Nussbaumer ◽  
Walter Schuh ◽  
Holger Kopacka ◽  
Klaus Wurst ◽  
...  
Keyword(s):  
Coordination Compound ◽  
Central Atom ◽  
Iridium Complexes ◽  
Pincer Ligand ◽  
Organic Azide ◽  
Positional Disorder ◽  
Central Carbon ◽  
Chloride Ligand ◽  
Solvent Molecules ◽  
Pcp Pincer

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.

scholarly journals Catalytic Dehydrogenation of Alkanes by PCP–Pincer Iridium Complexes Using Proton and Electron Acceptors

ACS Catalysis ◽  
2021 ◽  
pp. 3009-3016
Author(s):  
Arun Dixith Reddy Shada ◽  
Alexander J. M. Miller ◽  
Thomas J. Emge ◽  
Alan S. Goldman
Keyword(s):  
Electron Acceptors ◽  
Catalytic Dehydrogenation ◽  
Iridium Complexes ◽  
Pcp Pincer

Regioselective Gas-Phase n-Butane Transfer Dehydrogenation via Silica-Supported Pincer-Iridium Complexes

2020 ◽  
Author(s):  
Boris Sheludko ◽  
Cristina Castro ◽  
Chaitanya Khalap ◽  
Thomas Emge ◽  
Alan Goldman ◽  
...  
Keyword(s):  
Gas Phase ◽  
Active Site ◽  
Lower Cost ◽  
Open Systems ◽  
Iridium Complexes ◽  
Terminal Olefin ◽  
Molecular Precursors ◽  
Sterically Demanding ◽  
Olefin Production ◽  
Steam Cracking

<b>Abstract:</b> The production of olefins via on-purpose dehydrogenation of alkanes allows for a more efficient, selective and lower cost alternative to processes such as steam cracking. Silica-supported pincer-iridium complexes of the form [(≡SiO-<sup>R4</sup>POCOP)Ir(CO)] (<sup>R4</sup>POCOP = κ<sup>3</sup>-C<sub>6</sub>H<sub>3</sub>-2,6-(OPR<sub>2</sub>)<sub>2</sub>) are effective for acceptorless alkane dehydrogenation, and have been shown stable up to 300 °C. However, while solution-phase analogues of such species have demonstrated high regioselectivity for terminal olefin production under transfer dehydrogenation conditions at or below 240 °C, in open systems at 300 °C, regioselectivity under acceptorless dehydrogenation conditions is consistently low. In this work, complexes <a>[(≡SiO-<i><sup>t</sup></i><sup>Bu4</sup>POCOP)Ir(CO)] </a>(<b>1</b>) and [(≡SiO-<i><sup>i</sup></i><sup>Pr4</sup>PCP)Ir(CO)] (<b>2</b>) were synthesized via immobilization of molecular precursors. These complexes were used for gas-phase butane transfer dehydrogenation using increasingly sterically demanding olefins, resulting in observed selectivities of up to 77%. The results indicate that the active site is conserved upon immobilization.

Diphosphinoazine Rhodium(I) and Iridium(I) Complexes

2006 ◽  
Vol 71 (2) ◽  
pp. 197-206 ◽  
Author(s):  
Martin Pošta ◽  
Jan Čermák ◽  
Pavel Vojtíšek ◽  
Ivana Císařová
Keyword(s):  
Rhodium Complexes ◽  
Iridium Complexes ◽  
X Ray ◽  
First Time

The first rhodium complexes of diphosphinoazines [{RhCl(1,2-η:5,6-η-CH=CHCH2CH2CH=CHCH2CH2)}2 {μ-R2PCH2C(But)=NN=C(But)CH2PR2] (R = Ph, Cy, Pri) were prepared by cleavage of the bridge in chloro(cycloocta-1,5-diene)rhodium(I) dimer, the analogous iridium(I) complexes were also prepared for the first time. The X-ray structures of isostructural rhodium and iridium complexes with bis(dicyclohexylphosphino)pinacoloneazine were determined. Diphosphinoazine ligands in the complexes remained in (Z,Z) configuration bridging two RhCl(C8H12) units.

scholarly journals Synthesis, characterization, and photoelectric properties of iridium(iii) complexes containing an N hetero-dibenzofuran C^N ligand

RSC Advances ◽  
2021 ◽  
Vol 11 (18) ◽  
pp. 11004-11010
Author(s):  
Zequn Ma ◽  
Chaojun Jing ◽  
Deyu Hang ◽  
Hongtao Fan ◽  
Lumeng Duan ◽  
...  
Keyword(s):  
Electrochemical Properties ◽  
Green Light ◽  
Iridium Complexes ◽  
Thermal Stabilities ◽  
Photoelectric Properties ◽  
High Efficient

Three high-efficient green light iridium complexes were designed and prepared. Thermal stabilities, electrochemical properties, electroluminescence performances and substituents effects are presented and discussed in this study.

Arene ruthenium, rhodium and iridium complexes containing benzamide derivative ligands: Study of interesting bonding modes, antibacterial, antioxidant and DNA binding studies

2021 ◽  
Vol 937 ◽  
pp. 121731
Author(s):  
Lathewdeipor Shadap ◽  
Nipanshu Agarwal ◽  
Vivek Chetry ◽  
Krishna Mohan Poluri ◽  
Werner Kaminsky ◽  
...  
Keyword(s):  
Dna Binding ◽  
Iridium Complexes ◽  
Binding Studies ◽  
Dna Binding Studies
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