scholarly journals Crystal structures of the [IrIII{C(C4H6O2)(dppm)-κ3 P,C,O}(dppm)H](CF3O3S)2 and [IrIII{C(C4H6O2)(dppm)-κ2 P,C}(CO)(dppm)H](CF3O3S)2 phosphorus ylide complexes, generated by a Wittig-type carbon–carbon coupling reaction of a carbodiphosphorane PCP ligand system

2018 ◽  
Vol 74 (11) ◽  
pp. 1643-1647 ◽  
Author(s):  
Inge Schlapp-Hackl ◽  
Bettina Pauer ◽  
Christoph Falschlunger ◽  
Walter Schuh ◽  
Holger Kopacka ◽  
...  
Keyword(s):  
Chelate Ring ◽  
Coupling Reaction ◽  
Carbonyl Ligand ◽  
Pincer Ligand ◽  
Positional Disorder ◽  
Phosphorus Ylide ◽  
Ligand System ◽  
Coupling Reagent ◽  
Pcp Pincer ◽  
Ylide Complexes

The reaction of [IrIII{C(dppm)2-κ3 P,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)-κ3 P,C,O}(dppm)H](CF3O3S)2 complex, also termed as [bis(diphenylphosphanyl)methane]({[(diphenylphosphanyl)methyl]diphenylphosphanylidene}(ethoxyoxoethanylidene)methanylidene-κ3 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-κ2 P,C}hydridoiridium(III) bis(trifluoromethanesulfonate)–dichloromethane–ethyl acetate (6/2/3) or, more simply, [IrIII{C(C4H6O2)(dppm)-κ2 P,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: \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.

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.

Iron pyrrole-based PNP pincer ligand complexes as catalyst precursors

2017 ◽  
Vol 73 (7) ◽  
pp. 569-574 ◽  
Author(s):  
Amanda M. Holland ◽  
Allen G. Oliver ◽  
Vlad M. Iluc
Keyword(s):  
Iron Catalysts ◽  
Distorted Octahedral Geometry ◽  
Carbonyl Ligand ◽  
Pyridine Ligand ◽  
Pincer Ligand ◽  
Tridentate Ligands ◽  
Apical Position ◽  
Positional Disorder ◽  
Carbonyl Ligands ◽  
Distorted Octahedral

The structure of a pincer ligand consists of a backbone and two `arms' which typically contain a P or N atom. They are tridentate ligands that coordinate to a metal center in a meridional configuration. A series of three iron complexes containing the pyrrole-based PNP pincer ligand 2,5-bis[(diisopropylphosphanyl)methyl]pyrrolide (PNpyrP) has been synthesized. These complexes are possible precursors to new iron catalysts. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}carbonylchlorido(trimethylphosphane-κP)iron(II), [Fe(C18H34NP2)Cl(C3H9P)(CO)] or [Fe(PNpyrP)Cl(PMe3)(CO)], (I), has a slightly distorted octahedral geometry, with the Cl and CO ligands occupying the apical positions. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}chlorido(pyridine-κN)iron(II), [Fe(C18H34NP2)Cl(C5H5N)] or [Fe(PNpyrP)Cl(py)] (py is pyridine), (II), is a five-coordinate square-pyramidal complex, with the pyridine ligand in the apical position. {2,5-Bis[(diisopropylphosphanyl)methyl]pyrrolido-κ3 P,N,P′}dicarbonylchloridoiron(II), [Fe(C18H34NP2)Cl(CO)2] or [Fe(PNpyrP)Cl(CO)2], (III), is structurally similar to (I), but with the PMe3 ligand replaced by a second carbonyl ligand from the reaction of (II) with CO. The two carbonyl ligands are in a cis configuration, and there is positional disorder of the chloride and trans carbonyl ligands.

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 CHELATE PHOSPHORUS YLIDE COMPLEXES OF PALLADIUM AND PLATINUM

1975 ◽  
Vol 4 (12) ◽  
pp. 1259-1260 ◽  
Author(s):  
Yoshinao Oosawa ◽  
Taro Saito ◽  
Yukiyoshi Sasaki
Keyword(s):  
Phosphorus Ylide ◽  
Ylide Complexes

Lewis Acid Catalysis with Cationic Dinuclear Gold(II,II) and Gold(III,III) Phosphorus Ylide Complexes

2016 ◽  
Vol 35 (17) ◽  
pp. 2830-2835 ◽  
Author(s):  
Benjamin R. Reiner ◽  
Mark W. Bezpalko ◽  
Bruce M. Foxman ◽  
Casey R. Wade
Keyword(s):  
Lewis Acid ◽  
Acid Catalysis ◽  
Lewis Acid Catalysis ◽  
Phosphorus Ylide ◽  
Ylide Complexes

A hexanuclear iridium complex with a novel binding mode of a PCP–pincer ligand

2004 ◽  
Vol 357 (10) ◽  
pp. 3014-3018 ◽  
Author(s):  
Xiawei Zhang ◽  
Thomas J Emge ◽  
Alan S Goldman
Keyword(s):  
Binding Mode ◽  
Iridium Complex ◽  
Pincer Ligand ◽  
Pcp Pincer

Novel vanadium and titanium phosphorus ylide complexes

1996 ◽  
pp. 779 ◽  
Author(s):  
Pietro Berno ◽  
Sandro Gambarotta ◽  
Sirpa Kotila ◽  
Gerhard Erker
Keyword(s):  
Phosphorus Ylide ◽  
Ylide Complexes

scholarly journals Asymmetric Primaquine and Halogenaniline Fumardiamides as Novel Biologically Active Michael Acceptors

Molecules ◽  
2018 ◽  
Vol 23 (7) ◽  
pp. 1724 ◽  
Author(s):  
Zrinka Rajić ◽  
Maja Beus ◽  
Hana Michnová ◽  
Josipa Vlainić ◽  
Leentje Persoons ◽  
...  
Keyword(s):  
Sindbis Virus ◽  
Lymphoblastic Leukemia ◽  
Human Tumor ◽  
Coupling Reaction ◽  
Biologically Active ◽  
Coxsackie Virus ◽  
Significant Activity ◽  
Coupling Reagent ◽  
Michael Acceptors ◽  
Punta Toro Virus

Novel primaquine (PQ) and halogenaniline asymmetric fumardiamides 4a–f, potential Michael acceptors, and their reduced analogues succindiamides 5a–f were prepared by simple three-step reactions: coupling reaction between PQ and mono-ethyl fumarate (1a) or mono-methyl succinate (1b), hydrolysis of PQ-dicarboxylic acid mono-ester conjugates 2a,b to corresponding acids 3a,b, and a coupling reaction with halogenanilines. 1-[bis(Dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxide hexafluorophosphate (HATU) was used as a coupling reagent along with Hünig′s base. Compounds 4 and 5 were evaluated against a panel of bacteria, several Mycobacterium strains, fungi, a set of viruses, and nine different human tumor cell lines. p-Chlorofumardiamide 4d showed significant activity against Staphylococcus aureus,Streptococcus pneumoniae and Acinetobacter baumannii, but also against Candida albicans (minimum inhibitory concentration (MIC) 6.1–12.5 µg/mL). Together with p-fluoro and p-CF3 fumardiamides 4b,f, compound 4d showed activity against Mycobacterium marinum and 4b,f against M. tuberculosis. In biofilm eradication assay, most of the bacteria, particularly S. aureus, showed susceptibility to fumardiamides. m-CF3 and m-chloroaniline fumardiamides 4e and 4c showed significant antiviral activity against reovirus-1, sindbis virus and Punta Toro virus (EC50 = 3.1–5.5 µM), while 4e was active against coxsackie virus B4 (EC50 = 3.1 µM). m-Fluoro derivative 4a exerted significant cytostatic activity (IC50 = 5.7–31.2 μM). Acute lymphoblastic leukemia cells were highly susceptible towards m-substituted derivatives 4a,c,e (IC50 = 6.7–8.9 μM). Biological evaluations revealed that fumardiamides 4 were more active than succindiamides 5 indicating importance of Michael conjugated system.

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