Complex RhCl Research Articles

Formation of an η 1-ylidic enamine complex of rhodium(III) during use of triethylamine for a base-promoted reaction

Reaction of triethylamine with mer-RhCl 3(dmso) 3 leads to dehydrogenation of an alkyl group of the amine, and formation of isomers of the ylid complex RhCl 3(dmso) 2(η 1-CH 2CHNEt 2), with accompanying production of equivalent amounts of rhodium(I) species.

Rhodium(I)-mono- und -diazadienkomplexe, synthese, spektroskopische charakterisierung, oxidative additionsreaktionen und einsatz in der homogenen katalyse zur hydrosilylierung

The reaction of [Rh(CO) 2Cl) 2 with di- and monoazadienes gives planar, four-coordinated rhodium(I) complexes Rh(CO)Cl(DAD) (III) and Rh(CO)Cl(MAD) 2 (V), respectively, which catalyse the hydrosilylation of alkenes and alkynes. In a stereoselective cis-addition symmetric internal alkynes give the corresponding silyl alkenes, while the catalytic addition of silane to terminal alkynes leads to the 2-silyl and cis- and trans-1-silyl-alkenes; their ratio depends on the controlling ligand and on the reaction conditions. With a stoichiometric amount of the silane the complexes III react under oxidative addition to give the rhodium(III) complexes Rh(H)(SiR 3)(DAD)Cl (VI), which also catalyse the hydrosilylation.

OLIGOPHOSPHAN-LIGANDEN, XV1SYNTHESE MEHRZÄHNIGER PHOSPHANE DURCH RADIKALISCHE PH-ADDITION AN OLEFINISCHE DOPPELBINDUNGSSYSTEME: STUDIEN ZUR ANWENDUNGSBREITE DER METHODE

Abstract The UV/azo-bis(isobutyronitrile)-initiated addition of several secondary phosphines R2PH (R=Ph; Me, i-Pr, t-Bu, Cy) to the carbon-carbon double bonds of R'P(CH2CH=CH2)2 (R'=Me, t-Bu; Ph; CH2CH=CH2)2 P(CH2CH2CH=CH2)3, N(CH2CH=CH2)3, and As(CH2CH=CH2)3 was investigated with the aim of exploring the reaction scope. i-Pr2PH, t-Bu2PH, and Cy2 PH failed to add, or to completely add, to the allylphosphines chosen. Similarly, the hoped-for tripod tetratertiary ligands E(CH2CH2CH2PMe2)3 (E=N, As) could not be made accessible by coupling Me2PH onto triallylamine and triallylarsine, respectively. On the positive side, the facultative tri- and tetradentates t-BuP(CH2CH2CH2PPh2)2 and P(CH2CH2CH2CH2PMe2)2 have been obtained in high yields by irradiating mixtures of t-BuP(CH2CH˭CH2)2 or P(CH2CH2CH˭CH2)3 and excess Me2PH in the presence of catalytic amounts of azo-bis(isobutyronitrile). The rhodium complex RhCl[t-BuP(CH2CH2CH2PPh2)2)2] derived from one of these ligands was characterized by X-ray diffraction. Die...

HETEROPOLY ANION-ASSISTED Rh CATALYSIS REVEALED IN THE HOMOGENEOUS SELECTIVE HYDROGENATION

Abstract When coupled with lithium salt of heteropoly acid, the Wilkinson complex RhCl(PPh3)3 catalyst became very active and selective for the semihydrogenation of alkyne to alkene and, more interestingly, exhibited sharp substrate-selectivity in hydrogenation of substituted alkenes.

Homogeneous hydrogenation of dienes with rhodium complexes

AbstractDifferent Rh complex catalysts were compared for the hydrogenation of methyl sorbate and linoleate in the absence of solvents. At 100 C and 1 atm H2 the following complexes, RhCl(Ph3 P)3 (Ph= phenyl), [RhClNBD]2 (NBD=norbornadiene) and RhH(CO)(Ph3P)3, produced mainly methyltrans‐2‐hexenoate (34 to 56%). Their diene selectivity was not particularly high as they produced 14 to 41% methyl hexanoate. With RhCl(Ph3 P)3 constant ratios between rates of methyl sorbate disappearance and formation of methyltrans‐2‐ andtrans‐3‐hexenoate indicate approximately the same activation energy for 1,2‐addition of H2 on the Δ4 double bond of methyl sorbate and for 1,4‐addition to this substrate. In the hydrogenation of methyl linoleate with RhCl(Ph3 P)3, the kinetic curves were simulated by a scheme in which 1,2‐reduction was more than twice as important as 1,4‐addition of H2 via conjugated diene intermediates. Although the complexes RhCl(CO)(Ph3 P)3 and [Rh(NBD)(diphos)]+PF6 (diphos=diphosphine) were inactive in the hydrogenation of methyl sorbate, they catalyzed the hydrogenation of methyl linoleate at 100 C and 1 atm. Catalyst inhibition apparently was caused by stronger complex formation with methyl sorbate than with the conjugated dienes formed from methyl linoleate.

Oxidative addition of tetrabromo-1,2-benzoquinone totrans-carbonylchlorobis(triphenylphosphine)rhodium andtrans-carbonyliodiobis(triphenylphosphine)rhodium

The oxidative addition of tetrabromo-1,2-benzoquinone to Rh(CO)X(PPh3)2 (X = Cl or I) has been studied. With the square planar complex Rh(CO)Cl(PPh3)2, two new isomeric hexacoordinated compounds; withcis andtrans PPh3 ligands, have been isolated and their structures are discussed on the basis of spectroscopic data. Thecis isomer in acetone solution quickly converts into thetrans. Such a conversion presumably proceeds through the dissociation of a triphenylphosphine molecule as seems indicated by the isolation of the pentacoordinated intermediate species Rh(CO)I(PPh3)(1,2-O2C6Br4), which has been identified by elemental analysis and spectroscopically characterized.

Carbonyl rhodium(I) complexes with α-diimines ligands

The reactions of [Rh(CO) 2Cl] 2 with α-diimines, RN=CR′-CR′=NR (R = c-Hex, C 6H 5, p-C 6H 4OH, p-C 6H 4CH 3, p-C 6H 4OCH 3, R′ = H; R = c-Hex, C 6H 5, p-C 6H 4OH, p-C 6H 4OCH 3; R′ = Me) in 2:1 Rh/R-dim ratio gave rise to ionic compounds [(CO) 2Rh.R-dim(R′,R′)][Rh(CO) 2Cl 2] which have been characterized by elemental analyses, electrical conductivity, 1H-NMR and electronic and IR spectroscopy. Some of these complexes must involve some kind of metal-metal interaction. The complex [Rh(CO) 2Cl. c-Hex-dim(H,H)] has been obtained by reaction of [Rh(CO) 2Cl] 2 with the c-Hex-dim(H,H) ligand in 1:1 Rh/R-dim ratio. The reactions between [(CO) 2Rh.R-dim(H,H)][Rh(CO) 2Cl 2](R = c-Hex or p-C 6H 4OCH 3) with the dppe ligand have been studied. The known complex RhCl(CO)(PPh 3) 2 has been isolated from the reaction of [(CO) 2Rh.R-dim(H,H)]-[Rh(CO) 2Cl 2] (R = c-Hex or p-C 6H 4OCH 3) with PPh 3 ligand.

Enthalpy changes in oxidative addition reactions of iodine with monomeric and dimeric rhodium(I) complexes

The heat of reaction for addition of iodine to the planar complexes RhCl(CO)dppe, Rh(dppen) 2 +, Rh(dppe) 2 + and to the dimer Rh 2Cl 2(CO) 2(dppm) 2 has been obtained by a calorimetric method. Iodine forms stronger RhI bonds with RhCl(CO)dppe than with the bichelate complexes. The presence of metal-metal interaction in the iodine addition compound of Rh 2Cl 2(CO) 2(dppm) 2 makes a significant contribution to the enthalpy change for the oxidative addition. The stereochemistry of the complexes are discussed on the basis of IR and 31P NMR spectra.

Hydrogenation and isomerization of olefins on heterogenized rhodium complexes

The rhodium complex RhCl(PPh 3) 3 was bound to three types of phosphinated polystyrene which were prepared by copolymerization of styrene and diphenyl-para-styrylphosphine and by phosphination of rigid porous polystyrene beads. It was found by a temperature programmed reduction method that the complexes on these polymers are stabilized by supporting and that the chlorine ligand is removed by hydrogen activation treatment. X-ray photoelectron study showed that the oxidation state of the rhodium was Rh(II) and the removal of the chlorine atoms was confirmed. The catalytic properties of the polymer-bound complexes were studied for the hydrogenation and isomerization of olefins in the gas—solid heterogeneous system. The results were compared with those for the complex on silica and those in the homogeneous system. By heterogenizing on these solid supports, the selectivity for the isomerization of butene was generally enhanced. Catalytic activity for the hydrogenation was increased by anchoring on the rigid polymer or loading on silica, while it decreased remarkably by anchoring on the inner phosphine groups of the copolymer. In the latter case, the rate of hydrogenation decreased with increased in the chain length of olefins. Characteristic features observed for these reactions are discussed in terms of the availability of the sites, the structure of the actual species, and the carrier effects caused by binding.

Formation of diaryls by thermal decomposition of rhodium(I) triarylphosphine complexes

Chlorotris(triphenylphosphine)rhodium, RhCl(PPh 3) 3 undergoes thermal decomposition above 140°C in solution and in the solid state to yield biphenyl. Rhodium complexes with para-substituted triphenylphosphine ligands form exclusively 4,4′-disubstituted biphenyls. Mixtures of two complexes RhCl(PAr 3) 3 and RhCl(PAr′ 3) 3 form the crossed diaryl ArAr′ and two non-crossed compounds (Ar) 2 and (Ar′) 2. The mechanism is assumed to involve dissociation of RhCl(PPh 3) 3 into PPh 3 and solvated RhCl(Pph 3) 2 followed by oxidative addition of the liberated phosphine to the latter bis-triphenylphosphine compound. Evidence for a phenyl-rhodium intermediate has been provided by phenylation of styrene by RhCl(PPh 3) 3. In an independent process, RhCl(PPh 3) 3 forms benzene by an ortho-metallation route.

Hydrogenolysis of hydrazobenzene by reaction with 2-propanol in presence of triphenylphosphine complexes of rhodium and ruthenium

1. The complexes RhCl(PPh3)3 (I) and RuCl2(PPh3)3 (II) catalyze the transfer of hydrogen from 2-propanol to hydrogenolysis to form aniline. The addition of KOH to a solution of complex (I) promotes the hydrogenolysis of the N-N bond of hydrazobenzene. 2. The hydrogenolysis of hydrazobenzene by reaction with 2-propanol is substantially slower when catalyzed by alkali than when catalyzed by complexes (I) and (II).

Carbon-13 nuclear magnetic resonance study of rhodium(I) and -(III) and iridium(I) and -(III) complexes containing chelating unsaturated tertiary phosphines and arsines

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 nuclear magnetic resonance study of rhodium(I) and -(III) and iridium(I) and -(III) complexes containing chelating unsaturated tertiary phosphines and arsinesPeter W. Clark, Peter Hanisch, and Alan J. JonesCite this: Inorg. Chem. 1979, 18, 8, 2067–2075Publication Date (Print):August 1, 1979Publication History Published online1 May 2002Published inissue 1 August 1979https://doi.org/10.1021/ic50198a003RIGHTS & PERMISSIONSArticle Views168Altmetric-Citations26LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (985 KB) Get e-Alerts Get e-Alerts

Rhodium(III) and iridium(III) olefin complexes containing the tridentate ligand 1,6-bis(diphenylphosphino)- trans-hex-3-ene: crystal and molecular structure of trichloro-1,6-bis(diphenylphosphino)- trans-hex-3-eneiridium(III).

The olefin complexes RhCl 3(BDPH), RhClBr 2(BDPH), IrCl 3(BDPH), IrClBr 2(BDPH), IrCl(CH 3)I(BDPH), IrHCl 2(BDPH) and IrHBr 2(BDPH); BDPH = 1,6-bis(diphenylphosphino)- trans-hex-3-ene, have been prepared by oxidative-addition reactions of RhCl(BDPH) and IrCl(BDPH) and characterised by I.R. and 1H NMR spectra. A single crystal X-ray determination of the structure of IrCl 3(BDPH) shows the crystals to be orthorhombic, a = 16.1636(13), b = 20.2927(7), c = 17.1916(6)Å, Z = 8, space group Pbca, ϱ obs = 1.76, ϱ calc = 1.77 g cm −3. The structure was solved by conventional methods and refined by use of full-matrix least-squares equations to final residuals R = 0.041 and R w = 0.052 for 2926 observed reflections. The complex is monomeric with an octahedral coordination geometry consisting of the tridentate olefin(phosphine) 2 BDPH ligand (arranged such that the phosphorus atoms are mutually trans, and the three chloride ligands. Distances observed are Ir-P 2.382, 2.389(2)Å, Ir-Cl 2.358, 2.387 ( trans to olefin), 2.371(2)Å, Ir-C(olefin) 2.274, 2.277(10)Åf, C=C 1.352(14)Å. The olefin is inclined at an angle of 28° to the Ir, P(1), P(2), Cl(2) plane. The structure is compared and contrasted with the known structures of IrCl(BDPH) and IrH 2Cl(BDPH).

Reduction of azoxybenzene with 2-propanol in presence of triphenyl-phosphine complexes of rhodium and ruthenium

1. The complexes RhCl(PPh3)3 and RuCl2(PPh3)3 catalyze the transfer of hydrogen from 2-propanol to azoxybenzene with the formation of aniline. KOH promotes the process without changing its direction. 2. KOH also catalyzes the reduction of azoxybenzene in the absence of the Rh and Ru complexes, with the predominant formation of azobenzene and hydrazobenzene, but not of aniline.

Reduction of nitrobenzene by 2-propanol in presence of RhCl(PPh3)3 and RuCl2(PPh3)3

1. The complexes RhCl(PPh3)3 and RuCl2(PPh3)3 catalyze the reduction of nitrobenzene by 2-propanol to aniline at temperatures above 120°. This process is promoted by KOH. 2. In the absence of the indicated complexes, KOH catalyzes the reduction of nitrobenzene to azoxy-, azo-, and hydrazobenzene.

Trimethylphosphine complexes of rhodium(I) and ruthenium(II); X-ray crystal structures of chlorotristrimethylphosphinerhodium and tetrakistrimethylphosphinerhodium chloride

The syntheses are reported of the rhodium(I) and ruthenium(II) trimethylphosphine complexes RhCl(PMe3)3, [Rh(PMe3)4]Cl, η5-C5H5Rh(PMe3)2, CHg6Rh4(PMe3)12, trans-RuCl2(PMe3)4, [Ru2Cl2(PMe3)8]Cl2, and [RuCl(PMe3)4]BF4 and of ruthenium(I), Ru2Cl2(PMe3)4; the structures of RhCl(PMe3)3 and [Rh(PMe3)4]Cl have been determined by single crystal X-ray analysis.

ChemInform Abstract: NMR AND IR STUDIES OF THE BONDING PROPERTIES OF THE ETHYLENE‐RHODIUM COMPLEXES RHCL(C2H4)(L)(L′) (L = C2H4, CO, PR3, L′ = 2,6‐LUTIDINE)

Chemischer InformationsdienstVolume 9, Issue 47 Organoelement Compounds ChemInform Abstract: NMR AND IR STUDIES OF THE BONDING PROPERTIES OF THE ETHYLENE-RHODIUM COMPLEXES RHCL(C2H4)(L)(L′) (L = C2H4, CO, PR3, L′ = 2,6-LUTIDINE) A. MAISONNAT, A. MAISONNATSearch for more papers by this authorR. POILBLANC, R. POILBLANCSearch for more papers by this author A. MAISONNAT, A. MAISONNATSearch for more papers by this authorR. POILBLANC, R. POILBLANCSearch for more papers by this author First published: November 21, 1978 https://doi.org/10.1002/chin.197847290AboutPDF 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 onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume9, Issue47November 21, 1978 RelatedInformation

Cyclopentadienyl- and pentamethylcyclopentadienyl-rhodium(III) complexes containing isocyanide ligands

The complexes [(η 5-C 5H 5)RhCl 2] 2 and [(η 5-C 5Me 5)RhCl 2] 2 react with stoichiometric amounts of isocyanide ligands L to give (η 5-C 5H 5)RhLCl 2 and (η 5-C 5Me 5)RhLCl 2 (L = CNC 6H 11, CNC 6H 4CH 3- p); an excess of ligand L reacts further with (η 5-C 5Me 5)RhLCl 2 to give the cationic complex [(η 5-C 5Me 5)RhL 2Cl] + which was isolated as tetraphenylborate salt. The cationic complexes [(η 5-C 5Me 5)RhL(PPh 3)Cl] + and [(η 5-C 5Me 5)Rh(Ph 2PC 2H 4PPh 2)Cl] + were obtained in the reaction of (η 5-C 5Me 5)RhLCl 2 with PPh 3 and Ph 2PC 2H 4PPh 2 respectively. Unidentified solids which do not contain the cyclopentadienyl moiety were obtained in the analogous reactions of (η 5-C 5H 5)RhLCl 2 with an excess of isocyanide or of tertiary phosphine. The complexes (η 5-C 5H 5)Rh(CNC 6H 11)Cl 2 and (η 5-C 5Me 5)Rh(CNC 6H 11)Cl 2 react with SCN − or SeCN − giving the corresponding dithiocyanate or diselenocyanate derivatives in which the pseudohalogen groups are S- or Se-bonded to the metal atom. The analogous reactions with C 6Cl 5MgCl gave the chiral complexes (η 5-C 5H 5)Rh(CNC 6H 11)(C 6Cl 5)Cl and (η 5-C 5Me 5)Rh(CNC 6H 11)(C 6Cl 5)Cl. The potentially chelating anion Ph 2PSS − reacts with (η 5-C 5H 5)Rh(CNC 6H n11)Cl 2 and (η 5-C 5Me 5)Rh(CNC 6H 11)Cl 2 to give (η 5-C 5H 5)Rh(CNC 6H 11)(SSPPh 3)Cl and (η 5-C 5Me 5)Rh(CNC 6H 11)(SSPPh 2)Cl in which the dithio ligand acts as monodentate; these compounds react with MeI or EtI to give the dihalide derivatives and the esters Ph 2PSSMe and PSSEt. The complex [(η 5-C 5Me 5)Rh(CNC 6H 11)(SSPPh 2)]Cl was obtained by refluxing a benzene solution of the corresponding neutral complex; the cyclopentadienyl derivative failed to give the analogous chelate complex. The complexes (η 5-C 5H 5)RhLCl 2, (η 5-C 5Me 5)RhLCl 2 and [(η 5-C 5Me 5)RhL 2Cl] + (L = CNC 6H 11) were found to be unreactive towards amines.

Relative stabilities of acyl- and formyl-rhodium complexes

The various complexes RhCl 2(COR)(PPh 3) 2 and/or RhRCl 2CO(PPh 3) 2 (R  H, Me, Et, n-Pr, CH 2Cl, CH 2Ph, CH 2CH 2Ph, Cl) are generated in solution, and factors affecting the positions of equilibrium between the five-coordinate and six-coordinate isomers are discussed. The complex RhCl 2(COMe)[(Ph 2P) 2(CH 2) 3] is far more stable with respect to isomerization to a six-coordinate methyl isomer than are any of the triphenylphosphine complexes studied.

Synthese et proprietes catalytiques de quelques complexes rhodium—(+) diop

The reaction of Rh 2Cl 2(C 2H 4) 4 with (+)-DIOP in benzene as solvent leads to isolation of the compound [RhCl(DIOP)(C 6H 6)] 2 which is highly air-sensitive even in the solid state and gives an oxidized complex which can be reactivated in the presence of hydrogen. Carbon monóxide transforms it into the carbonyl complex RhCl(CO)(DIOP), while a non-coordinating anion in alcoholic medium leads to the cationic complex: Rh(DIOP)(C 2H 5OH) 2 +B(C 6H 5) 4 −. The catalytic properties of these complexes in the asymmetric hydrogenation reaction have been tested. Optical rotation measurements were made under various conditions, and allowed some assumptions about the equilibria which exist in the hydrogenation reaction medium.