Transition Metal Carbon Research Articles

Remarks on the stability of transition metal–carbon bonds

Evidence is compiled which suggests that σ bonds between transition metals and one-electron carbon donors are not weak. Lability of such bonds, in so far as it is a real phenomenon, cannot be explained in terms of the orthodox π-ligand stabilisation theory, although an electron promotion mechanism of a different type may operate in some cases. The importance for thermal decomposition of concerted mechanisms such as β-elimination, reductive elimination, and binuclear interactions is emphasised.

Transition metal–carbon bond lability and electronic configuration: a comment

Theoretical explanations of transition metal-carbon bond lability, in terms of configuration inter-action among dn states along the reaction co-ordinates for homolysis, require closer critical scrutiny.

Insertion of chlorosulphonyl isocyanate into a transition-metal–carbon bond

A novel dicarbonyl-π-cyclopentadienylironamido-complex, cpFe(CO)2[N(SO2Cl)C(O)CH2C(Me)= CH2](cp =π-cyclopentadienyl), is the product of the first reported insertion of chlorosulphonyl isocyanate into a transition-metal–carbon bond; this reaction is believed to proceed via a dipolar iron–olefin complex.

The influence of metal electronic configuration on the activation energy for transition-metal–carbon bond dissociation

Symmetry arguments suggest that metal electronic configuration can influence the activation energy for metal–carbon homolytic bond dissociation.

Organoetallic chemistry of the transition metals XXVII. Some new rhodium complexes of allene pentamer (1,2,5,6,8-pentamethyenecyclodecane)

Several reactions of rhodium(I) complexes of 1,2,5,6,8-pentamethylenecyclodecane (allene pentamer, C 15H 20) are described. Reaction of the chloride C 15H 20RhCl with (pentafluorophenyl)lithium in diethyl ether gives the yellow crystalline σ-pentafluorophenyl derivative C 15H 20RhC 6F 5, apparently the first known example of a derivative with a transition metalcarbon σ-bond where all of the other ligands are coordinated carboncarbon double bonds. Reaction of C 15H 20RhCl with sodium cyclopentadienide in tetrahydrofuran solution gives yellow waxy C 15H 20RhC 5H 5 shown by its NMR spectrum to have a tetrahapto-1,2,5,6,8-pentamethylenecyclodecane ligand and a pentahapto-cyclopentadienyl ligand. The predominant ion in the mass spectrum of C 15H 20RhC 5H 5 is C 15H 20Rh + which is formed by loss of C 5H 5 from the molecular ion. Reaction of C 15H 20RhCl with stannous chloride in diethyl ether gives yellow C 15H 20RhSnCl 3. Reaction of C 15H 20RhCl with silver hexafluorophosphate in acetone solution gives the yellow salt [C 15H 20Rh][PF 6]. This salt reacts with carbon monoxide at atmospheric pressure to give the yellow monocarbonyl [C 15H 20RhCO][PF 6], which can also be obtained by reaction of C 15H 20RhCl with carbon monoxide in boiling ethanol followed by reaction with ammonium hexafuorophosphate in aqueous acetone.

The diversity of behavior of tetracyanoethylene toward transition metalcarbon σ-bonded complexes

The diversity of behavior of tetracyanoethylene toward transition metalcarbon σ-bonded complexes

Ring expansions in the reactions of transition metal-carbon .sigma.-bonded chelate complexes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRing expansions in the reactions of transition metal-carbon .sigma.-bonded chelate complexesM. A. Bennett, Kathleen Hoskins, W. R. Kneen, R. S. Nyholm, R. Mason, P. B. Hitchcock, G. B. Robertson, and A. D. C. TowlCite this: J. Am. Chem. Soc. 1971, 93, 18, 4592–4594Publication Date (Print):September 1, 1971Publication History Published online1 May 2002Published inissue 1 September 1971https://doi.org/10.1021/ja00747a043RIGHTS & PERMISSIONSArticle Views60Altmetric-Citations19LEARN 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 (342 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: ZUR KENNTNIS VON DITHIOCARBOXYLAT‐KOMPLEXEN DES MANGANS UND RHENIUMS

AbstractUnter strengstem Sauerstoffausschluß reagiert Schwefelkohlenstoff beim Erhitzen im Einschlußrohr mit den Organometallcarbonylen (I), (IV), (VI) und (VIII) unter CS2‐Einschiebung in die Metall‐Kohlenstoff‐Bindung zu den Dithiocarboxylaten (II), (V), (VII) und (IX).

Transition metal–carbon bonds. Part XXVII. Oxidative addition reactions of [PtMe2(dias)], dias o-phenylenebis(dimethylarsine)

[PtMe2(dias)] is shown to undergo oxidative addition reactions with alkyl or acyl halides at least as readily as a corresponding complex with a monodentate ligand such as cis-[PtMe2(AsMe2Ph)2]. Acyl halides add trans to give platinum (IV) adducts, [PtXRMe2(dias)](X = halogen; R = acetyl or benzoyl) but allylic halides add cis(R = allyl or 2-methylallyl). The stereochemistries follow from the 1H n.m.r. and i.r. spectra. These complexes show interesting correlations between values of J(195Pt–CH3), τCH3, ν(Pt–C), ν(Pt–Cl) and δs(CH3).

Transition metal–carbon bonds. Part XXIX. Some internal metallation reactions of tertiary phosphine ligands with bulky substituents

Complexes of the type trans-[PtX2L2][X = Cl, Br, or I; L = PButPh2, PBut(p-tolyl)2, PBut2Ph, PBut2(p-tolyl), PButPrn2, PBut2Prn, PPh(o-tolyl)2, or PMe2(o-tolyl)] have been prepared. Bulky substitents on tertiary phosphine ligands, e.g. t-butyl or o-tolyl, promote internal platinum–carbon bond formation to give complexes of the type trans-[PtX(P–C)L][X = Cl, Br, or I; (P–C)= internally metallated tertiary phosphine; L = tertiary phosphine]. Tertiary phosphine ligands with two t-butyl groups undergo internal metallation (ring-closure) more readily than those with only one t-butyl group. o-Tolylphosphines can also promote ring-closure reactions but the tertiary phosphines with smaller steric requirements show no tendency to metallate internally. The internal metallation reactions give five-membered rings if possible. Generally, the tendency to internally metallate increased in the order of anionic ligands Cl < Br < I. The corresponding palladium(II) complexes, trans-[PdX2L2](X = Cl, Br, or I; L = bulky tertiary phosphine) show no tendency to form internal metal–carbon bonds.

Zur kenntnis von dithiocarboxylat-komplexen des mangans und rheniums

The insertion of CS 2 in transition metalcarbon σ-bonds can be carried out generally for organometallic carbonyls of Group VII metals, as is demostrated by numerous examples. The structure and bonding of these new dithiocarboxylate complexes of manganese and rhenium, prepared in this way, are discussed on the basis of their mass, 1H NMR and IR spectra.

Transition metal–carbon bonds. Part XXI. Methyl derivatives of platinum(II) and platinum(IV) containing dimethylphenylarsine as ligand

Methylplatinum(II) complexes of the types cis-[PtMe2(AsMe2Ph)2] and trans-[PtXMe(AsMe2Ph)2](X = halogen), and methylplatinum(IV) complexes of the type [PtX4–nMen(AsMe2Ph)2](X = halogen, n= 1–4) are described. The stereochemistries follow from the methyl resonance patterns in the n.m.r. spectra and are confirmed by dipole moment and i.r. spectral measurements. Values of δ(Me) for the platinum-bonded methyl groups, ν(Pt–C), ν(Pt–Cl), τ(Me) and J(Pt–H) are given and discussed.

Transition metal–carbon bonds. Part XX. Methyl derivatives of platinum-(II) and -(IV) containing tertiary phosphines as ligands

Methylplatinum(II) complexes of the types cis-PtMe2L2, cis-PtXMeL2 and trans-PtXMeL2(X = halogen; L = PMe2Ph or PMePh2) and methylplatinum(IV) complexes of the type PtX4–nMen(PMe2Ph)2(X = halogen, n= 1–4) are described. The stereochemistries are derived from the methyl resonance patterns in the n.m.r. spectra and are confirmed by dipole moment and i.r. spectral measurements. Values of δs(Me) for the platinum-bonded methyl groups, ν(Pt–C), ν(Pt–Cl), τ(Me), J(P–H) and J(Pt–H) are given and discussed.

Transition metal–carbon bonds. Part XVIII. Allylic and related complexes of palladium derived from hexamethyl Dewar benzene

Hexamethyl Dewar benzene complexes of palladium of the type [PdX2(C12H18)](X = Cl or Br) are described in which the hexamethyl Dewar benzene is acting as a chelating diolefin. These complexes react with sodium methoxide in methanol to give halogen-bridged complexes of the type [Pd2X2(C12H17)2] in which the ligand C12H17 still retains the carbon framework of hexamethyl Dewar benzene but acts as a π-allylic ligand. Various derivatives of the type [PdXL(C12H17)](L = PPh3, AsPh3, PMe2Ph, or isoquinoline) and [PdY(C12H17)](Y = acetylacetonate or C5H5) are described. I.r. and n.m.r. spectroscopic data are given. Complexes of the type [Pd2X2(C12H17)2] react with PMe2Ph (1–2 mol. per Pd atom) to cause magnetic equivalence of the allylic hydrogens via a σ-allylic complex.

Transition metal–carbon bonds. Part XVI. Cationic allylic complexes of palladium(II). A cationic allylic complex of platinum(II)

In aqueous acetone [Pd2Cl2(2-methylallyl)2] reacts with PPh3 to give the colourless cation [Pd(2-methylallyl)(PPh3)2]+, isolated as its tetraphenylborate salt. Similar complexes with PMe2Ph and AsMe2Ph were prepared. Treatment of [PdCl2(PPh3)2] with 2-methylallylmagnesium chloride followed by hydrolysis gave the hydrated chloride [Pd(2-methylallyl)(PPh3)2]Cl·2H2O. Attempts to prepare analogous complexes with other allylic ligands were unsuccessful. N.m.r. data show the 2-methylallyl ligands in these cations to be symmetrically π-bonded to the palladium. Conductimetric studies on systems of the type [Pd2X2 all2]+x mol. of L have shown that the tendency to form ionic species decreases (1) for different ligands L in the order PMe2Ph ∼ PEt2Ph ∼ PEt3 > PPh3 > AsPh3 > SbPh3 > pyridine; (2) for different allyl ligands ‘all’ in the order 2-methylallyl > allyl > 1-methylallyl > 1,3-dimethylallyl > 1,1-dimethylallyl; and (3) for different halogens X in the order Cl > Br > I. Compounds of the type [Pd2Cl2 all2] react rapidly with an excess of PPh3 in aqueous acetone to give [Pd(PPh3)4] and [all PPh3]+ Cl–. Treatment of [Pd(PPh3)4] with an excess of the allylic chloride gives [PdCl all PPh3].Treatment of [PtCl2(AsMe2Ph)2] with 2-methylallylmagnesium chloride followed by water and NaBPh4 gave the salt [Pt(2-methylallyl)(AsMe2Ph)2]+ BPh4–.

Transition metal–carbon bonds. Part XIV. Allylic complexes of rhodium

Download options Please wait... Article information DOI https://doi.org/10.1039/J19680000583 Article type Paper Download Citation J. Chem. Soc. A, 1968, 583-596 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Transition metal–carbon bonds. Part XIV. Allylic complexes of rhodium J. Powell and B. L. Shaw, J. Chem. Soc. A, 1968, 583 DOI: 10.1039/J19680000583 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author J. Powell B. L. Shaw

Transition metal–carbon bonds. Part X. Reactions between allylic palladium halides and tertiary phosphines, triphenylarsine, triphenylstibine, or carbon monoxide

A series of complexes of the type [PdX(all)L](X = halogen, all = allylic ligand, and L = tertiary phosphine, triphenylarsine, or triphenylstibine) is described and the asymmetric bonding of the allylic ligand discussed. Several fast rate processes occur in solutions containing allylic palladium halides [Pd2X2(all)2] and neutral ligands L (e.g., phosphines) as the ratio L/Pd is varied from 0 to ca. 2 and these have been studied by n.m.r. spectroscopy at 34°. These fast rate processes involve the conversion of the π-allylic complexes into dynamic σ-allylic systems in which various rotations about carbon–carbon and palladium–carbon bonds and also exchange of the co-ordinated ligand L with free ligand occur. Co-ordination of dimethylphenylphosphine to the palladium atom of [Pd2Cl2(2-methylallyl)2] has been studied both by n.m.r. and by osmometry and at least two dimethylphenylphosphine ligands can become co-ordinated to the palladium, with the probable formation of [PdCl(σ-2-methylallyl)-(PMe2Ph)2] in solution. Carbon monoxide will also co-ordinate to the palladium atom of [Pd2Cl2(2-methylallyl)2], the n.m.r. spectrum in chloroform solution corresponding to that of a ‘dynamic’σ-2-methylallylic system.

Transition metal–carbon bonds. Part IX. Oxidative addition reactions of cyclo-octeneiridium(I) complexes

Download options Please wait... Article information DOI https://doi.org/10.1039/J19670001683 Article type Paper Download Citation J. Chem. Soc. A, 1967, 1683-1693 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Transition metal–carbon bonds. Part IX. Oxidative addition reactions of cyclo-octeneiridium(I) complexes B. L. Shaw and E. Singleton, J. Chem. Soc. A, 1967, 1683 DOI: 10.1039/J19670001683 To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page. If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given. If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page. Read more about how to correctly acknowledge RSC content. Search articles by author B. L. Shaw E. Singleton

Transition metal–carbon bonds. Part VIII. Methyl derivatives of iridium(III) containing dimethylphenylphosphine or dimethylphenylarsine as ligands

Methyliridium(III) complexes of the type [IrXx(Me)3–xL](X = halogen; x= 0–2; L = PMe2Ph or AsMe2Ph) are described. The methyl resonance patterns in the nuclear magnetic resonance spectra are very useful in assigning stereochemistries. Some dipole moments are given and discussed. Values of (1) methyl deformation frequencies (δMe) for the iridium-bonded methyls, (2) iridium–carbon stretching frequencies, and (3) iridium–chlorine stretching frequencies are given and discussed.

Transition metal–carbon bonds. Part VII. The formation of π-allylic–palladium complexes from allenes and palladium halides and the reversed reactions

The formation of bridged-chloro- 2-chloroprop-2-enyl- and β-(3-chloroprop-1-en-2-yl)allyl-palladium(II) complexes by reacting allene with palladium(II) chloride complexes are described. Similar reactions of methylallene and 1,1-dimethylallene are also described. The resultant bridged-chloro-π-allylic complexes undergo reactions such as metathesis and conversion to monomeric acetylacetonates and also bridged splitting reactions with amines or tertiary phosphines. Under certain conditions, the β-halo π-allylic complexes can eliminate allenes on reaction with ammonia or tertiary phosphines. The mechanisms of the formation of π-allylic complexes from allenes and palladium(II) halide complexes are discussed as are the reversed reactions, e.g., elimination of allene from β-haloallyl complexes. Nuclear magnetic resonance data are given.