Intramolecular Ligand Exchange Research Articles

Variable temperature 1H NMR studies of [M(COD)(μ-L)] 2 (M  Rh, Ir; L = substituted hydroxypyridinate). Facile intramolecular bridging ligand exchange and metal-metal bond cleavage

The variable temperature 1H NMR spectra of [M(COD)(μ-L)] 2 (M  Rh, Ir: L = 2-hydroxypyridinate (μ-hp), 6-methyl-2-hydroxypyridinate (mhp)) in toluene- d 8 solutions are described. Our analysis of the 1H NMR spectra indicates that the binuclear hydroxypyridinate complexes undergo fluxional processes significantly different than previously studied mononuclear analogues. Two distinct exchange processes interconvert nonequivalent COD protons in [Rh(COD)(μ-hp)], but only the lower energy process is observed in [Ir(COD)(μ-hp)] 2. The resonances of the bridging ligands are essentially unaffected by temperature changes. The low energy process (process 1) interconverts COD hydrogens trans to N with those trans to O, but does not interconvert “inside” with “outside”ogens. The second process (process 2), observed for [Rh(COD)(μ-hp)] 2, interconverts inside with outside protons. Line shape analyses of the variable temperature spectra of the hp complexes yielded the rates and activation parameters of processes 1 and 2. Analogous behavior was observed for [Ir(COD)(μ-mhp)] 2 and [Rh(COD)(μ-mhp)] 2. No exchange behaviour was observed in the spectrum of the related complex, [Ir(COD)(μ-pz)] 2. The effects of concentration, added COD, and added nucleophile (acetonitrile) on the rates of exchange are discussed. “Cross-over” experiments, in which two different [M(COD)(μ-L)] 2 species were mixed together, demonstrate that process 1 is strictly intramolecular. The rotation and/or dissociation of COD ligands, the complete dissociation of the bridging ligands and the rupture of the M-M interaction are not involved with process 1. Process 1 must involve only motion of the bridging ligands, and does not involve the formation of mononuclear intermediates. For process 2, dissociation of COD was ruled out, but the rotation of the coordinated diene or the inversion of the 8-membered metallocyclic ring are viable mechanisms. Cross-over experiments show that at temperatures where the rate of process 2 is appreciable, metal-metal and bridging ligand exchange occurs. These results, and the large positive entropy of activation of process 2 in [Rh(COD)(μ-hp)] 2 imply a dissociative mechanism. Process 2 has a substantially higher activation barrier in [Ir(COD)(μ-hp)] 2 than in [Rh(COD)(μ-hp)] 2, consistent with the stronger M-M interaction expected for the Ir 2 complex. Both proposed pathways for process 2 involve substantial weakening of the M-M interaction.

Pentacoordinated molecules. 77. Intramolecular ligand exchange of pentacoordinated anionic silicates, RSiF4-, via silicon-29 and fluorine-19 NMR spectroscopy. Solution- and solid-state structures

Pentacoordinated molecules. 77. Intramolecular ligand exchange of pentacoordinated anionic silicates, RSiF4-, via silicon-29 and fluorine-19 NMR spectroscopy. Solution- and solid-state structures

Pentacoordinated molecules. 78. Intramolecular ligand exchange of pentacoordinated anionic silicates, R2SiF3-, via silicon-29 and fluorine-19 NMR spectroscopy. Solution- and solid-state structures

Pentacoordinated molecules. 78. Intramolecular ligand exchange of pentacoordinated anionic silicates, R2SiF3-, via silicon-29 and fluorine-19 NMR spectroscopy. Solution- and solid-state structures

Transition metal substituted phosphanes, arsanes and stibanes. XLII[1] Thermal treatment of Cp(OC) 3 W-substituted arsanes and arsinesulfides: inter- and intramolecular ligand exchange with co-substitution

Etude des substitutions (dicarbonylation) de CpW(CO) 3 -As(i-Pr) 2 : il y a formation d'heterocycles a 4 membres (avec liaison W−AS−W−As)

Synthesis and redox chemistry of octaethylporphyrin complexes of ruthenium(II) and ruthenium(III)

The syntheses and characterization of some new octaethylporphyrin complexes of ruthenium(II) and ruthenium(III) are described; the complexes are Ru(OEP)(P″Bu3)2, Ru(OEP)(CO)L (L = PPh3, P″Bu3), [Ru(OEP)(P″Bu3)2]Br, and Ru(OEP)(P″Bu3)Br, where OEP is the dianion of octaethylporphyrin. The Ru(OEP)(CO)EtOH complex, 1, which reversibly loses the ethanol ligand in CH2Cl2 solution, undergoes a one-equivalent oxidation at the porphyrin ligand to generate the cation-radical [Ru(OEP)•+(CO)]+; a purple species of 2A2u ground state, produced electrochemically in perchlorate media, can coordinate bromide to generate a green 2A1u ground state species that also results from oxidation of 1 using bromine. Coordination of pyridine to [Ru(OEP)•+(CO)]+ yields the Ru(OEP)•+(CO)py species that can also be formed by electrochemical oxidation of Ru(OEP)(CO)py. Addition of tertiary phosphines (PR3) to the cation-radical carbonyl species can lead to formation of [Ru(OEP)(PR3)2]+, via an internal electron transfer process from Ru(II) to the OEP•+ that appears to be triggered by loss of the CO ligand. A reversible one-electron electrochemical oxidation of Ru(OEP)(P″Bu3)2 at 0.03 V (vs. Ag/AgCl) in CH2Cl2 also gives the ruthenium(III) biphosphine cation, while a further one-electron oxidation at 1.2 V generates [Ru(OEP)•+(P″Bu3)2]2+, a ruthenium(III) π-cation radical characterized by esr. The [Ru(OEP)(P″Bu3)2]Br complex decomposes in the solid state to a mixture of Ru(OEP)(P″Bu3)Br, formed together with free phosphine via an intramolecular ligand exchange, and Ru(OEP)(P″Bu3)2, formed by reduction of the initial ionic ruthenium(III) cation with the phosphine that appears as [P″Bu3Br]Br.

Detection of pseudorotation in dimers of pentaalkoxy derivatives of antimony on the basis of PMR spectrometric data

1. A mechanism has been proposed for intramolecular and intermolecular ligand exchange in a series of pentacoordinated derivatives of Sb. 2. An interpretation has been given for the temperature dependence of the NMR spectra within the framework of concepts as to the limiting stages of equilibrium reactions. 3. Activation energies have been determined for the process of rupture and formation of the dimeric bond, and an estimate has been made of the lower limit of free energy of activation of pseudorotation in the monomeric pentacoordinated form.

Stereomutation at pentacoordinate silicon by intramolecular ligand exchange

Stereomutation at pentacoordinate silicon by intramolecular ligand exchange

On the use of 13C 13C coupling in establishing intramolecular versus intermolecular CO ligand reaarangement processes in metal carbonyl derivatives

13C 13C spinspin coupling between axial and equatorial CO ligands in M(CO) 5L(M = Group VIB metal) derivatives is employed in establishing intramolecular versus intermolecular axialequatorial carbon monoxide ligand exchange pathways.

ChemInform Abstract: NMR STUDY OF INTRAMOLECULAR AND INTERMOLECULAR LIGAND EXCHANGE IN PHENYLTRIFLUOROPHOSPHORANE

Chemischer InformationsdienstVolume 11, Issue 28 Organoelement Compounds ChemInform Abstract: NMR STUDY OF INTRAMOLECULAR AND INTERMOLECULAR LIGAND EXCHANGE IN PHENYLTRIFLUOROPHOSPHORANE R. K. MARAT, R. K. MARATSearch for more papers by this authorA. F. JANZEN, A. F. JANZENSearch for more papers by this author R. K. MARAT, R. K. MARATSearch for more papers by this authorA. F. JANZEN, A. F. JANZENSearch for more papers by this author First published: July 15, 1980 https://doi.org/10.1002/chin.198028255AboutPDF 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. Volume11, Issue28July 15, 1980 RelatedInformation

NMR study of intramolecular and intermolecular ligand exchange in phenyltrifluorophosphorane

NMR study of intramolecular and intermolecular ligand exchange in phenyltrifluorophosphorane

Evidence for an oscillating intramolecular ligand exchange mechanism due to an alternation between two identically strong aliphatic hydrogen to palladium interactions

Evidence for an oscillating intramolecular ligand exchange mechanism due to an alternation between two identically strong aliphatic hydrogen to palladium interactions

Stereochemical non-rigidity of phosphoranyl radicals: relative ligand apicophilicities

A series of phosphoranyl radicals, produced by addition of photochemically generated alkoxyl or benzoyloxyl radicals to substituted 1,3,2-dioxaphospholans, have been studied by e.s.r. spectroscopy. The spectra of certain of these radicals exhibit line-shape effects which are interpreted in terms of intramolecular ligand exchange at phosphorus. On the basis of deuterium labelling studies, two types of apical–equatorial ligand exchange have been identified, involving interchange of exocyclic or of endocyclic substituents, respectively. The spectra derived from 4,4-dimethyl-1,3,2-dioxaphospholans show the presence of an approximately equimolar mixture of two isomeric phosphoranyl radicals, in, which the endocyclic CH2O group is sited either apically or equatorially. The e.s.r. spectra of some cyclic and acyclic phosphoranyl radicals show that, in general, ligand apicophilicity decreases in the order F–, Cl–, RC(O)O–>[graphic omitted]–, OCN–> RO–, R2N>H–>H3C–, closely paralleling group electronegativity. Rate constants for exchange of apical with equatorial H and Me2N ligands, repectively, in the acyclic radicals H2(Me)ṖOBut and (Me2N)2ClṖOBut have been estimated.

Intramolecular ligand exchange in phosphoranes. A comparison of Berry pseudorotation and turnstile rotation

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTIntramolecular ligand exchange in phosphoranes. A comparison of Berry pseudorotation and turnstile rotationJulianna A. Altmann, Keith Yates, and I. G. CsizmadiaCite this: J. Am. Chem. Soc. 1976, 98, 6, 1450–1454Publication Date (Print):March 1, 1976Publication History Published online1 May 2002Published inissue 1 March 1976https://doi.org/10.1021/ja00422a028RIGHTS & PERMISSIONSArticle Views157Altmetric-Citations42LEARN 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 (520 KB) Get e-Alerts Get e-Alerts

Correlated intermolecular and intramolecular ligand exchange in .mu.-acetylene-bis(ligand)tetrakis(trifluorophosphine)dirhodium complexes and the crystal and molecular structure of the diphenylacetylene-triphenylphosphine derivative Rh2(PF3)4[P(C6H5)3]2(C6H5C2C6H5).(C2H5)2O

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCorrelated intermolecular and intramolecular ligand exchange in .mu.-acetylene-bis(ligand)tetrakis(trifluorophosphine)dirhodium complexes and the crystal and molecular structure of the diphenylacetylene-triphenylphosphine derivative Rh2(PF3)4[P(C6H5)3]2(C6H5C2C6H5).(C2H5)2OM. A. Bennett, R. N. Johnson, G. B. Robertson, T. W. Turney, and P. O. WhimpCite this: Inorg. Chem. 1976, 15, 1, 97–107Publication Date (Print):January 1, 1976Publication History Published online1 May 2002Published inissue 1 January 1976https://doi.org/10.1021/ic50155a021RIGHTS & PERMISSIONSArticle Views20Altmetric-Citations28LEARN 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 (1 MB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

On the evidence for intramolecular ligand exchange in pentacoordinate carbonate (IV) anion: Implications for the mechanism of bimolecular nucleophilic substitution at saturated carbon.

On the evidence for intramolecular ligand exchange in pentacoordinate carbonate (IV) anion: Implications for the mechanism of bimolecular nucleophilic substitution at saturated carbon.

Unusual intermolecular ligand exchange process in octakis(trimethylphosphite)dirhodium(0), Rh2[P(OMe)3

The new complex Rh2[P(OMe)3]8 which has a bicapped trigonal antiprismatic structure at room temperature undergoes a specific equatorial intermolecular ligand exchange at higher temperatures rather than any intramolecular ligand exchange between equatorial and axial sites.

Intramolecular exchange in vanadium pentafluoride

Anharmonicity data derived from observed hot band structure for the ν7 fundamental of VF5 has resulted in a 1.8 kcal/mol (7.7 kJ mol–1) barrier associated with the intramolecular ligand exchange process.

Intramolecular and intermolecular ligand exchange in five-co-ordinate cobalt(I) complexes

Download options Please wait... Article information DOI https://doi.org/10.1039/C39730000221 Article type Paper Download Citation J. Chem. Soc., Chem. Commun., 1973, 221-222 BibTex EndNote MEDLINE ProCite ReferenceManager RefWorks RIS Permissions Request permissions Intramolecular and intermolecular ligand exchange in five-co-ordinate cobalt(I) complexes E. L. Muetterties, J. Chem. Soc., Chem. Commun., 1973, 221 DOI: 10.1039/C39730000221 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 Earl L. Muetterties

Inter- and intramolecular ligand exchange reactions of ruthenium(II) carbonyl porphine complexes with nitrogen bases

To investigate both inter- and intramolecular site exchange in coordinated nitrogenous bases the complexes of tetra( p-isopropylphenyl)porphinato ruthenium carbonyl with4-tert-butylpyridine, 2-methylpyridine, 3,5-dimethylpyrazole, 4,5-dimethylpyridazine, and 3,6-dimethylpyridazine have been studied by total line shape analysis of the variable temperature PMR spectra. Both types of exchange mechanisms have been found in these complexes. All of the complexes undergo intermolecular ligand exchange at rates ranging from ∼0.09 sec −1 (Δ G ≠ ∼ 19 kcal/mol) to 2 × 10 4 sec − (Δ G ≠ ∼ 12 kcal/mol) at 25° for the various complexes, independent of the concentration of excess ligand. Thus the rate determining step is dissociation. The two pyridazine complexes provide the first examples of intramolecular ligand exchange with coordinated nitrogenous bases. The rates at 25° for intramolecular site exchange (∼10 6 and 66 sec −1) are 20–85 times faster than the rates for intramolecular ligand exchange in the same complexes. Within experimental uncertainty there is no intramolecular ligand site exchange in the 3,5-dimethylphyrazole complex. Full kinetic and mechanistic details are discussed.

Electronic structure of PH5 and intramolecular ligand exchange in phosphoranes. Model studies

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic structure of PH5 and intramolecular ligand exchange in phosphoranes. Model studiesArvi Rauk, Leland C. Allen, and Kurt MislowCite this: J. Am. Chem. Soc. 1972, 94, 9, 3035–3040Publication Date (Print):May 1, 1972Publication History Published online1 May 2002Published inissue 1 May 1972https://doi.org/10.1021/ja00764a026RIGHTS & PERMISSIONSArticle Views295Altmetric-Citations67LEARN 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 (667 KB) Get e-Alerts Get e-Alerts