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Xamonaki N, Asimakopoulos A, Balafas A, Dasenaki M, Choinopoulos I, Coco S, Simandiras E, Koinis S. Tetrathiomolybdate Complexes of Rhodium(I) with Molybdenum–Rhodium Interactions. Inorg Chem 2016; 55:4771-81. [DOI: 10.1021/acs.inorgchem.6b00072] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Nikoletta Xamonaki
- Faculty of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | | | - Anastasios Balafas
- Faculty of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Marilena Dasenaki
- Faculty of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Ioannis Choinopoulos
- Faculty of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
| | - Silverio Coco
- IU/CINQUIMA, Quı́mica Inorgánica,
Facultad de Ciencias, Universitad de Valladolid, 47071 Valladolid, Spain
| | - Emmanuel Simandiras
- Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 11635 Athens, Greece
| | - Spyros Koinis
- Faculty of Chemistry, National and Kapodistrian University of Athens, 15771 Athens, Greece
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Affiliation(s)
- William E. Geiger
- Department of Chemistry, University of Vermont, Burlington, Vermont 05405
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Romeo R, Carnabuci S, Plutino MR, Romeo A, Rizzato S, Albinati A. Structural Properties and Dissociative Fluxional Motion of 2,9-Dimethyl-1,10-Phenanthroline in Platinum(II) Complexes. Inorg Chem 2005; 44:1248-62. [PMID: 15732965 DOI: 10.1021/ic0485920] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A dynamic 1H NMR study has been carried out on the fluxional motion of the symmetric chelating ligand 2,9-dimethyl-1,10-phenanthroline (Me2-phen) between nonequivalent exchanging sites in a variety of square-planar complexes of the type [Pt(Me)(Me2-phen)(PR3)]BArf, 1-14, (BArf = B[3,5-(CF3)2C6H3]4). In these compounds, the P-donor ligands PR3 encompass a wide range of steric and electronic characteristics [PR3 = P(4-XC6H4)3, X = H 1, F, 2, Cl 3, CF3 4, MeO 5, Me 6; PR3 = PMe(C6H5)2 7, PMe2(C6H5) 8, PMe3 9, PEt3 10, P(i-Pr)3 11, PCy(C6H5)2 12, PCy2(C6H5) 13, PCy3 14]. All complexes have been synthesized and fully characterized through elemental analysis, 1H and 31P{1H} NMR. X-ray crystal structures are reported for the compounds 8, 11, 14, and for [Pt(Me)(phen)(P(C6H5)3)]PF6 (15), all but the last showing loss of planarity and a significant rotation of the Me2-phen moiety around the N1-N2 vector. Steric congestion brought about by the P-donor ligands is responsible for tetrahedral distortion of the coordination plane and significant lengthening of the Pt-N2 (cis to phosphane) bond distances. Application of standard quantitative analysis of ligand effects (QALE) methodology enabled a quantitative separation of steric and electronic contributions of P-donor ligands to the values of the platinum-phosphorus 1J(PtP) coupling constants and of the free activation energies DeltaG++ of the fluxional motion of Me2-phen in 1-14. The steric profiles for both 1J(PtP) and DeltaG++ show the onset of steric thresholds (at cone angle values of 150 degrees and 148 degrees , respectively), that are associated with an overload of steric congestion already evidenced by the crystal structures of 11 and 14. The sharp increase of the fluxional rate of Me2-phen can be assumed as a perceptive kinetic tool for revealing ground-state destabilization produced by the P-donor ligands. The mechanism involves initial breaking of a metal-nitrogen bond, fast interconversion between two 14-electron three-coordinate T-shaped intermediates containing eta1-coordinated Me2-phen, and final ring closure. By use of the results from QALE regression analysis, a free-energy surface has been constructed that represents the way in which any single P-donor ligand can affect the energy of the transition state in the absence of aryl or pi-acidity effects.
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Affiliation(s)
- Raffaello Romeo
- Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica, Università di Messina, Salita Sperone 31, Vill. S. Agata 98166, Messina, Italy.
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Reyes C, Prock A, Giering WP. Analysis of the enantioselectivities and initial rates of the hydrosilylation of acetophenone catalyzed by [Rh(cod)Cl]2/(chiral diphosphine). The quantitative analysis of ligand effects. J Organomet Chem 2003. [DOI: 10.1016/s0022-328x(02)02221-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Romeo R, Fenech L, Carnabuci S, Plutino MR, Romeo A. Catalytic effect of sulfoxides on the fluxional motion of 2,9-dimethyl-1,10-phenanthroline in a platinum(II) complex: evaluation of steric and electronic contributions. Inorg Chem 2002; 41:2839-47. [PMID: 12033890 DOI: 10.1021/ic011206j] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Addition of external weak nucleophiles to a chloroform solution of the cationic complex ion [Pt(Me)(dmphen)(PPh(3))](+) (1) accelerates the fluxional motion of the symmetric chelating ligand 2,9-dimethyl-1,10-phenanthroline (dmphen) between nonequivalent exchanging sites. The rates of the dynamic process can be measured by line-shape analysis of the (1)H NMR spectra. Concentration-dependent measurements were carried out with the ligands SOMe(2), SO(CH(2))(4), SO(n-Bu)(2), SO(sec-Bu)(2), SO(i-Pr)(2), SOEt(Ph), SOPr(Ph), SO(Bz)(2), SO(p-MeC(6)H(4))(2), SOPh(2), SO(p-ClC(6)H(4))(2), SOMe(p-MeOC(6)H(4)), SOMe(p-MeC(6)H(4)), SOMe(Ph), SOMe(p-BrC(6)H(4)), and SOMe(p-ClC(6)H(4)). The rate constants k(obsd), when plotted against the concentration of the added ligands SOR(R'), give a family of straight lines with a common intercept, indicating that the two-term rate law k(obsd) = k(1) + k(2)[SOR(R')] is obeyed. The same rate law applies to the displacement of SOMe(2) from [Pt(Me)(phen)(SOMe(2))](+) (2) (phen = 1,10-phenanthroline) by sulfoxides (SOMe(2), SO(i-Pr)(2), SOMe(p-MeOC(6)H(4)), SO(p-MeC(6)H(4))(2), SOPh(2), SO(p-ClC(6)H(4))(2), and SO(sec-Bu)(2)). The fluxional rates in 1 are 6-7 orders of magnitude higher than the substitution rates in 2. The values of the rate constants for the two processes were resolved quantitatively into steric and electronic contributions by use of quantitative analysis of ligand effects (QALE). Inhibitory steric effects are linearly operative for the entire set of ligands, the rates of the reactions are enhanced with increasing electron donor capacity of the sulfoxides, and there is a small but significant E(ar) effect that enhances the reactivity of the aryl sulfoxides. The strict similarity of the patterns of the two processes and of their dependence upon the stereoelectronic properties of the ligands, combined with the intrinsic lability of the platinum-nitrogen bonds, would suggest the operation of stereospecific consecutive ring-opening and ring-closure steps for the fluxional motion of dmphen in 1. However, the available evidence does not allow alternative mechanisms involving intramolecular rearrangements of the five-coordinate intermediate to be ruled out.
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Affiliation(s)
- Raffaello Romeo
- Dipartimento di Chimica Inorganica, Chimica Analitica e Chimica Fisica and ISMN, CNR, Sezione di Messina, Università di Messina, Salita Sperone 31, Villaggio S. Agata, 98166 Messina, Italy.
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Woska D, Prock A, Giering WP. Determination of the Stereoelectronic Parameters of PF3, PCl3, PH3, and P(CH2CH2CN)3. The Quantitative Analysis of Ligand Effects (QALE). Organometallics 2000. [DOI: 10.1021/om0004850] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- David Woska
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Alfred Prock
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Warren P. Giering
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
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Blum O, Carmielli R, Martin JML, Milstein D. Why Does the Tetrakis(trimethylphosphine)iridium(III) Hydridochloride Cation Adopt the Sterically and Electronically Unfavorable Cis Geometry? Organometallics 2000. [DOI: 10.1021/om0004848] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Ofer Blum
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Ra'anan Carmielli
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - Jan M. L. Martin
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
| | - David Milstein
- Department of Organic Chemistry, The Weizmann Institute of Science, Rehovot 76100, Israel
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Fernandez AL, Lee TY, Reyes C, Prock A, Giering WP. A Thermodynamically Based and Definitive Demonstration of the Inadequacy of the ECW Model for Phosphorus(III) Ligands. Organometallics 1998. [DOI: 10.1021/om980262y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anthony L. Fernandez
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Tsung Ying Lee
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Clementina Reyes
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Alfred Prock
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Warren P. Giering
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
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Fernandez A, Reyes C, Prock A, Giering WP. Exploring Ligand Effects through Isoequilibrium Phenomena: The Quantitative Analysis of Ligand Effects. Organometallics 1998. [DOI: 10.1021/om971041f] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anthony Fernandez
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Clementina Reyes
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Alfred Prock
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Warren P. Giering
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
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Slone CS, Mirkin CA, Yap GPA, Guzei IA, Rheingold AL. Oxidation-State-Dependent Reactivity and Catalytic Properties of a Rh(I) Complex Formed from a Redox-Switchable Hemilabile Ligand. J Am Chem Soc 1997. [DOI: 10.1021/ja9723601] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Caroline S. Slone
- Contribution from the Department of Chemistry, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Chad A. Mirkin
- Contribution from the Department of Chemistry, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Glenn P. A. Yap
- Contribution from the Department of Chemistry, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Ilia A. Guzei
- Contribution from the Department of Chemistry, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
| | - Arnold L. Rheingold
- Contribution from the Department of Chemistry, 2145 Sheridan Road, Northwestern University, Evanston, Illinois 60208, and Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware 19716
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Romeo R, Plutino MR, Scolaro LM, Stoccoro S. Reactivity of tertiary phosphines toward a cyclometallated platinum(II) complex: evaluation of steric and electronic contributions. Inorganica Chim Acta 1997. [DOI: 10.1016/s0020-1693(97)05713-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Fernandez A, Reyes C, Wilson MR, Woska DC, Prock A, Giering WP. Examination of Drago's EB and CB Parameters for Phosphines through the Quantitative Analysis of Ligand Effects (QALE). Organometallics 1997. [DOI: 10.1021/om960646t] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Anthony Fernandez
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Clementina Reyes
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Matthew R. Wilson
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - David C. Woska
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Alfred Prock
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
| | - Warren P. Giering
- Department of Chemistry, Metcalf Science and Engineering Center, Boston University, Boston, Massachusetts 02215
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