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Structural Study of Model Rhodium(I) Carbonylation Catalysts Activated by Indole-2-/Indoline-2-Carboxylate Bidentate Ligands and Kinetics of Iodomethane Oxidative Addition. INORGANICS 2022. [DOI: 10.3390/inorganics10120251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The rigid-backbone bidentate ligands Indoline-2-carboxylic acid (IndoliH) and Indole-2-carboxylic acid (IndolH) were evaluated for rhodium(I). IndoliH formed [Rh(Indoli)(CO)(PPh3)] (A2), while IndolH yielded the novel dinuclear [Rh1(Indol’)(CO)(PPh3)Rh2(CO)(PPh3)2] (B2) complex (Indol’ = Indol2−), which were characterized by SCXRD. In B2, the Rh1(I) fragment [Rh1(Indol’)(CO)(PPh3)] (bidentate N,O-Indol) exhibits a square-planar geometry, while Rh2(I) shows a ‘Vaska’-type trans-[O-Rh2(PPh3)2(CO)] configuration (bridging the carboxylate ‘oxo’ O atom of Indol2−). The oxidative addition of MeI to A2 and B2 via time-resolved FT-IR, NMR, and UV/Vis analyses indicated only Rh(III)-alkyl species (A3/B3) as products (no migratory insertion). Variable temperature kinetics confirmed an associative mechanism for A2 via an equilibrium-based pathway (ΔH≠ = (21 ± 1) kJ mol−1; ΔS≠ = (−209 ± 4) J K−1mol−1), with a smaller contribution from a reverse reductive elimination/solvent pathway. The dinuclear complex B2 showed the oxidative addition of MeI only at Rh1(I), which formed a Rh(III)-alkyl, but cleaved the bridged Rh2(I) site, yielding trans-[RhI(PPh3)2(I)(CO)] (5B) as a secondary product. A significantly smaller negative activation entropy [ΔH≠ = (73.0 ± 1.2) kJ mol−1; ΔS≠ = (−21 ± 4) J K−1mol−1] via a more complex/potential interchange mechanism (the contribution of ΔS≠ to the Gibbs free energy of activation, ΔG≠, only ±10%) was inferred, contrary to the entropy-driven oxidative addition of MeI to A2 (the contribution of ΔS≠ to ΔG≠ ± 75%).
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2
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Maseme MR, Buitendach BE, Erasmus E, Swarts JC. The chemistry of spin-coated rhodium-ferrocenyl complexes supported on silanol-capped silicon wafers. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115277] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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3
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Synthesis, characterization, electrochemistry, DFT and kinetic study of the oligothiophene-containing complex [Rh((C4H3S-C4H2S)COCHCOCF3)(CO)(PPh3)]. Polyhedron 2021. [DOI: 10.1016/j.poly.2021.115095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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4
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Conradie MM. Rhodium(triphenylphosphine)carbonyl-2,4-dioxo-3-pentyl-4-decanyloxybenzoate: A DFT study of oxidative addition and methyl migration. Inorganica Chim Acta 2020. [DOI: 10.1016/j.ica.2020.119954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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5
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Babucci M, Guntida A, Gates BC. Atomically Dispersed Metals on Well-Defined Supports including Zeolites and Metal–Organic Frameworks: Structure, Bonding, Reactivity, and Catalysis. Chem Rev 2020; 120:11956-11985. [DOI: 10.1021/acs.chemrev.0c00864] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Melike Babucci
- Department of Chemical Engineering, University of California, Davis, California, 95616, United States
| | - Adisak Guntida
- Department of Chemical Engineering, University of California, Davis, California, 95616, United States
- Center of Excellence on Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Chulalongkorn University, Bangkok 10330, Thailand
| | - Bruce C. Gates
- Department of Chemical Engineering, University of California, Davis, California, 95616, United States
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6
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Buitendach BE, Conradie J, Malan FP, Niemantsverdriet JWH, Swarts JC. Synthesis, Spectroscopy and Electrochemistry in Relation to DFT Computed Energies of Ferrocene- and Ruthenocene-Containing -Diketonato Iridium(III) Heteroleptic Complexes. Structure of [(2-Pyridylphenyl) 2Ir(RcCOCHCOCH 3]. Molecules 2019; 24:E3923. [PMID: 31671705 PMCID: PMC6864483 DOI: 10.3390/molecules24213923] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 10/20/2019] [Accepted: 10/24/2019] [Indexed: 12/02/2022] Open
Abstract
A series of new ferrocene- and ruthenocene-containing iridium(III) heteroleptic complexes of the type [(ppy)2Ir(RCOCHCOR')], with ppy = 2-pyridylphenyl, R = Fc = FeII(η5-C5H4)(η5-C5H5) and R' = CH3 (1) or Fc (2), as well as R = Rc = RuII(η5-C5H4)(η5-C5H5) and R' = CH3 (3), Rc (4) or Fc (5) was synthesized via the reaction of appropriate metallocene-containing β-diketonato ligands with [(ppy)2(-Cl)Ir]2. The single crystal structure of 3 (monoclinic, P21/n, Z = 4) is described. Complexes 1-5 absorb light strongly in the region 280-480 nm the metallocenyl -diketonato substituents quench phosphorescence in 1-5. Cyclic and square wave voltammetric studies in CH2Cl2/[N(nBu)4][B(C6F5)4] allowed observation of a reversible IrIII/IV redox couple as well as well-resolved ferrocenyl (Fc) and ruthenocenyl (Rc) one-electron transfer steps in 1-5. The sequence of redox events is in the order Fc oxidation, then IrIII oxidation and finally ruthenocene oxidation, all in one-electron transfer steps. Generation of IrIV quenched phosphorescence in 6, [(ppy)2Ir(H3CCOCHCOCH3)]. This study made it possible to predict the IrIII/IV formal reduction potential from Gordy scale group electronegativities, χR and/or ΣχR' of -diketonato pendent side groups as well as from DFT-calculated energies of the highest occupied molecular orbital of the species involved in the IrIII/IV oxidation at a 98 % accuracy level.
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Affiliation(s)
| | - Jeanet Conradie
- Department of Chemistry, University of the Free State, Bloemfontein 9300, South Africa.
| | - Frederick P Malan
- Department of Chemistry, University of Pretoria, Pretoria 0002, South Africa.
| | | | - Jannie C Swarts
- Department of Chemistry, University of the Free State, Bloemfontein 9300, South Africa.
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7
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Twigge L, Swarts JC, Conradie J. 103Rh NMR shifts of RhI-β-diketonato and RhI-β-aminoketonato complexes influenced by different substituents. Polyhedron 2019. [DOI: 10.1016/j.poly.2019.04.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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8
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Synthesis of the labile rhenium(I) complexes fac-Re(CO)3(L)[κ2-O,O-FcC(O)CHC(O)Me] (where Fc = ferrocenyl; L = THF, H2O, alkyne) and alkyne addition to the diketonate ligand. J Organomet Chem 2018. [DOI: 10.1016/j.jorganchem.2018.06.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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9
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Warsink S, Riekert Kotze PD, Janse van Rensburg JM(I, Venter JA, Otto S, Botha E, Roodt A. Kinetic‐Mechanistic and Solid‐State Study of the Oxidative Addition and Migratory Insertion of Iodomethane to [Rhodium(
S
,
O
‐
BdiPT
or
N
,
O‐ox
)(CO)(PR
1
R
2
R
3
)] Complexes. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800293] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Stefan Warsink
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
| | - P. D. Riekert Kotze
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
- R&D Division Sasol Technology 1 Klasie Havenga Street 1948 Sasolburg South Africa
| | | | - Johan A. Venter
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
| | - Stefanus Otto
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
- R&D Division Sasol Technology 1 Klasie Havenga Street 1948 Sasolburg South Africa
| | - Ebrahiem Botha
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
| | - Andreas Roodt
- Department of Chemistry University of the Free State PO Box 339 9300 Bloemfontein South Africa
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10
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Buitendach BE, Erasmus E, Niemantsverdriet JW, Swarts JC. Can Electrochemical Measurements Be Used To Predict X-ray Photoelectron Spectroscopic Data? The Case of Ferrocenyl-β-Diketonato Complexes of Manganese(III). Inorg Chem 2018; 57:6606-6616. [PMID: 29762020 DOI: 10.1021/acs.inorgchem.8b00745] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In order to better understand intramolecular communication between molecular fragments, a series of ferrocene-functionalized β-diketonato manganese(III) complexes, [Mn(FcCOCHCOR)3] with R = CF3, 1, CH3, 2, Ph = C6H5, 3, and Fc = FeII(η5-C5H4)(η5-C5H5), 4, the mixed ligand β-diketonato complex [Mn(FcCOCHCOFc)2(FcCOCHCOCH3)], 5, as well as the acac complex [Mn(CH3COCHCOCH3)3], 6, were subjected to an electrochemical and X-ray photoelectron spectroscopy (XPS) study. The ferrocenyl (FeII) and MnIII redox potentials, E°', and photoelectron lines were sufficiently resolved in each complex to demonstrate a linear correlation between E°' and group electronegativities of ligand R groups, χR, or ΣχR, as well as with binding energies of both the Fe 2p3/2 and Mn 2p3/2 photoelectron lines. These relationships are consistent with effective communication between molecular fragments of 1-5. From these relationships, prediction of Mn and Fe core electron binding energies in [Mn(R1COCHCOR2)3] complexes from known manganese and/or ferrocenyl redox potentials are, therefore, now possible. Ligand infrared carbonyl stretching frequencies were successfully related to binding energy as a measure of the energy required for inner-sphere reorganization. In particular it became possible to explain why, upon electrochemical oxidation or photoionization, the ferrocenyl FeII inner-shell of 1-5 needs more energy in complexes with ligands bearing electron-withdrawing (CF3) groups than in ligands bearing electron-donating groups such as ferrocenyl. The XPS determined entity Iratio (the ratio between the intensities of the satellite and main metal 2p3/2 photoelectron lines) is an indication not only of the amount of charge transferred, but also of the degree of inner-sphere reorganization. Just as for binding energy, the quantity Iratio was also found to be related to the energy requirements for the inner-sphere reorganization depicted by the vibrational frequency, vco.
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Affiliation(s)
| | - Elizabeth Erasmus
- Department of Chemistry , University of the Free State , Bloemfontein 9300 , South Africa
| | | | - Jannie C Swarts
- Department of Chemistry , University of the Free State , Bloemfontein 9300 , South Africa
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11
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Stuurman NF, Buitendach BE, Twigge L, Swarts PJ, Conradie J. Rhodium(triphenylphosphine)carbonyl-2,4-dioxo-3-pentyl-4-decanyloxybenzoate: synthesis, electrochemistry and oxidative addition kinetics. NEW J CHEM 2018. [DOI: 10.1039/c7nj05039a] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The influence of a sterically large ligand (CH3COC(C10H21OC6H4COO)COCH3)−, substituted on complex [Rh(CH3COC(C10H21OC6H4COO)COCH3)(CO)(PPh3)], on the ease of rhodium oxidation, is described.
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Affiliation(s)
| | | | - Linette Twigge
- Department of Chemistry
- University of the Free State
- 9300 Bloemfontein
- Republic of South Africa
| | - Pieter J. Swarts
- Department of Chemistry
- University of the Free State
- 9300 Bloemfontein
- Republic of South Africa
| | - Jeanet Conradie
- Department of Chemistry
- University of the Free State
- 9300 Bloemfontein
- Republic of South Africa
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12
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Obuah C, Ainooson MK, Darkwa J. Effects of electrochemical properties of ferrocenylpyrazolylnickel(ii) and palladium(ii) compounds on their catalytic activities in ethylene oligomerisation reactions. RSC Adv 2018; 8:5362-5371. [PMID: 35542429 PMCID: PMC9078115 DOI: 10.1039/c7ra13588b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/24/2018] [Indexed: 11/21/2022] Open
Abstract
Palladium complexes of ferrocenylpyrazolylpyridine and ferrocenylpyrazolylamine were synthesised and screened as pre-catalysts (1–4) for olefin polymerisation. The pre-catalysts 1–4 on activation with EtAlCl2 in the presence of ethylene with chlorobenzene or hexane as solvent were highly active with 1 being the most active, with an activity of 360 kg mol Pd−1 h−1. The major product from the reaction was 1-butene and high carbon content oligomers. The molecular weight (m/z) of the high carbon content oligomers is as high as 623.0. When toluene is used as solvent, the products obtained were ethyltoluene and butyltoluene and 1-butene. The electronic properties of the ligands (L1–L7) and complexes (1–10) were determined by cyclic voltammetry (CV) and molecular modelling. The CV results show that the ferrocenyl is easily oxidized upon the introduction of pyrazolyl derivatives, the process is quasi-reversible. However, complexation of the ligands with palladium or nickel results in difficulty in oxidizing the ferrocenyl moiety. This is an indication of the electrophilic nature of both the palladium and nickel centres. The mechanism of the oxidation was observed to be diffusion-controlled and is independent of scan rate. Molecular modelling experiments show that nickel and palladium complexes have lower HOMO–LUMO gaps and high global descriptors, an indication of a highly electrophilic metal centre. A plot of the electrophilicity indices of the pre-catalysts against yield of the oligomers show a linear correlation, an indication that the electrophilicity of the metal centre plays an important role in the activity of these pre-catalysts. Studying the correlation between the electrophilicity of the metal centre and the activity of the resulting catalyst using electrochemistry and computation modelling.![]()
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Affiliation(s)
- Collins Obuah
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
- Department of Chemistry
| | - Michael K. Ainooson
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
- Department of Chemistry
| | - James Darkwa
- Department of Chemistry
- University of Johannesburg
- Johannesburg
- South Africa
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13
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Misra R, Jadhav T, Nevonen D, Monzo EM, Mobin SM, Nemykin VN. Synthesis, Structures, and Redox Properties of Tetracyano-Bridged Diferrocene Donor–Acceptor–Donor Systems. Organometallics 2017. [DOI: 10.1021/acs.organomet.7b00728] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rajneesh Misra
- Discipline
of Chemistry, Indian Institute of Technology, Indore, 453 552, India
| | - Thaksen Jadhav
- Discipline
of Chemistry, Indian Institute of Technology, Indore, 453 552, India
| | - Dustin Nevonen
- Department
of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
| | - Ellen M. Monzo
- Department of Chemistry & Biochemistry, University of Minnesota Duluth, Duluth, Minnesota 55812, United States
| | - Shaikh M. Mobin
- Discipline
of Chemistry, Indian Institute of Technology, Indore, 453 552, India
| | - Victor N. Nemykin
- Department
of Chemistry, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada
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14
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Spectroscopic monitoring of carbonylation reactions on zeolite supported rhodium(I) carbonyls. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.07.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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15
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Park Y, Ahn S, Kang D, Baik MH. Mechanism of Rh-Catalyzed Oxidative Cyclizations: Closed versus Open Shell Pathways. Acc Chem Res 2016; 49:1263-70. [PMID: 27187270 DOI: 10.1021/acs.accounts.6b00111] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A conceptual theory for analyzing and understanding oxidative addition reactions that form the cornerstone of many transition metal mediated catalytic cycles that activate C-C and C-H bonds, for example, was developed. The cleavage of the σ- or π-bond in the organic substrate can be envisioned to follow a closed or an open shell formalism, which is matched by a corresponding electronic structure at the metal center of the catalyst. Whereas the assignment of one or the other mechanistic scenario appears formal and equivalent at first sight, they should be recognized as different classes of reactions, because they lead to different reaction optimization and control strategies. The closed-shell mechanism involves heterolytic bond cleavages, which give rise to highly localized charges to form at the transition state. In the open-shell pathway, bonds are broken homolytically avoiding localized charges to accumulate on molecular fragments at the transition states. As a result, functional groups with inductive effects may exert a substantial influence on the energies of the intermediate and transition states, whereas no such effect is expected if the mechanism proceeds through the open-shell mechanism. If these functional groups are placed in a way that opens an electronic communication pathway to the molecular sites where charges accumulate, for example, using hyperconjugation, electron donating groups may stabilize a positive charge at that site. An instructive example is discussed, where this stereoelectronic effect allowed for rendering the oxidative addition diastereoselective. No such control is possible, however, when the open-shell reaction pathway is followed, because the inductive effects of functional groups have little to no effect on the stabilities of radical-like substrate states that are encountered when the bonds are broken in a homolytic fashion. Whether the closed-shell or open-shell mechanism for oxidative addition is followed is determined by the ordering of the d-orbital dominated frontier orbitals. If the highest occupied molecular orbital (HOMO) is oriented in space in such a way that will give the organic substrate easy access to the valence electron pair, the closed-shell mechanism can be followed. If the shape and orientation of the HOMO is not appropriate, however, an alternative pathway involving singlet excited states of the metal that will invoke the matching radicaloid cleavage of the organic substrate will dominate the oxidative addition. This novel paradigm for formally analyzing and understanding oxidative additions provides a new way of systematically understanding and planning catalytic reactions, as demonstrated by the in silico design of room-temperature Pauson-Khand reactions.
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Affiliation(s)
- Yoonsu Park
- Center for Catalytic Hydrocarbon
Functionalizations, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Seihwan Ahn
- Center for Catalytic Hydrocarbon
Functionalizations, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Dahye Kang
- Center for Catalytic Hydrocarbon
Functionalizations, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
| | - Mu-Hyun Baik
- Center for Catalytic Hydrocarbon
Functionalizations, Institute for Basic Science (IBS), Daejeon 305-701, Republic of Korea
- Department of Chemistry, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Republic of Korea
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16
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van Rooyen PH, Conradie J. Orientation of trimethylolethane cyclic phosphite in rhodium complexes: Structure of [Rh(CH3COCHCOCH3)(CO)(P(OCH2)3CCH3)]. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.03.032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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17
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Buitendach BE, Erasmus E, Landman M, Niemantsverdriet JWH, Swarts JC. Consequences of Electron-Density Manipulations on the X-ray Photoelectron Spectroscopic Properties of Ferrocenyl-β-diketonato Complexes of Manganese(III). Structure of [Mn(FcCOCHCOCH3)3]. Inorg Chem 2016; 55:1992-2000. [PMID: 26886078 DOI: 10.1021/acs.inorgchem.5b02250] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Reaction of [Mn3(OAc)6O·3H2O](+) (1) with ferrocenyl β-diketones of the type FcCOCH2COR with R = CF3 (2a) and CH3 (2b), Ph = C6H5 (2c), and Fc = Fe(II)(η(5)-C5H4)(η(5)-C5H5) (2d) yielded a series of ferrocene-functionalized β-diketonato manganese(III) complexes 3a-3d, respectively, of general formula [Mn(FcCOCHCOR)3]. The mixed-ligand β-diketonato complex [Mn(FcCOCHCOFc)2(FcCOCHCOCH3)] (4) was obtained by reacting mixtures of diketones 2b and 2d with 1. A single-crystal X-ray structure determination of 3b (Z = 2, triclinic, space group P1̅) highlighted a weak axial elongating Jahn-Teller effect and a high degree of bond conjugation. An X-ray photoelectron spectroscopic study, by virtue of linear relationships between group electronegativities of ligand R groups, χR, or ∑χR, and binding energies of both the Fe 2p3/2 and Mn 2p3/2 photoelectron lines, confirmed communication between molecular fragments of 2a-2d as well as 3a-3d. This unprecedented observation allows prediction of binding energies from known β-diketonato side group χR values.
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Affiliation(s)
| | - Elizabeth Erasmus
- Department of Chemistry, University of the Free State , Bloemfontein 9300, South Africa
| | - Marilé Landman
- Department of Chemistry, University of Pretoria , Pretoria, South Africa
| | - J W Hans Niemantsverdriet
- Syngaschem BV, Helix Building, Campus of the Eindhoven University of Technology , Eindhoven, The Netherlands
| | - Jannie C Swarts
- Department of Chemistry, University of the Free State , Bloemfontein 9300, South Africa
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18
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Erasmus E. Synthesis and electrochemistry of p-substituted phenyl diphenylphosphinite rhodium(I) complexes. Polyhedron 2016. [DOI: 10.1016/j.poly.2015.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Purcell W, Conradie J, Kumar S, Venter JA. Characterisation and mechanistic study of the oxidative addition reactions of [Ir(cod)(sacac)]. J Organomet Chem 2016. [DOI: 10.1016/j.jorganchem.2015.10.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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Robbins LK, Lilly CP, Smeltz JL, Boyle PD, Ison EA. Synthesis and Reactivity of Oxorhenium(V) Methyl, Benzyl, and Phenyl Complexes with CO: Implications for a Unique Mechanism for Migratory Insertion. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00177] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Leanna K. Robbins
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Cassandra P. Lilly
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Jessica L. Smeltz
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Paul D. Boyle
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
| | - Elon A. Ison
- Department
of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
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21
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Conradie J. Density functional theory calculations of Rh-β-diketonato complexes. Dalton Trans 2015; 44:1503-15. [PMID: 25429658 DOI: 10.1039/c4dt02268h] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory results on the geometry, energies and charges of selected Rh-β-diketonato reactants, products and transition states.
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Affiliation(s)
- J. Conradie
- Department of Chemistry
- University of the Free State
- 9300 Bloemfontein
- Republic of South Africa
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22
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Bezuidenhout DI, van der Westhuizen B, Strydom I, Swarts PJ, Swarts JC, Fernández I. Synthesis and electrochemical investigation of chromium(0) ferrocenyl-substituted carbene complexes. Inorganica Chim Acta 2014. [DOI: 10.1016/j.ica.2014.07.068] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Erasmus E. Synthesis and unexpected electrochemical reaction of p-substituted phenyl diphenylphosphinites. J Electroanal Chem (Lausanne) 2014. [DOI: 10.1016/j.jelechem.2014.05.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Fourie E, van Rensburg JMJ, Swarts JC. Synthesis, crystal structure and comparative electrochemistry of metallocenyldiphenylphosphines of ruthenocene, osmocene, ferrocene and cobaltocenium hexafluorophosphate. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2013.12.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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25
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Bezuidenhout DI, Fernández I, van der Westhuizen B, Swarts PJ, Swarts JC. Electrochemical and Computational Study of Tungsten(0) Ferrocene Complexes: Observation of the Mono-Oxidized Tungsten(0) Ferrocenium Species and Intramolecular Electronic Interactions. Organometallics 2013. [DOI: 10.1021/om400865m] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Daniela I. Bezuidenhout
- Department of Chemistry, University of Pretoria, Private Bag
X20, Hatfield 0028, Pretoria, South Africa
| | - Israel Fernández
- Departamento de Quı́mica Orgánica
I, Facultad de Ciencias Quı́micas, Universidad Complutense, 28040 Madrid, Spain
| | | | - Pieter J. Swarts
- Chemistry Department, University of the Free State, P.O. Box
339, Bloemfontein 9300, South Africa
| | - Jannie C. Swarts
- Chemistry Department, University of the Free State, P.O. Box
339, Bloemfontein 9300, South Africa
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Characterization and oxidative addition reactions of rhodium(I) carbonyl cupferrate diphenyl-2-pyridylphoshine complexes. J Organomet Chem 2013. [DOI: 10.1016/j.jorganchem.2013.08.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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28
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Structural influences on the electrochemistry of 1,1′-di(hydroxyalkyl)ferrocenes. Structure of [Fe{η5-C5H4–CH(OH)–(CH2)3OH}2]. J Organomet Chem 2013. [DOI: 10.1016/j.jorganchem.2013.05.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Buitendach BE, Gągor A, Swarts JC. Electrochemical evidence of intramolecular electronic communication in Zr and Hf phthalocyanines bearing ferrocene-containing β-diketonato axial ligands: structure of [PcHf(FcCOCHCOC6H5)2]. Inorg Chem 2013; 52:10245-57. [PMID: 23971994 DOI: 10.1021/ic302730v] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The series of zirconium(IV) and hafnium(IV) phthalocyanine complexes [PcM(FcCOCHCOR)2] (Pc = phthalocyaninato; M = Zr; R = CF3 (1), CH3 (2), C6H5 (3), Fc ((C5H5)Fe(C5H4), 4), as well as M = Hf ; R = CF3 (5), CH3 (6), C6H5 (7), and Fc (8)) were synthesized. A single-crystal X-ray diffraction analysis of the structure of [PcHf(FcCOCHCOC6H5)2], 7 (Z = 2, space group P1), showed the two axial β-diketonato ligands were orientated in such a way that the ferrocenyl groups were positioned diagonally opposite each other. From the structural determination of 7 it was clear that these complexes have a distorted D4h symmetry at the coordination site of the metal centers, which explains a splitting of the UV-vis Q band into Qx and Qy components with 3 ≤ Δλ(max,Q) ≤ 10 nm. Cyclic and square wave voltammetric studies in CH2Cl2/[N((n)Bu)4][B(C6F5)4] allowed observation of at least three phthalocyaninato macrocycle-based redox couples as well as all (i.e., two or four) well-resolved ferrocenyl couples in 1-8. For M = Zr and R = Fc, formal reduction potentials of the four ferrocenyl groups were found to be E°' = 296, 386, 538, and 687 mV versus free ferrocene. Spectroelectrochemical evidence, UV-vis Q-band maximum wavelengths, and HOMO-LUMO energy gaps as expressed by ΔE°'I-III = ΔE°'wave I - ΔE°'wave III were mutually consistent, indicating that the first phthalocyaninato ring-based oxidation occurs before ferrocenyl oxidations take place. The potential for each redox process was found to be dependent on the sum of β-diketonato R-group group electronegativities, ΣχR. Mathematical relationships for the dependency of E°' on ΣχR for all four observed ring-based redox processes as well as for the ferrocenyl-based redox processes were determined. This allowed prediction of potentials for redox processes that fall outside the workable potential window of the solvent. No significant differences were found between the corresponding redox potentials of zirconium and hafnium analogues bearing the same axial ligands.
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Affiliation(s)
- Blenerhassitt E Buitendach
- Department of Chemistry, University of the Free State , P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
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Taher D, Awwadi FF, Pfaff U, Speck JM, Rüffer T, Lang H. A series of Se-ferrocenyl thiophene carboselenoates – Synthesis, solid-state structure and electrochemistry. J Organomet Chem 2013. [DOI: 10.1016/j.jorganchem.2013.02.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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31
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van der Westhuizen B, Swarts PJ, van Jaarsveld LM, Liles DC, Siegert U, Swarts JC, Fernández I, Bezuidenhout DI. Substituent Effects on the Electrochemical, Spectroscopic, and Structural Properties of Fischer Mono- and Biscarbene Complexes of Chromium(0). Inorg Chem 2013; 52:6674-84. [DOI: 10.1021/ic4007422] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
| | - Pieter J. Swarts
- Chemistry Department, University of the Free State, P.O. Box 339, Bloemfontein
9300, South Africa
| | - Louise M. van Jaarsveld
- Chemistry Department, University of Pretoria, Private Bag X20, Hatfield 0028,
Pretoria, South Africa
| | - David C. Liles
- Chemistry Department, University of Pretoria, Private Bag X20, Hatfield 0028,
Pretoria, South Africa
| | - Uwe Siegert
- Chemistry Department, University of the Free State, P.O. Box 339, Bloemfontein
9300, South Africa
| | - Jannie C. Swarts
- Chemistry Department, University of the Free State, P.O. Box 339, Bloemfontein
9300, South Africa
| | - Israel Fernández
- Departamento
de Química
Orgánica I, Facultad de Química, Universidad Complutense, 28040 Madrid, Spain
| | - Daniela I. Bezuidenhout
- Chemistry Department, University of Pretoria, Private Bag X20, Hatfield 0028,
Pretoria, South Africa
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Joubert CC, van As L, Jakob A, Speck JM, Lang H, Swarts JC. Intramolecular electronic communication in ferrocene-based β-diketonato copper(II) complexes as observed by an electrochemical study. Polyhedron 2013. [DOI: 10.1016/j.poly.2013.02.059] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Characterization of acetylacetonato carbonyl diphenyl-2-pyridylphosphine rhodium(I): Comparison with other carbonyl complexes. J Mol Struct 2013. [DOI: 10.1016/j.molstruc.2013.01.061] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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34
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Stuurman NF, Muller A, Conradie J. Structural trends in [Rh(PhCOCHCO(CH2)nCH3)(CO)(PPh3)] (n = 0–3) and related complexes: crystal structure of [Rh(PhCOCHCO(CH2)2CH3)(CO)(PPh3)]. TRANSIT METAL CHEM 2013. [DOI: 10.1007/s11243-013-9708-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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35
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Synthesis and electrochemical properties of ferrocene-containing N-allylcarbamates: Structure of CH2CHCH2–NHCOO–CH2Fc. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.12.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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36
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Conradie J. A DFT study of the reactivity of β-diketonato-1,5-cyclo-octadieneiridium(I) complexes. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.12.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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37
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Synthesis and characterization of rhodium(I) 2-methylcupferrate complexes and their kinetic behaviour in iodomethane oxidative addition. J Organomet Chem 2013. [DOI: 10.1016/j.jorganchem.2012.12.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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38
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Erasmus JJC, Conradie J. Chemical and electrochemical oxidation of [Rh(β-diketonato)(CO)(P(OCH2)3CCH3)]: an experimental and DFT study. Dalton Trans 2013; 42:8655-66. [DOI: 10.1039/c3dt50310k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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39
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van der Westhuizen B, Swarts PJ, Strydom I, Liles DC, Fernández I, Swarts JC, Bezuidenhout DI. Electrochemical illumination of thienyl and ferrocenyl chromium(0) Fischer carbene complexes. Dalton Trans 2013; 42:5367-78. [DOI: 10.1039/c3dt32913e] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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40
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Stuurman NF, Muller A, Conradie J. Conformational analysis of triphenylphosphine in square planar [Rh(β-diketonato)(CO)(PPh3)] complexes. Crystal structure of [Rh(PhCOCHCO(CH2)3CH3)(CO)(PPh3)]. Inorganica Chim Acta 2013. [DOI: 10.1016/j.ica.2012.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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41
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Erasmus E, Swarts JC. Intramolecular communication and electrochemical observation of the 17-electron ruthenocenium cation in fluorinated ruthenocene-containing β-diketones; polymorphism of C10H21 and C10F21 derivatives. NEW J CHEM 2013. [DOI: 10.1039/c3nj00354j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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42
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Nguyen DH, Modrego FJ, Cetina-Casas JM, Gómez-Bautista D, Jiménez MV, Castarlenas R, Lahoz FJ, Oro LA, Pérez-Torrente JJ. Steric Effects in the Oxidative Addition of MeI to a Sulfido-Bridged ZrRh2 Early–Late Heterobimetallic Compound. Organometallics 2012. [DOI: 10.1021/om300629k] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Affiliation(s)
- Duc Hanh Nguyen
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - F. Javier Modrego
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - J. Miguel Cetina-Casas
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - Daniel Gómez-Bautista
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - M. Victoria Jiménez
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - Ricardo Castarlenas
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - Fernando J. Lahoz
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - Luis A. Oro
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
| | - Jesús J. Pérez-Torrente
- Departamento de
Quı́mica Inorgánica, Instituto de
Sı́ntesis Quı́mica y Catálisis Homogénea-ISQCH, Universidad de Zaragoza-CSIC, C/Pedro Cerbuna 12, 50009-Zaragoza,
Spain
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43
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Speck JM, Claus R, Hildebrandt A, Rüffer T, Erasmus E, van As L, Swarts JC, Lang H. Electron Transfer Studies on Ferrocenylthiophenes: Synthesis, Properties, and Electrochemistry. Organometallics 2012. [DOI: 10.1021/om3006036] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- J. Matthäus Speck
- Fakultät für Naturwissenschaften,
Institut für Chemie, Lehrstuhl
für Anorganische Chemie, Technische Universität Chemnitz, Straße der Nationen
62, 09111 Chemnitz, Germany
| | - Ron Claus
- Fakultät für Naturwissenschaften,
Institut für Chemie, Lehrstuhl
für Anorganische Chemie, Technische Universität Chemnitz, Straße der Nationen
62, 09111 Chemnitz, Germany
| | - Alexander Hildebrandt
- Fakultät für Naturwissenschaften,
Institut für Chemie, Lehrstuhl
für Anorganische Chemie, Technische Universität Chemnitz, Straße der Nationen
62, 09111 Chemnitz, Germany
| | - Tobias Rüffer
- Fakultät für Naturwissenschaften,
Institut für Chemie, Lehrstuhl
für Anorganische Chemie, Technische Universität Chemnitz, Straße der Nationen
62, 09111 Chemnitz, Germany
| | - Elizabeth Erasmus
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein,
South Africa
| | - Lydia van As
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein,
South Africa
| | - Jannie C. Swarts
- Department of Chemistry, University of the Free State, PO Box 339, Bloemfontein,
South Africa
| | - Heinrich Lang
- Fakultät für Naturwissenschaften,
Institut für Chemie, Lehrstuhl
für Anorganische Chemie, Technische Universität Chemnitz, Straße der Nationen
62, 09111 Chemnitz, Germany
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Oxidative addition of methyl iodide to [Rh(PhCOCHCOPh)(CO)(P(OCH2)3CCH3)]: an experimental and computational study. OPEN CHEM 2012. [DOI: 10.2478/s11532-011-0137-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractThe reaction rate of the oxidative addition and CO insertion steps of methyl iodide with [Rh(PhCOCHCOPh)(CO)(P(OCH2)3CCH3)] are presented. Large negative experimental values for the activation entropy and results from a density functional theory computational chemistry study indicated trans addition of the CH3I to [Rh(PhCOCHCOPh)(CO)(P(OCH2)3CCH3)]. A study of the molecular orbitals gives insight into the flow of electrons during the oxidative addition reaction. CO insertion leads to a square pyramidal [Rh(PhCOCHCOPh)(P(OCH2)3CCH3)(COCH3)(I)] acyl product with the COCH3 moiety in the apical position. The strong electron donation of the P(OCH2)3CCH3 ligand accelerates the oxidation addition step of methyl iodide to [Rh(PhCOCHCOPh)(CO)(P(OCH2)3CCH3)] by ca. 265 times faster (at 35°C) than that of the Monsanto catalyst, but inhibits the CO insertion step.
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Gericke HJ, Muller AJ, Swarts JC. Electrochemical illumination of intramolecular communication in ferrocene-containing tris-β-diketonato aluminum(III) complexes; cytotoxicity of Al(FcCOCHCOCF3)3. Inorg Chem 2012; 51:1552-61. [PMID: 22272584 DOI: 10.1021/ic201849u] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The series of ferrocene-containing tris-β-diketonato aluminum(III) complexes [Al(FcCOCHCOR)(3)] (R = CF(3), 1; CH(3), 2; C(6)H(5), 3; and Fc = ferrocenyl = Fe(η(5)-C(5)H(5))(η(5)-C(5)H(4)), 4) were synthesized and investigated structurally and electrochemically; complex 1 was subjected to cytotoxicity tests. (1)H NMR-spectroscopy distinguished between the mer and fac isomers of 2 and 3. Complex 1 existed only as the mer isomer. A single crystal X-ray crystallographic determination of the structure of a mer-isomer of Al(FcCOCHCOCF(3))(3), 1, (Z = 4, space group P2(1)2(1)2(1)) demonstrated extensive delocalization of all bonds which explained the pronounced electrochemically observed intramolecular communication between molecular fragments. In contrast to electrochemical studies in CH(2)Cl(2)/[N((n)Bu)(4)][PF(6)], the use of the supporting electrolyte [N((n)Bu)(4)][B(C(6)F(5))(4)] allowed identification of all Fc/Fc(+) electrochemical couples by cyclic and square wave voltammetry for 1-4. For R = Fc, formal reduction potentials of the six ferrocenyl groups were found to be E°' = 33, 123, 304, 432, 583, and 741 mV versus free ferrocene respectively. Complex 1 (IC(50) = 10.6 μmol dm(-3)) was less cytotoxic than the free FcCOCH(2)COCF(3) ligand having IC(50) = 6.8 μmol dm(-3) and approximately 2 orders of magnitude less toxic to human HeLa neoplastic cells than cisplatin (IC(50) = 0.19 μmol dm(-3)).
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Affiliation(s)
- Henno J Gericke
- Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein, 9300, Republic of South Africa
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46
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Conradie J. Conformational analysis of triphenylphosphine in square planar organometallic complexes: [(PPh3)(ML1L2L3)] and [M(acac)(L′)(PPh3)]. Dalton Trans 2012; 41:10633-42. [DOI: 10.1039/c2dt30850a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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47
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Erasmus JJC, Conradie MM, Conradie J. Kinetics and mechanism of the oxidative addition of methyl iodide to [Rh(CH3COCHCOCF3)(CO)(P(OCH2)3CCH3)]: an experimental and computational study. REACTION KINETICS MECHANISMS AND CATALYSIS 2011. [DOI: 10.1007/s11144-011-0413-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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48
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Ferrocene- and ruthenocene-containing chalcones: A spectroscopic and electrochemical study. Inorganica Chim Acta 2011. [DOI: 10.1016/j.ica.2011.08.024] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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49
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Trifluoroacetylacetonate rhodium(III) methyl complexes, cis-[Rh(TFA)(PPh3)2(CH3)(L)][BPh4] and cis-[Rh(TFA)(PPh3)2(CH3)(I)] (L=CH3CN, NH3, pyridine), in comparison with their acetylacetonate analogs. J Organomet Chem 2011. [DOI: 10.1016/j.jorganchem.2011.06.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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50
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Erasmus JJ, Conradie J. Electrochemical study of β-diketonatobis(triphenylphosphite)rhodium(I) complexes. Electrochim Acta 2011. [DOI: 10.1016/j.electacta.2011.08.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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