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Hong D, Zhu X, Wang S, Wei Y, Zhou S, Huang Z, Zhu S, Wang R, Yue W, Mu X. Synthesis, characterization, and reactivity of dinuclear organo-rare-earth-metal alkyl complexes supported by 2-amidate-functionalized indolyl ligands: substituent effects on coordination and reactivity. Dalton Trans 2019; 48:5230-5242. [PMID: 30899927 DOI: 10.1039/c9dt00507b] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Two series of new dinuclear organo-rare-earth-metal alkyl complexes supported by 2-amidate-functionalized indolyl ligands with different haptic modes were synthesized and characterized. The treatment of [RE(CH2SiMe3)3(THF)2] with 1 equiv. of 2-(2,6-iPr2C6H3NHC[double bond, length as m-dash]O)C8H5NH (H2L1) and 2-(2-tBuC6H4NHC[double bond, length as m-dash]O)C8H5NH (H2L2) in toluene yielded the dinuclear organo-rare-earth-metal alkyl complexes {[η1:(μ2-η1:η1)-L1]RE(CH2SiMe3)(THF)2}2 [RE = Gd (1a), Dy (1b), Y (1c), Er (1d), and Yb (1e)] and {[η1:(μ2-η1:η1):η1-L2]RE(CH2SiMe3)(THF)2}2 [RE = Gd (2a), Dy (2b), Y (2c), Er (2d), and Yb (2e)] in good yields. When [RE(CH2SiMe3)3(THF)2] were treated with 2 equiv. of H2L1 or H2L2 in THF, the dinuclear organo-rare-earth-metal complexes {(η1:η1-HL)[η1:(μ2-η1:η1):η1-L]RE(THF)}2 (1ca: RE = Y, L = L1; 2ea: RE = Yb, L = L2) were obtained. The complexes could react with small organic molecules such as N,N'-diisopropylcarbodiimide (DIC), phenyl isocyanate, N-methylallylamine, phenylacetylene, pyridine, N-phenylimidazole, or 4-dimethylaminopyridine (DMAP) to yield a series of new complexes with different reactivity patterns along with the reported rare-earth-metal alkyl complexes. In the presence of cocatalysts, these dinuclear organo-rare-earth-metal alkyl complexes could initiate isoprene polymerization with high activity (100% conversion of 2000 equiv. of isoprene in 12 h), yielding polymers with high regioselectivity (1,4 polymers up to 96.1%).
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Affiliation(s)
- Dongjing Hong
- Laboratory of Functional Molecular Solids, Ministry of Education, Anhui Laboratory of Molecule-Based Materials, College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241002, P. R. China.
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Duncan Lyngdoh RH, Schaefer HF, King RB. Metal-Metal (MM) Bond Distances and Bond Orders in Binuclear Metal Complexes of the First Row Transition Metals Titanium Through Zinc. Chem Rev 2018; 118:11626-11706. [PMID: 30543419 DOI: 10.1021/acs.chemrev.8b00297] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
This survey of metal-metal (MM) bond distances in binuclear complexes of the first row 3d-block elements reviews experimental and computational research on a wide range of such systems. The metals surveyed are titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, and zinc, representing the only comprehensive presentation of such results to date. Factors impacting MM bond lengths that are discussed here include (a) the formal MM bond order, (b) size of the metal ion present in the bimetallic core (M2) n+, (c) the metal oxidation state, (d) effects of ligand basicity, coordination mode and number, and (e) steric effects of bulky ligands. Correlations between experimental and computational findings are examined wherever possible, often yielding good agreement for MM bond lengths. The formal bond order provides a key basis for assessing experimental and computationally derived MM bond lengths. The effects of change in the metal upon MM bond length ranges in binuclear complexes suggest trends for single, double, triple, and quadruple MM bonds which are related to the available information on metal atomic radii. It emerges that while specific factors for a limited range of complexes are found to have their expected impact in many cases, the assessment of the net effect of these factors is challenging. The combination of experimental and computational results leads us to propose for the first time the ranges and "best" estimates for MM bond distances of all types (Ti-Ti through Zn-Zn, single through quintuple).
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Affiliation(s)
| | - Henry F Schaefer
- Centre for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 , United States
| | - R Bruce King
- Centre for Computational Quantum Chemistry , University of Georgia , Athens , Georgia 30602 , United States
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Dolinar BS, Berry JF. Electronic tuning of Mo2(thioamidate)4 complexes through π-system substituents and cis/trans isomerism. Dalton Trans 2014; 43:6165-76. [PMID: 24590395 DOI: 10.1039/c4dt00297k] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We report an exploration of the coordination chemistry of a systematic series of cyclic thioamidate ligands with the quadruply-bonded Mo2(4+) core. In addition to the S and N donor atoms that bind to Mo, the ligands utilized in this study have an additional O or S atom in conjugation with the thioamidate π system. The preparation of four new Mo2 complexes is described, and these compounds are characterized by X-ray crystallography, NMR and UV-vis spectroscopy, electrochemistry, and DFT calculations. These complexes provide a means to interrogate the electronics of Mo2(thioamidate)4 systems. Notably, we describe the first two examples of Mo2(thioamidate)4 complexes in their cis-2,2-regioisomer. By varying the π-system substituent and regioisomerism of these compounds, the electronics of the dimolybdenum core is shown to be altered with varying degrees of effect. Cyclic voltammetry results show that changing the π-system substituent from O to S results in an increase in the Mo2(4+/5+) oxidation potential by 170 mV. Changing the arrangement of ligands around the dimolybdenum core from trans-2,2 to cis-2,2 slightly weakens the metal-ligand bonds, raising the oxidation potential by a more modest 30-100 mV. MO diagrams of each compound derived from DFT calculations support these conclusions as well; the identity of the π-system substituent alters the δ-δ* (HOMO-LUMO) gap by up to 0.4 eV, whereas regioisomerism yields smaller changes in the electronic structure.
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Affiliation(s)
- Brian S Dolinar
- Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53704, USA.
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Da Re RE, Eglin JL, Carlson CN, John KD, Morris DE, Woodruff WH, Bailey JA, Batista E, Martin RL, Cotton FA, Hillard EA, Murillo CA, Sattelberger AP, Donohoe RJ. Nature of bonding in complexes containing "supershort" metal-metal bonds. raman and theoretical study of M2(dmp)4 [M = Cr (natural abundance Cr, 50Cr, and 54Cr) and Mo; dmp = 2,6-dimethoxyphenyl]. J Am Chem Soc 2010; 132:1839-47. [PMID: 20092271 PMCID: PMC2837474 DOI: 10.1021/ja9055504] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
We report an investigation of complexes of the type M(2)(dmp)(4) (M = Mo, Cr; dmp = 2,6-dimethoxyphenyl) using resonance Raman (RR) spectroscopy, Cr isotopic substitution, and density functional theory (DFT) calculations. Assignment of the Mo-Mo stretching vibration in the Mo(2) species is straightforward, as evidenced by a single resonance-enhanced band at 424 cm(-1), consistent with an essentially unmixed metal-metal stretch, and overtones of this vibration. On the other hand, the Cr(2) congener has no obvious metal-metal stretching mode near 650-700 cm(-1), where empirical predictions based on the Cr-Cr distance as well as DFT calculations suggest that this vibration should appear if unmixed. Instead, three bands are observed at 345, 363, and 387 cm(-1) that (a) have relative RR intensities that are sensitive to the Raman excitation frequency, (b) exhibit overtones and combinations in the RR spectra, and (c) shift in frequency upon isotopic substitution ((50)Cr and (54)Cr). DFT calculations are used to model the vibrational data for the Mo(2) and Cr(2) systems. Both the DFT results and empirical predictions are in good agreement with experimental observations in the Mo(2) complex, but both, while mutually consistent, differ radically from experiment in the Cr(2) complex. Our experimental and theoretical results, especially the Cr isotope shifts, clearly demonstrate that the potential energy of the Cr-Cr stretching coordinate is distributed among several normal modes having both Cr-Cr and Cr-ligand character. The general significance of these results in interpreting spectroscopic observations in terms of the nature of metal-metal multiple bonding is discussed.
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Affiliation(s)
- Ryan E. Da Re
- ITT Corporation, Advanced Engineering and Sciences, 2560 Huntington Avenue, Alexandria VA 22303-1404
| | - Judith L. Eglin
- Chemistry, Los Alamos National Laboratory, Los Alamos, NM 87545
| | | | - Kevin D. John
- Chemistry, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - David E. Morris
- Materials Physics and Applications, Los Alamos National Laboratory, Los Alamos, NM 87545
| | | | - James A. Bailey
- Chemistry, Earth & Environmental Sciences, Irving K. Barber School of Arts and Sciences, UBC Okanagan, 3333 University Way, Kelowna, BC Canada V1V 1V7
| | - Enrique Batista
- Theory Divisions, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - Richard L. Martin
- Theory Divisions, Los Alamos National Laboratory, Los Alamos, NM 87545
| | - F. Albert Cotton
- Department of Chemistry, Laboratory for Molecular Structure and Bonding, P.O. Box 30012, Texas A&M University, College Station, TX 77842-3012
| | - Elizabeth A. Hillard
- Laboratoire de Chimie et Biochimie des Complexes Moleculaires, Ecole Nationale Superieure de Chimie de Paris, UMR CNRS 7576, 11, rue Pierre et Marie Curie, 75231 Paris Cedex 05, France
| | - Carlos A. Murillo
- Department of Chemistry, Laboratory for Molecular Structure and Bonding, P.O. Box 30012, Texas A&M University, College Station, TX 77842-3012
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Lee AV, Schafer LL. Modular
N
,
O
‐Chelating Ligands: Group‐4 Amidate Complexes for Catalytic Hydroamination. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700036] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Alison V. Lee
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Laurel L. Schafer
- Department of Chemistry, The University of British Columbia, Vancouver, British Columbia, Canada
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Cuevas JV, Garcı́a-Herbosa G, Miguel D, Muñoz A. The first structurally characterized acetanilidocomplex of palladium (II) and the maximum hardness principle. A sample of trans choice in square-planar complexes. INORG CHEM COMMUN 2002. [DOI: 10.1016/s1387-7003(02)00395-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Cotton FA, Daniels LM, Donahue JP, Liu CY, Murillo CA. The first designed syntheses of bis-dimetal molecules in which the bridges are diamidate ligands. Inorg Chem 2002; 41:1354-6. [PMID: 11896701 DOI: 10.1021/ic025503f] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The first deliberate syntheses of molecules in which pairs of quadruply bonded Mo2 units are bridged by N,N'-diarylterephthaloyldiamidate (aryl = Ph, m-CF3Ph) ligands are described. The addition of neutral N,N'-diarylterephthaloyldiamide to 2 equiv of [Mo2(DAniF)3(MeCN)2]+ (DAniF = N,N'-di-p-anisylformamidinate) followed by the introduction of excess H3CO- in MeCN results in the formation of (DAniF)3Mo2[(C6H5)NC(O)C6H4(O)CN(C6H5)]Mo2(DAniF)3 (1) and (DAniF)3Mo2[[(m-CF3)C6H5]NC(O)C6H4(O)CN[(m-CF3)C6H5]]Mo2(DAniF)3 (2). The DeltaE1/2 for the oxidation of each Mo2 unit is greater for these terephthaloyldiamidate-bridged molecules (approximately 100 mV) than for the analogous terephthalate-bridged compound (approximately 60 mV). Variation in the nature of the substituents on the diamidate nitrogen atoms offers a means to fine-tune the oxidation potentials of the Mo2 units.
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Affiliation(s)
- F Albert Cotton
- Department of Chemistry and Laboratory for Molecular Structure and Bonding, P.O. Box 30012, Texas A&M University, College Station, Texas 77842-3012, USA.
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Boeyens JCA, O'Neill FMM. Molecular Modeling of Dimetal Systems. Part 3. Dichromium Bonds. Inorg Chem 1998. [DOI: 10.1021/ic960268k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jan C. A. Boeyens
- Centre for Molecular Design, Department of Chemistry, University of the Witwatersrand, P.O. Wits, 2050 Johannesburg, South Africa
| | - Francoise M. M. O'Neill
- Centre for Molecular Design, Department of Chemistry, University of the Witwatersrand, P.O. Wits, 2050 Johannesburg, South Africa
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Cotton FA, Lu J, Huang Y. A Novel Tetranuclear Compound: Crystal Structure and Mass Spectra of [Re4(C6H5NCOCH3)6(Cl)(μ-O)(μ-OH)(MeOH)3][ReO4]2. Inorg Chem 1996. [DOI: 10.1021/ic941092u] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- F. Albert Cotton
- Department of Chemistry and Laboratory for Molecular Structure and Bonding, Texas A&M University, College Station, Texas 77843
| | - Jian Lu
- Department of Chemistry and Laboratory for Molecular Structure and Bonding, Texas A&M University, College Station, Texas 77843
| | - Yong Huang
- Department of Chemistry and Laboratory for Molecular Structure and Bonding, Texas A&M University, College Station, Texas 77843
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Cotton F, Lu J, Ren T. Synthesis and crystal structure of amidato-bridged dirhenium(III,III) compounds. Polyhedron 1994. [DOI: 10.1016/s0277-5387(00)81688-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Aqueous redox chemistry of dinuclear clusters. A mechanistic study of proton oxidative addition to the Mo2Cl84− ion and the homogeneous reduction of Mo2(μ-X)(μ-Cl)2 Cl63−, X = H, Cl by aqueous chromium(II). Polyhedron 1987. [DOI: 10.1016/s0277-5387(00)84534-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Pellin MJ, Foosnaes T, Gruen DM. Fluorescence spectrum of Mo2in argon and krypton matrices. J Chem Phys 1981. [DOI: 10.1063/1.440917] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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