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Askari MS, Ottenwaelder X. Oxygen-atom transfer to a nucleophilic molybdenum complex. Dalton Trans 2010; 39:2644-50. [PMID: 20179859 DOI: 10.1039/b921591c] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The reactivity of the imido-Mo(IV) species [(eta(5)-Cp)(2)Mo(N(t)Bu)], 1, towards the iodine-based oxidant PhIO was investigated and yielded the micro-oxodimolybdenum(V) dimer [{(eta(5)-Cp)(eta(1)-Cp)Mo(N(t)Bu)}(2)O], 2. X-Ray crystallography and (1)H-NMR of 2 indicate slipping of one of the eta(5)-Cp ring on each Mo center to eta(1)-Cp as the result of the coordination of the oxygen atom. DFT investigation of the OAT reaction to complex 1 revealed a transient Mo(IV)-oxo species as the most likely intermediate.
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Affiliation(s)
- Mohammad S Askari
- Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke st. West, Montreal, QC H4B 1R6, Canada
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Moghadam M, Mirkhani V, Tangestaninejad S, Mohammadpoor-Baltork I, Javadi MM. Polyoxometalate–molybdenylacetylacetonate hybrid complex: A reusable and efficient catalyst for oxidation of alkenes with tert-butylhydroperoxide. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2009.11.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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53
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de Souza B, Bortoluzzi AJ, Bortolotto T, Fischer FL, Terenzi H, Ferreira DEC, Rocha WR, Neves A. DNA photonuclease activity of four new copper(ii) complexes under UV and red light: theoretical/experimental correlations with active species generation. Dalton Trans 2010; 39:2027-35. [DOI: 10.1039/b920122j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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54
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Wong YL, Tong LH, Dilworth JR, Ng DKP, Lee HK. New dioxo–molybdenum(vi) and –tungsten(vi) complexes with N-capped tripodal N2O2 tetradentate ligands: Synthesis, structures and catalytic activities towards olefin epoxidation. Dalton Trans 2010; 39:4602-11. [DOI: 10.1039/b926864b] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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55
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Lal RA, Choudhury S, Ahmed A, Borthakur R, Asthana M, Kumar A. Synthesis of homobimetallic molybdenum(VI) complex of bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone and its reaction with electron and proton bases. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2010; 75:212-224. [PMID: 19914126 DOI: 10.1016/j.saa.2009.10.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2009] [Accepted: 10/08/2009] [Indexed: 05/28/2023]
Abstract
The diamagnetic dioxomolybdenum(VI) complex [(MoO(2))(2)(CH(2)L)(H(2)O)(2)]H(2)O (1) has been isolated in solid state from reaction of MoO(2)(acac)(2) with bis(2-hydroxy-1-naphthaldehyde)malonoyldihydrazone (CH(2)LH(4)) in 3:1 molar ratio in ethanol at higher temperature. The reaction of the complex (1) with electron donor bases gives diamagnetic molybdenum(VI) complexes having composition [Mo(2)O(5)(CH(2)LH(2))].2A.2H(2)O (where A=pyridine (py, 2), 2-picoline (2-pic, 3), 3-picoline (3-pic, 4), 4-picoline (4-pic, 5)). Further, when the complex (1) is allowed to react with protonic bases such as isonicotinoylhydrazine (inhH(3)) and salicyloylhydrazine (slhH(3)), reduction of molybdenum(VI) centre occurs leading to isolation of homobimetallic molybdenum(V) complexes [Mo(2)(CH(2)L)(inh)(2)(H(2)O)(2)] (6) and [Mo(2)(CH(2)L)(slh)(2)] (7), respectively. The composition of the complexes has been established by analytical, thermo-analytical and molecular weight data. The structure of the molybdenum(VI) complexes (1)-(5) has been established by electronic, IR, (1)H NMR and (13)C NMR spectral studies while those of the complexes (6) and (7) by magnetic moment, electronic, IR and EPR spectral studies. The dihydrazone is coordinated to the metal centres in staggered configuration in complex (1) while in anti-cis configuration in complexes (2)-(7). The complexes (6) and (7) possess magnetic moment of 2.95 and 3.06 BM, respectively, indicating presence of two magnetic centre in the complexes per molecule each with one unpaired electron on each metal centre without any metal-metal interaction. The electronic spectra of the complexes are dominated by strong charge transfer bands. All of the complexes involve six coordinated molybdenum centre with octahedral arrangement of donor atoms except in the complex (6), in which the molybdenum centre has rhombic arrangement of ligand donor atoms. The probable mechanism for generation of oxo-group in the complexes (2)-(5) involving coordinated water molecule has been proposed.
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Affiliation(s)
- Ram A Lal
- Department of Chemistry, North-Eastern Hill University, Shillong, Meghalaya, India.
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Lal RA, Chakrabarty M, Choudhury S, Ahmed A, Borthakur R, Kumar A. Synthesis and spectral characterization of homobimetallic molybdenum(VI) complexes derived from bis(2-hydroxy-1-naphthaldehyde)succinoyldihydrazone. J COORD CHEM 2009. [DOI: 10.1080/00958970903259451] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Ram A. Lal
- a Department of Chemistry , North-Eastern Hill University , Shillong-793022 , Meghalaya , India
| | - Mithun Chakrabarty
- a Department of Chemistry , North-Eastern Hill University , Shillong-793022 , Meghalaya , India
| | - Sanjesh Choudhury
- a Department of Chemistry , North-Eastern Hill University , Shillong-793022 , Meghalaya , India
| | - Aziz Ahmed
- a Department of Chemistry , North-Eastern Hill University , Shillong-793022 , Meghalaya , India
| | - Roshmita Borthakur
- a Department of Chemistry , North-Eastern Hill University , Shillong-793022 , Meghalaya , India
| | - Arvind Kumar
- b Academia Sinica, Institute of Chemistry , 128 Academia Road, Sec.2, Nangkang, Taipei, 115, Taiwan , Republic of China
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Trach YB, Makota OI. Kinetic study of hydroperoxide epoxidation of 1-octene in the presence of molybdenum disilicide as a catalyst in a low concentration range of olefin. INT J CHEM KINET 2009. [DOI: 10.1002/kin.20436] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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59
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Bagherzadeh M, Latifi R, Tahsini L, Amani V, Ellern A, Keith Woo L. Synthesis, characterization and crystal structure of a dioxomolybdenum(VI) complex with a N,O type bidentate Schiff base ligand as a catalyst for homogeneous oxidation of olefins. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.05.036] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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60
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ZHOU X, GAI H, WANG J, ZHANG S, YANG J, ZHANG S. Oxidation of Benzothiophenes Using Tert-amyl Hydroperoxide. Chin J Chem Eng 2009. [DOI: 10.1016/s1004-9541(08)60192-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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61
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Al-Ajlouni AM, Günyar A, Zhou MD, Baxter PNW, Kühn FE. Adduct Formation of Dichloridodioxidomolybdenum(VI) and Methyltrioxidorhenium(VII) with a Series of Bidentate Nitrogen Donor Ligands. Eur J Inorg Chem 2009. [DOI: 10.1002/ejic.200801103] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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62
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Günyar A, Zhou MD, Drees M, Baxter PNW, Bassioni G, Herdtweck E, Kühn FE. Studies on bis(halogeno) dioxomolybdenum(VI)-bipyridine complexes: Synthesis and catalytic activity. Dalton Trans 2009:8746-54. [DOI: 10.1039/b909075d] [Citation(s) in RCA: 22] [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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63
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Bagherzadeh M, Amini M. Synthesis, characterization and catalytic study of a novel iron(III)-tridentate Schiff base complex in sulfide oxidation by UHP. INORG CHEM COMMUN 2009. [DOI: 10.1016/j.inoche.2008.10.023] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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64
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Ruddy DA, Tilley TD. Kinetics and Mechanism of Olefin Epoxidation with Aqueous H2O2 and a Highly Selective Surface-Modified TaSBA15 Heterogeneous Catalyst. J Am Chem Soc 2008; 130:11088-96. [DOI: 10.1021/ja8027313] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel A. Ruddy
- Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - T. Don Tilley
- Department of Chemistry, University of California, Berkeley, California 94720, and Chemical Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
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65
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Barrio L, Campos-Martín JM, de Frutos MP, Fierro JLG. Alkene Epoxidation with Ethylbenzene Hydroperoxides Using Molybdenum Heterogeneous Catalysts. Ind Eng Chem Res 2008. [DOI: 10.1021/ie800262x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Laura Barrio
- Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain, and Centro de Tecnología Repsol YPF, A-5, Km. 18, 28930 Móstoles, Madrid, Spain
| | - Jose M. Campos-Martín
- Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain, and Centro de Tecnología Repsol YPF, A-5, Km. 18, 28930 Móstoles, Madrid, Spain
| | - M. Pilar de Frutos
- Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain, and Centro de Tecnología Repsol YPF, A-5, Km. 18, 28930 Móstoles, Madrid, Spain
| | - Jose L. G. Fierro
- Instituto de Catálisis y Petroleoquímica, CSIC, Marie Curie 2, Cantoblanco, 28049 Madrid, Spain, and Centro de Tecnología Repsol YPF, A-5, Km. 18, 28930 Móstoles, Madrid, Spain
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66
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Song Y, Xu Z, Sun Q, Su B, Gao Q, Liu H, Zhao J. Synthesis, structures, and characterization of copper(II), nickel(II), and cobalt(III) metal complexes derived from an asymmetric bidentate Schiff-base ligand. J COORD CHEM 2008. [DOI: 10.1080/00958970701509768] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Yanhong Song
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Zhanwei Xu
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Qingjin Sun
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Biyun Su
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Quanchang Gao
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Huaqiang Liu
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Jianshe Zhao
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
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67
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Feng L, Urnezius E, Luck RL. Cyclooctene epoxidation with H2O2 and single crystal X-ray determined crystal structures of new molybdenum and tungsten catalysts bearing the hydrophilic ligand hydroxymethyldiphenylphosphine oxide. J Organomet Chem 2008. [DOI: 10.1016/j.jorganchem.2007.11.018] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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68
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Burke AJ. Chiral oxoperoxomolybdenum(VI) complexes for enantioselective olefin epoxidation: Some mechanistic and stereochemical reflections. Coord Chem Rev 2008. [DOI: 10.1016/j.ccr.2007.05.002] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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69
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Song Y, Xu Z, Sun Q, Su B, Gao Q, Liu H, Zhao J. Chloro-bridged complexes of copper(II) and manganese(II) derived from unsymmetric bidentate ligands: synthesis, crystal structure and characterization. J COORD CHEM 2007. [DOI: 10.1080/00958970701266484] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Affiliation(s)
- Yanhong Song
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Zhanwei Xu
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Qingjin Sun
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Biyun Su
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Quanchang Gao
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Huaqiang Liu
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
| | - Jianshe Zhao
- a Shaanxi Key Laboratory of Physico-Inorganic Chemistry, Department of Chemistry , Northwest University , Xi’an, Shaanxi 710069, China
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70
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Synthesis and catalytic properties in olefin epoxidation of dioxomolybdenum(vi) complexes bearing a bidentate or tetradentate salen-type ligand. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.molcata.2007.01.050] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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71
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Pouralimardan O, Chamayou AC, Janiak C, Hosseini-Monfared H. Hydrazone Schiff base-manganese(II) complexes: Synthesis, crystal structure and catalytic reactivity. Inorganica Chim Acta 2007. [DOI: 10.1016/j.ica.2006.08.056] [Citation(s) in RCA: 238] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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72
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Lu XM, Pei XH, Wang XJ, Ye CH. The Reaction of Molybdenum with 2,3-Dihydroxynaphthalene. CHINESE J CHEM 2007. [DOI: 10.1002/cjoc.200790085] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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73
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Lyashenko G, Jancik V, Pal A, Herbst-Irmer R, Mösch-Zanetti NC. Dioxomolybdenum(VI) and dioxotungsten(VI) complexes supported by an amido ligand. Dalton Trans 2006:1294-301. [PMID: 16505908 DOI: 10.1039/b514873a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Stepwise addition of one equivalent of n-butyllithium and trimethylsilyl chloride to 2-tert-butylmercaptoaniline affords the new ligand 1-(Me3SiNH)-2-(t-BuS)C6H4 (LH), that reacts with one equivalent of butyllithium to its lithium salt LLi. Dioxodichloromolybdenum [MoO2Cl2] and dioxodichlorotungsten dimethoxyethane [WO2Cl2(dme)] react in tetrahydrofuran solution at low temperature with two equivalents LLi to monomeric dioxomolybdenum(VI) [MoO2L2] (1) and dioxotungsten(VI) complex [WO2L2] (2) employing two bidentate amido thioether ligands. The crystallographic determination of the molecular structures of 1 and 2 show evidence for M...S contacts. The reaction of [MoO2Cl2] with LLi in tetrahydrofuran solution at room temperature leads next to 1 to two compounds where silyl group migration from nitrogen to oxygen atoms occurs forming [Mo(=NL')2(OSiMe)2] (3) and [Mo(=NL')2(OSiMe3)L] (4, L' = N-2-t-BuSC6H4) as determined by NMR spectroscopy. Compound 4 was isolated in low yield and its molecular structure determined by X-ray crystallography. Higher yields of a bisimido complex can be obtained by the direct reaction of one equivalent of LLi with [Mo(NAr)2Cl2(dme)] (Ar = 2,6-Me2C6H4) forming [Mo(NAr)2LCl] (5).
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Affiliation(s)
- Ganna Lyashenko
- Institut für Anorganische Chemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D-37077, Göttingen, Germany
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74
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Veiros LF, Prazeres A, Costa PJ, Romão CC, Kühn FE, José Calhorda M. Olefin epoxidation with tert-butyl hydroperoxide catalyzed by MoO2X2L complexes: a DFT mechanistic study. Dalton Trans 2006:1383-9. [PMID: 16518507 DOI: 10.1039/b515484g] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
DFT calculations suggest that the catalytic epoxidation of olefins by Mo(vi) complexes, modeled by MoO2Br2(MeN=C(H)-C(H)=NMe), in the presence of MeOOH, the model for tert-butyl hydroperoxide, starts with a hydrogen transfer from the peroxide to one of the terminal Mo=O oxygen atoms and the remaining MeOO anion binds as a seventh ligand, forming a five-membered Mo-O(alpha)-O(beta)(Me)...H-O-Mo ring held together by a hydrogen bond. In the second step, a concerted approach of ethylene to the Mo-O(alpha) bond gives rise to an intermediate containing a seven-membered Mo-C-C-O(alpha)-O(beta)(Me)...H-O-Mo ring. In the final step, decomposition of the intermediate leads to the starting complex, alcohol and the epoxide. The activation energy for the addition of the olefin (second step) is the highest one, in agreement with available kinetic studies showing that the catalyst formation is not always a rate-limiting step. DFT calculations also show that the alcohol by-product (MeOH) can react with the starting complex, competing with ROOH and hence leading to the progressive catalyst poisoning, which has been observed experimentally.
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75
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Shakya R, Imbert C, Hratchian HP, Lanznaster M, Heeg MJ, McGarvey BR, Allard M, Schlegel HB, Verani CN. Structural, spectroscopic, and electrochemical behavior of trans-phenolato cobalt(iii) complexes of asymmetric NN′O ligands as archetypes for metallomesogens. Dalton Trans 2006:2517-25. [PMID: 16718335 DOI: 10.1039/b514190g] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In order to understand and predict structural, redox, magnetic, and optical properties of more complex and potentially mesogenic electroactive compounds such as [Co(III)(L(t-BuLC))2]ClO4 (1), five archetypical complexes of general formula [Co(III)(L(RA))2]ClO4, where R = H (2), tert-butyl (3), methoxy (4), nitro (5), and chloro (6), were obtained and studied by means of several spectrometric, spectroscopic, and electrochemical methods. The complexes 2, 4, and 6 were characterized by single-crystal X-ray diffraction, and show the metal center in an approximate D2h symmetry. Experimental results support the fact that the electron donating or withdrawing nature of the phenolate-appended substituents changes dramatically the redox and spectroscopic properties of these compounds. The 3d6 electronic configuration of the metal ion dominates the overall geometry adopted by these compounds with the phenolate rings occupying trans positions to one another. Formation of phenoxyl radicals has been observed for 1, 3, and 6, but irreversible ligand oxidation takes place upon bulk electrolysis. These data were compared to detailed B3LYP/6-31G (d)-level computational calculations and have been used to account for the results observed. A comparison between compound 1 and archetype 3, validates the approach of using archetypical models to study metal-containing soft materials.
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Affiliation(s)
- Rajendra Shakya
- Department of Chemistry, Wayne State University, 5101 Cass Ave., Detroit, MI 48202, USA
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76
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Kretz T, Bats JW, Losi S, Wolf B, Lerner HW, Lang M, Zanello P, Wagner M. Hydroquinone-bridged dinuclear CuII complexes and single-crystalline CuII coordination polymers. Dalton Trans 2006:4914-21. [PMID: 17047740 DOI: 10.1039/b609426k] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Cationic dinuclear Cu(II) complexes 3 and 4 have been prepared using the novel hydroquinone-based imine chelators 2,5-((i)Pr(2)NCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (1) and 2,5-(pyCH(2)CH(2)N[double bond, length as m-dash]CH)(2)-1,4-(OH)(2)-C(6)H(2) (2), respectively (py = 2-pyridyl). X-Ray quality crystals of both complexes were grown from their DMF solutions. The sterically more encumbered compound crystallizes in the form of discrete dinuclear entities with Cu(II) centres in a distorted square-planar ligand environment (one coordination site is occupied by a DMF molecule). The pyridyl derivative 4 features dinuclear hydroquinone-bridged subunits similar to 3. However, the Cu(II) ions are now six-coordinate with two DMF molecules at an axial and an equatorial position of a Jahn-Teller-distorted octahedron. Moreover, the dinuclear subunits are no longer isolated but linked with each other via bridging hydroquinone oxygen atoms which occupy the second apical position of each octahedron. The structure suggests that the magnetic properties of the resulting coordination polymer of 4 could be described by a model valid for dimerized spin chains. As a result of this analysis the antiferromagnetic coupling constants J(1)/k(B) = 9.9 K (intradimer) and J(2)/k(B) = 0.9 K (interdimer) are obtained. Both in 3 and in 4, the hydroquinone --> semiquinone transition of the central bridging unit (E degrees ' = + 0.57 V, 3; E degrees ' = + 0.51 V, 4; DMF; vs. SCE) displays features of chemical reversibility. In the case of , reduction of Cu(II) centres requires a peak potential of E(p) = - 0.42 V.
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Affiliation(s)
- Tonia Kretz
- Institut für Anorganische Chemie, J.W. Goethe-Universität Frankfurt, Max-von-Laue-Strasse 7, D-60438, Frankfurt, Main, Germany
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77
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Barker JE, Ren T. Sulfide oxygenation by tert-butyl hydroperoxide with mononuclear (Me3TACN)Mn catalysts. Tetrahedron Lett 2005. [DOI: 10.1016/j.tetlet.2005.08.033] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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78
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Imbert C, Hratchian HP, Lanznaster M, Heeg MJ, Hryhorczuk LM, McGarvey BR, Schlegel HB, Verani CN. Influence of Ligand Rigidity and Ring Substitution on the Structural and Electronic Behavior of Trivalent Iron and Gallium Complexes with Asymmetric Tridentate Ligands. Inorg Chem 2005; 44:7414-22. [PMID: 16212367 DOI: 10.1021/ic050658j] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Species 1-6 are [M(III)(L)2]ClO4 complexes formed with the PhO--CH=N-CH2-Py imines, (L(I))- and (L(tBuI))-, and PhO--CH2-NH-CH2-Py amines, (L(A))- and (L(tBuA))-, in which PhO- is a phenolate ring and Py is a pyridine ring and the prefix tBu indicates the presence of tertiary butyl groups occupying the positions 4 and 6 of the phenol ring. Monometallic species with d5 high-spin iron (1, 2, 3, 4) and d10 gallium (5, 6) were synthesized and characterized to assess the influence of the ligand rigidity and the presence of tertiary butyl-substituted phenol rings on their steric, electronic, and redox behavior. Characterization by elemental analysis, mass spectrometry, IR, UV-visible, and EPR spectroscopies, and electrochemistry has been performed, and complexes [FeIII(L(tBuI))2]ClO4 (2), [FeIII(L(tBuA))2]ClO4 (4), and [Ga(III)(L(tBuI))2]ClO4 (5) have been characterized by X-ray crystallography. The crystal structures show the imine ligands meridionally coordinated to the metal centers, whereas the amine ligands are coordinate in a facial mode. Cyclic voltammetry shows that the complexes with the ligands (L(tBuI))- and (L(tBuA))- were able to generate ligand-based phenoxyl radicals, whereas unsubstituted ligands displayed ill-defined redox processes. EPR spectroscopy supports high-spin configurations for the iron complexes. UV-visible spectra are dominated by charge-transfer phenomena, and imine compounds exhibit dramatic hyperchromism when compared to equivalent amines. The tertiary butyl groups on the phenolate ring enhance this trend. Detailed B3LYP/6-31G(d)-level calculations have been used to account for the results observed.
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Affiliation(s)
- Camille Imbert
- Department of Chemistry, Wayne State University, 5101 Cass Ave. Detroit, Michigan 48202, USA
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79
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Sensato FR, Custodio R, Longo E, Safont VS, Andrés J. Why Do Peroxomolybdenum Complexes Chemoselectively Oxidize the Sulfur Centers of Unsaturated Sulfides and Sulfoxides? A DFT Analysis. European J Org Chem 2005. [DOI: 10.1002/ejoc.200500007] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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80
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Jimtaisong A, Luck RL. Synthesis, Crystal Structure and Reactivity of Mo4O6(O2)2(μ3-O)2{(μ2-O,μ3-OC8H14}2(OPMePh2)2: A Self-assembled Tetranuclear Cluster Containing Two Peroxide and Two Trans-Cyclooctanediol Ligands*. J CLUST SCI 2005. [DOI: 10.1007/s10876-005-4404-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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81
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Al-Ajlouni A, Valente AA, Nunes CD, Pillinger M, Santos AM, Zhao J, Romão CC, Gonçalves IS, Kühn FE. Kinetics of Cyclooctene Epoxidation withtert-Butyl Hydroperoxide in the Presence of [MoO2X2L]-Type Catalysts (L = Bidentate Lewis Base). Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400852] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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82
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Mordini A, Peruzzi D, Russo F, Valacchi M, Reginato G, Brandi A. Superbase-promoted rearrangement of oxiranes to cyclopropanes. Tetrahedron 2005. [DOI: 10.1016/j.tet.2005.01.102] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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83
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Coppens P, Iversen B, Larsen FK. The use of synchrotron radiation in X-ray charge density analysis of coordination complexes. Coord Chem Rev 2005. [DOI: 10.1016/j.ccr.2004.02.019] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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84
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Synthesis of bis[N,O-{2′-pyridyl-methanolate}]dioxomolybdenum(VI) epoxidation catalyst and novel crystal structure derived from X-ray diffraction and DFT calculations. ACTA ACUST UNITED AC 2004. [DOI: 10.1016/j.molcata.2003.12.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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85
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Valente AA, Moreira J, Lopes AD, Pillinger M, Nunes CD, Romão CC, Kühn FE, Gonçalves IS. Dichloro and dimethyl dioxomolybdenum(vi)–diazabutadiene complexes as catalysts for the epoxidation of olefins. NEW J CHEM 2004. [DOI: 10.1039/b311114h] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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86
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Nakayama Y, Baba Y, Yasuda H, Kawakita K, Ueyama N. Stereospecific Polymerizations of Conjugated Dienes by Single Site Iron Complexes Having Chelating N,N,N-Donor Ligands. Macromolecules 2003. [DOI: 10.1021/ma0300802] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yuushou Nakayama
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan, and Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Yuji Baba
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan, and Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Hajime Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan, and Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Keiko Kawakita
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan, and Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
| | - Norikazu Ueyama
- Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan, and Department of Macromolecular Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan
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87
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Fristrup P, Tanner D, Norrby PO. Updating the asymmetric osmium-catalyzed dihydroxylation (AD) mnemonic: Q2MM modeling and new kinetic measurements. Chirality 2003; 15:360-8. [PMID: 12666245 DOI: 10.1002/chir.10214] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mnemonic device for predicting stereoselectivities in the Sharp-less asymmetric dihydroxylation (AD) reaction has been updated based on extensive computational studies. Kinetic measurements from competition reactions validate the new proposal. The interactions responsible for the high stereoselectivity in the title reaction are analyzed in detail and mapped onto the mnemonic device.
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Affiliation(s)
- Peter Fristrup
- Department of Chemistry, Organic Chemistry, Technical University of Denmark, Lyngby, Denmark
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88
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Dorosheva TS, Bryliakov KP, Talsi EP. Multinuclear NMR-spectroscopic characterization of alkylperoxo complexes of molybdenum(VI). MENDELEEV COMMUNICATIONS 2003. [DOI: 10.1070/mc2003v013n01abeh001636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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89
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Wong YL, Ng DKP, Lee HK. New chloro, mu-oxo, and alkyl derivatives of dioxomolybdenum(VI) and -tungsten(VI) complexes chelated with N(2)O tridentate ligands: synthesis and catalytic activities toward olefin epoxidation. Inorg Chem 2002; 41:5276-85. [PMID: 12354062 DOI: 10.1021/ic020173k] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new series of cis-dioxomolybdenum(VI) complexes MoO(2)(L(n))Cl (n = 1-5) were prepared by the reaction of MoO(2)Cl(2)(DME) (DME = 1,2-dimethoxyethane) with 2-N-(2-pyridylmethyl)aminophenol (HL(1)) or its N-alkyl derivatives (HL(n)) (n = 2-5) in the presence of triethylamine. The new mu-oxo dimolybdenum compounds [MoO(2)(L(n))](2)O (n = 1, 4, 5, 7) were also prepared by treating the corresponding ligand HL(n) with MoO(2)(acac)(2) (acac = acetylacetonate) in warm methanolic solutions or (NH(4))(6)[Mo(7)O(24)].4H(2)O in the presence of dilute HCl. Treatment of MoO(2)(L(1))Cl or [MoO(2)(L(1))](2)O with the Grignard reagent Me(3)SiCH(2)MgCl gave the alkyl compound MoO(2)(L(1))(CH(2)SiMe(3)), which represents the first example of dioxomolybdenum(VI) alkyl complex supported by a N(2)O-type ancillary ligand. The analogous chloro and mu-oxo tungsten derivatives WO(2)(L(n))Cl (n = 6, 7) and [WO(2)(L(n))](2)O (n = 1, 4, 6, 7) were prepared by the reaction of WO(2)Cl(2)(DME) with HL(n) in the presence of triethylamine. Similar to their molybdenum analogues, the tungsten alkyl complexes WO(2)(L(n))(R) (n = 6, 7; R = Me, Et, CH(2)SiMe(3), C(6)H(4)(t)Bu-4) were synthesized by treating WO(2)(L(n))Cl or [WO(2)(L(n))](2)O (n = 6, 7) with the appropriate Grignard reagents. The catalytic properties of selected dioxo-Mo(VI) and -W(VI) chloro and mu-oxo complexes toward epoxidation of styrene by tert-butyl hydroperoxide (TBHP) were also investigated.
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Affiliation(s)
- Yee-Lok Wong
- Department of Chemistry, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong SAR, People's Republic of China
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90
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Kühn FE, Xue WM, Al-Ajlouni A, Santos AM, Zang S, Romão CC, Eickerling G, Herdtweck E. Synthesis and catalytic application of octahedral lewis base adducts of dichloro and dialkyl dioxotungsten(VI). Inorg Chem 2002; 41:4468-77. [PMID: 12184764 DOI: 10.1021/ic0200085] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Complexes of the composition W(O)(2)(Cl)(2)L(2) and W(O)(2)(R)(2)L(2) (R = Me, Et; L(2) = bidentate Lewis base ligand) have been prepared and are fully characterized (including an exemplary X-ray crystal structure of W(O)(2)(Cl)(2)(4,4'-di-tert-butyl-2,2'-bipyridine)). This latter compound crystallizes in the orthorhombic space group P2(1)2(1)2(1) with a = 8.3198(1) A, b = 13.3224(2) A, c = 18.0415(2) A, and Z = 4. The title complexes are applied as catalysts in olefin epoxidation catalysis with tert-butyl hydroperoxide (TBHP) as the oxidizing agent. The W(VI) complexes display only moderate turnover frequencies but can be reused several times without loss of catalytic activity. The highest activity can be achieved at reaction temperatures of ca. 90 degrees C. Chloro derivatives are somewhat more active than alkyl complexes, and sterically less crowded complexes show also higher activities than their congeners with bulky ligands L(2). Kinetic examinations show that the catalyst formation is the rate determining step and it is observed that tert-butyl alcohol, the byproduct of the epoxidation reaction, acts as a competitor for TBHP, thus lowering the reaction velocity during the course of the reaction but not irreversibly destroying the catalyst.
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Affiliation(s)
- Fritz E Kühn
- Anorganisch-Chemisches Institut, Technischen Universität München, Lichtenbergstrasse 4, D-85747 Garching bei München, Germany.
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91
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Effective homogeneous molybdenum catalyst for linear terminal alkenes epoxidation with organic hydroperoxide. CATAL COMMUN 2002. [DOI: 10.1016/s1566-7367(02)00106-1] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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92
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Catasús M, Moyano A, Aggarwal VK. Sulphur ylide-mediated stereoselective synthesis of a stable ferrocenyl epoxide. Tetrahedron Lett 2002. [DOI: 10.1016/s0040-4039(02)00578-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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