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Conradie J, Alemayehu AB, Ghosh A. Iridium(VII)-Corrole Terminal Carbides Should Exist as Stable Compounds. ACS ORGANIC & INORGANIC AU 2021; 2:159-163. [PMID: 36855452 PMCID: PMC9955125 DOI: 10.1021/acsorginorgau.1c00029] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Scalar-relativistic DFT calculations with multiple exchange-correlation functionals and large basis sets foreshadow the existence of stable iridium(VII)-corrole terminal carbide derivatives. For the parent compound Ir[Cor](C), OLYP/STO-TZ2P calculations predict a short Ir-C bond distance of 1.69 Å, a moderately domed macrocycle with no indications of ligand noninnocence, a surprisingly low electron affinity of ∼1.1 eV, and a substantial singlet-triplet gap of ∼1.8 eV. These results, and their essential invariance with respect to the choice of the exchange-correlation functional, lead us to posit that Ir(VII)-corrole terminal carbide complexes should be isolable and indefinitely stable under ambient conditions.
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Affiliation(s)
- Jeanet Conradie
- Department
of Chemistry, UiT The Arctic University
of Norway, N-9037 Tromsø, Norway,Department
of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, Republic of South Africa
| | - Abraham B. Alemayehu
- Department
of Chemistry, UiT The Arctic University
of Norway, N-9037 Tromsø, Norway
| | - Abhik Ghosh
- Department
of Chemistry, UiT The Arctic University
of Norway, N-9037 Tromsø, Norway,
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2
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Braband H, Benz M, Spingler B, Conradie J, Alberto R, Ghosh A. Relativity as a Synthesis Design Principle: A Comparative Study of [3 + 2] Cycloaddition of Technetium(VII) and Rhenium(VII) Trioxo Complexes with Olefins. Inorg Chem 2021; 60:11090-11097. [PMID: 34255507 PMCID: PMC8388117 DOI: 10.1021/acs.inorgchem.1c00995] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
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The difference in [3 + 2] cycloaddition reactivity between fac-[MO3(tacn)]+ (M = Re, 99Tc; tacn = 1,4,7-triazacyclononane) complexes has been reexamined
with a selection of unsaturated substrates including sodium 4-vinylbenzenesulfonate,
norbornene, 2-butyne, and 2-methyl-3-butyn-2-ol (2MByOH). None of
the substrates was found to react with the Re cation in water at room
temperature, whereas the 99Tc reagent cleanly yielded the [3 + 2] cycloadducts. Interestingly,
a bis-adduct was obtained as the sole product for 2MByOH, reflecting
the high reactivity of a 99TcO-enediolato monoadduct. On
the basis of scalar relativistic and nonrelativistic density functional
theory calculations of the reaction pathways, the dramatic difference
in reactivity between the two metals has now been substantially attributed to differences in relativistic effects, which are much
larger for the 5d metal. Furthermore, scalar-relativistic ΔG values were found to decrease along the series propene
> norbornene > 2-butyne > dimethylketene, indicating major variations
in the thermodynamic driving force as a function of the unsaturated
substrate. The suggestion is made that scalar-relativistic effects,
consisting of greater destabilization of the valence electrons of
the 5d elements compared with those of the 4d elements, be viewed
as a new design principle for novel 99mTc/Re radiopharmaceuticals,
as well as more generally in heavy-element coordination chemistry. Room temperature cycloaddition reactivity of fac-[99TcO3(tacn)]+ (tacn = 1,4,7-triazacyclononane)
with a variety of unsaturated substrates and the lack of such reactivity
for fac-[ReO3(tacn)]+ appears
largely attributable to much stronger relativistic effects for Re
relative to Tc, based on relativistic density functional theory calculations.
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Affiliation(s)
- Henrik Braband
- Department of Chemistry, University of Zurich, Zürich 8057, Switzerland
| | - Michael Benz
- Department of Chemistry, University of Zurich, Zürich 8057, Switzerland
| | - Bernhard Spingler
- Department of Chemistry, University of Zurich, Zürich 8057, Switzerland
| | - Jeanet Conradie
- Department of Chemistry, UiT-The Arctic University of Norway, Tromsø N-9037, Norway.,Department of Chemistry, University of the Free State, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Roger Alberto
- Department of Chemistry, University of Zurich, Zürich 8057, Switzerland
| | - Abhik Ghosh
- Department of Chemistry, UiT-The Arctic University of Norway, Tromsø N-9037, Norway
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3
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Petel BE, Matson EM. Oxygen-atom vacancy formation and reactivity in polyoxovanadate clusters. Chem Commun (Camb) 2020; 56:13477-13490. [DOI: 10.1039/d0cc05920j] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Overview of recent work detailing oxygen-deficient polyoxovanadate clusters as models for reducible metal oxides: toward gaining a fundamental understanding the consequences of vacancy formation on metal oxide surfaces during catalysis.
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4
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Abstract
Metal-oxyl (Mn+-O•) complexes having an oxyl radical ligand, which are electronically equivalent to well-known metal-oxo (M(n+1)+═O) complexes, are surveyed as a new category of metal-based oxidants. Detection and characterization of Mn+-O• species have been made in some cases, although proposals and characterization of the species are mostly done on the basis of density functional theory (DFT) calculations. The reactivity of Mn+-O• complexes will provide a way to achieve potentially difficult oxidative conversion of substrates. This Viewpoint will provide state-of-the-art knowledge on the Mn+-O• species in terms of the formation, characterization, and DFT-based proposals to shed light on the characteristics of the intriguing oxidatively active species.
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Affiliation(s)
- Yoshihiro Shimoyama
- Department of Chemistry, Faculty of Pure and Applied Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-8571 , Japan.,Interdisciplinary Research Center for Catalytic Chemistry , National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba , Ibaraki 305-8565 , Japan
| | - Takahiko Kojima
- Department of Chemistry, Faculty of Pure and Applied Sciences , University of Tsukuba , Tsukuba , Ibaraki 305-8571 , Japan
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5
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Petel BE, Meyer RL, Brennessel WW, Matson EM. Oxygen atom transfer with organofunctionalized polyoxovanadium clusters: O-atom vacancy formation with tertiary phosphanes and deoxygenation of styrene oxide. Chem Sci 2019; 10:8035-8045. [PMID: 31853359 PMCID: PMC6837047 DOI: 10.1039/c9sc02882j] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 07/13/2019] [Indexed: 12/22/2022] Open
Abstract
We report a rare example of oxygen atom transfer (OAT) from a polyoxometalate cluster to a series of tertiary phosphanes followed by OAT from styrene oxide to the reduced scaffold, resulting in the formation of styrene.
We report a rare example of oxygen atom transfer (OAT) from a polyoxometalate cluster to a series of tertiary phosphanes. Addition of PR3 (PR3 = PMe3, PMe2Ph, PMePh2, PPh3) to a neutral methoxide-bridged polyoxovanadate-alkoxide (POV-alkoxide) cluster, [V6O7(OMe)12]0, results in isolation of a reduced structure with phosphine oxide datively coordinated to a site-differentiated VIII ion. A positive correlation between the steric and electronic properties of the phosphane and the reaction rate was observed. Further investigation of the steric influence of the alkoxy-bridged clusters on OAT was probed through the use of POV clusters with bridging alkoxide ligands of varying chain length ([V6O7(OR′)12]; R′ = Et, nPr). These investigations expose that steric hinderance of the vanadyl moieties has significant influence on the rate of OAT. Finally, we report the reactivity of the reduced POV-alkoxide clusters with styrene oxide, resulting in the deoxygenation of the substrate to generate styrene. This result is the first example of epoxide deoxygenation using homometallic polyoxometalate clusters, demonstrating the potential for mono-vacant Lindqvist clusters to catalyze the removal of oxygen atoms from organic substrates.
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Affiliation(s)
- Brittney E Petel
- Department of Chemistry , University of Rochester , Rochester , New York 14627 , USA .
| | - Rachel L Meyer
- Department of Chemistry , University of Rochester , Rochester , New York 14627 , USA .
| | - William W Brennessel
- Department of Chemistry , University of Rochester , Rochester , New York 14627 , USA .
| | - Ellen M Matson
- Department of Chemistry , University of Rochester , Rochester , New York 14627 , USA .
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6
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Chrysochos N, Ahmadi M, Wahlefeld S, Rippers Y, Zebger I, Mroginski MA, Schulzke C. Comparison of molybdenum and rhenium oxo bis-pyrazine-dithiolene complexes - in search of an alternative metal centre for molybdenum cofactor models. Dalton Trans 2019; 48:2701-2714. [PMID: 30720825 DOI: 10.1039/c8dt04237c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A pair of structurally precise analogues of molybdenum and rhenium complexes, [Et4N]/K2[MoO(prdt)2] and K[ReO(prdt)2] (prdt = pyrazine-2,3-dithiolene), were synthesized. These complexes serve as structural models for the active sites of bacterial molybdenum cofactor containing enzymes. They were comprehensively characterized and investigated by NMR, computationally supported IR and resonance Raman spectroscopy, cyclic voltammetry, mass spectrometry, elemental analysis and single-crystal X-ray diffraction. All compiled data are discussed in the context of comparing chemical and electronic structures and consequences thereof. This study constitutes the first investigation of a potential alternative Moco model system bearing rhenium as the central metal in an identical coordination environment to its molybdenum analogue. Structural evaluation revealed a slightly stronger M[double bond, length as m-dash]O bond in the rhenium complex in accordance with spectroscopic results, i.e. observed bond strengths. Thermodynamic parameters for the redox processes MoIV ↔ MoV and ReIV ↔ ReV were obtained by temperature dependent cyclic voltammetry. In contrast to molybdenum, rhenium loses entropy upon reduction and its redox potential is more temperature sensitive, indicating more significant differences than the respective diagonal relationship between the two metals in the periodic table might suggest and questioning rhenium's suitability as a functional artificial active site metal.
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Affiliation(s)
- Nicolas Chrysochos
- Institut für Biochemie, Universität Greifswald, Felix-Hausdorff-Straße 4, 17487 Greifswald, Germany.
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7
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Ibdah A, Alduwikat S. Thermochemistry and Bond Nature of Oxo and Thio Ligands in Rhenium(V) Catalysts and Rhenium(VII) Intermediates: Density Functional Calculations. Eur J Inorg Chem 2018. [DOI: 10.1002/ejic.201800049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Abdellatif Ibdah
- Department of Chemistry Jordan University of Science and Technology Irbid Jordan
| | - Salwa Alduwikat
- Department of Chemistry Jordan University of Science and Technology Irbid Jordan
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8
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Yao L, Li Y, Huang L, Guo K, Ren G, Wu Z, Lei Q, Fang W, Xie H. A DFT study on the mechanisms of hydrogenation and hydrosilylation of nitrous oxide catalyzed by a ruthenium PNP pincer complex. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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9
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Sathdeo S, Schoultz X, Gerber TI, Betz R, Hosten EC. Reactivity of a benzothiazole-thiourea derivative with the oxorhenium(V) core: Isolation of rhenium(III) and (V) complexes. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.03.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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10
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Xie H, Liu C, Yuan Y, Zhou T, Fan T, Lei Q, Fang W. Oxidation of phenyl and hydride ligands of bis(pentamethylcyclopentadienyl)hafnium derivatives by nitrous oxide via selective oxygen atom transfer reactions: insights from quantum chemistry calculations. Dalton Trans 2016; 45:1152-9. [PMID: 26660046 DOI: 10.1039/c5dt03264d] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The mechanisms for the oxidation of phenyl and hydride ligands of bis(pentamethylcyclopentadienyl)hafnium derivatives (Cp* = η(5)-C5Me5) by nitrous oxide via selective oxygen atom transfer reactions have been systematically studied by means of density functional theory (DFT) calculations. On the basis of the calculations, we investigated the original mechanism proposed by Hillhouse and co-workers for the activation of N2O. The calculations showed that the complex with an initial O-coordination of N2O to the coordinatively unsaturated Hf center is not a local minimum. Then we proposed a new reaction mechanism to investigate how N2O is activated and why N2O selectively oxidize phenyl and hydride ligands of . Frontier molecular orbital theory analysis indicates that N2O is activated by nucleophilic attack by the phenyl or hydride ligand. Present calculations provide new insights into the activation of N2O involving the direct oxygen atom transfer from nitrous oxide to metal-ligand bonds instead of the generally observed oxygen abstraction reaction to generate metal-oxo species.
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Affiliation(s)
- Hujun Xie
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310018, People's Republic of China.
| | - Chengcheng Liu
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310018, People's Republic of China.
| | - Ying Yuan
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310018, People's Republic of China.
| | - Tao Zhou
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310018, People's Republic of China.
| | - Ting Fan
- Division of Theoretical Chemistry and Biology, School of Biotechnology, KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden.
| | - Qunfang Lei
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Wenjun Fang
- Department of Chemistry, Zhejiang University, Hangzhou 310027, People's Republic of China
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11
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Zwettler N, Schachner JA, Belaj F, Mösch-Zanetti NC. Oxorhenium(V) Complexes with Phenolate–Pyrazole Ligands for Olefin Epoxidation Using Hydrogen Peroxide. Inorg Chem 2014; 53:12832-40. [DOI: 10.1021/ic501794z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Niklas Zwettler
- Institute of Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria
| | - Jörg A. Schachner
- Institute of Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria
| | - Ferdinand Belaj
- Institute of Chemistry, University of Graz, Schubertstrasse 1, 8010 Graz, Austria
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12
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Xie H, Yang L, Ye X, Cao Z. Mechanism of Carbon Monoxide Induced N–N Bond Cleavage of Nitrous Oxide Mediated by Molybdenum Complexes: A DFT Study. Organometallics 2014. [DOI: 10.1021/om400935f] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Hujun Xie
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310035, People’s Republic of China
| | - Liu Yang
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310035, People’s Republic of China
| | - Xinchen Ye
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou 310035, People’s Republic of China
| | - Zexing Cao
- State Key Laboratory of Physical Chemistry
of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical
and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China
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13
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Abstract
The dioxomolybdenum(vi) complex ((t)BuClipH2)MoO2 ((t)BuClipH4 = 4,4'-di-tert-butyl-N,N'-bis(3,5-di-tert-butyl-2-hydroxyphenyl)-2,2'-diaminobiphenyl) reacts with 3,5-di-tert-butylcatechol to form oxo-free ((t)BuClip)Mo(3,5-(t)Bu2Cat). The bis(amidophenoxide)-monocatecholate complex is monomeric and exhibits a cis-β geometry in the solid state. Variable-temperature NMR data are consistent with two fluxional processes, one that interconverts several geometric isomers at low temperature, and a second that interchanges the ends of the (t)BuClip ligand at ambient temperatures. The high-temperature fluxional process can be explained by a single Bailar trigonal twist coupled with atropisomerization of the chiral diaminobiaryl backbone. Addition of excess catechol to ((t)BuClipH2)MoO2 results in formation of a dimolybdenum mono-oxo complex ((t)BuClip)Mo(μ-3,5-(t)Bu2Cat)2Mo(O)(3,5-(t)Bu2Cat). This complex, which contains a seven-coordinate bis(amidophenoxide)molybdenum center and a six-coordinate oxomolybdenum center, represents a structural hybrid between dimeric oxomolybdenumbis(catecholate) and molybdenum tris(catecholate) complexes. Both mono- and dimolybdenum complexes are best formulated as containing Mo(vi), but there is structural evidence for significant π donation from the amidophenolates. ((t)BuClip)Mo(3,5-(t)Bu2Cat) binds pyridine to form a mixture of isomeric seven-coordinate adducts. The Lewis acidity of the mixed amidophenoxide-catecholate appears to be lower than its tris(catecholate) or oxobis(amidophenoxide) analogues, which manifests itself principally in relatively slow binding of pyridine to the six-coordinate complex (k = 8 × 10(4) L mol(-1) s(-1) at 0 °C) rather than in the rate of dissociation of pyridine from the seven-coordinate adduct.
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Affiliation(s)
- Sukesh Shekar
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556-5670, USA.
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14
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Smeltz JL, Lilly CP, Boyle PD, Ison EA. The electronic nature of terminal oxo ligands in transition-metal complexes: ambiphilic reactivity of oxorhenium species. J Am Chem Soc 2013; 135:9433-41. [PMID: 23725588 DOI: 10.1021/ja401390v] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The synthesis of the Lewis acid-base adducts of B(C6F5)3 and BF3 with [DAAmRe(O)(X)] DAAm = N,N-bis(2-arylaminoethyl)methylamine; aryl = C6F5 (X = Me, 1, COCH3, 2, Cl, 3) as well as their diamidopyridine (DAP) (DAP=(2,6-bis((mesitylamino)methyl)pyridine) analogues, [DAPRe(O)(X)] (X = Me, 4, Cl, 5, I, 6, and COCH3,7), are described. In these complexes the terminal oxo ligands act as nucleophiles. In addition we also show that stoichiometric reactions between 3 and triarylphosphine (PAr3) result in the formation of triarylphosphine oxide (OPAr3). The electronic dependence of this reaction was studied by comparing the rates of oxygen atom transfer for various para-substituted triaryl phosphines in the presence of CO. From these experiments a reaction constant ρ = -0.29 was obtained from the Hammett plot. This suggests that the oxygen atom transfer reaction is consistent with nucleophilic attack of phosphorus on an electrophilic metal oxo. To the best of our knowledge, these are the first examples of mono-oxo d(2) metal complexes in which the oxo ligand exhibits ambiphilic reactivity.
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Affiliation(s)
- Jessica L Smeltz
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, North Carolina 27695-8204, United States
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15
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Liu S, Senocak A, Smeltz JL, Yang L, Wegenhart B, Yi J, Kenttämaa HI, Ison EA, Abu-Omar MM. Mechanism of MTO-Catalyzed Deoxydehydration of Diols to Alkenes Using Sacrificial Alcohols. Organometallics 2013. [DOI: 10.1021/om400127z] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Shuo Liu
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Aysegul Senocak
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Jessica L. Smeltz
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina
27695, United States
| | - Linan Yang
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Benjamin Wegenhart
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Jing Yi
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Hilkka I. Kenttämaa
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
| | - Elon A. Ison
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina
27695, United States
| | - Mahdi M. Abu-Omar
- Brown Laboratory and Department
of Chemistry, Purdue University, 560 Oval
Drive, West Lafayette, Indiana 47907, United States
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McMullin CL, Pierpont AW, Cundari TR. Complete methane-to-methanol catalytic cycle: A DFT study of oxygen atom transfer from N2O to late-row (MNi, Cu, Zn) β-diketiminate CH activation catalysts. Polyhedron 2013. [DOI: 10.1016/j.poly.2012.07.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Huynh K, Chun CP, Lough AJ, Manners I. Donor-stabilised cations, phosphinamide anions, and unusual oxidative cyclisation products from halogenated phosphoranimines and phosphinimines with a bulky 2,4,6-tri-tert-butylphenyl substituent at nitrogen. Dalton Trans 2011; 40:10576-84. [DOI: 10.1039/c1dt10641d] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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18
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Liu CG, Guan W, Yan LK, Su ZM. Bonding Interactions between Nitrous Oxide (N2O) and Mono-Ruthenium Substituted Keggin-Type Polyoxometalates: Electronic Structures of Ruthenium/N2O Adducts. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000907] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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19
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Crestoni ME, Fornarini S, Lanucara F, Warren JJ, Mayer JM. Probing 'spin-forbidden' oxygen-atom transfer: gas-phase reactions of chromium-porphyrin complexes. J Am Chem Soc 2010; 132:4336-43. [PMID: 20218631 DOI: 10.1021/ja9103638] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Oxygen-atom transfer reactions of metalloporphyrin species play an important role in biochemical and synthetic oxidation reactions. An emerging theme in this chemistry is that spin-state changes can play important roles, and a 'two-state' reactivity model has been extensively applied especially in iron porphyrin systems. Herein we explore the gas-phase oxygen-atom transfer chemistry of meso-tetrakis(pentafluorophenyl)porphyrin (TPFPP) chromium complexes, as well as some other tetradentate macrocyclic ligands. Electrospray ionization in concert with Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry has been used to characterize and observe reactivity of the ionic species [(TPFPP)Cr(III)](+) (1) and [(TPFPP)Cr(V)O](+) (2). These are attractive systems to examine the effects of spin-state change on oxygen-atom transfer because the d(1) Cr(V) species are doublets, while the Cr(III) complexes have quartet ground states with high-lying doublet excited states. In the gas phase, [(TPFPP)Cr(III)](+) forms adducts with a variety of neutral donors, but O-atom transfer is only observed for NO(2). Pyridine N-oxide adducts of 1 do yield 2 upon collision-induced dissociation (CID), but the ethylene oxide, DMSO, and TEMPO analogues do not. [(TPFPP)Cr(V)O](+) is shown by its reactivity and by CID experiments to be a terminal metal-oxo with a single, vacant coordination site. It also displays limited reaction chemistry, being deoxygenated only by the very potent reductant P(OMe)(3). In general, [(TPFPP)Cr(V)O](+) species are much less reactive than the Fe and Mn analogues. Thermochemical analysis of the reactions points toward the involvement of spin issues in the lower observed reactivity of the chromium complexes.
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Affiliation(s)
- Maria Elisa Crestoni
- Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università di Roma La Sapienza, P.le A. Moro 5, I-00185 Roma, Italy.
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20
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Gerber T, Tshentu Z, Mayer P. Synthesis and structural characterization of cationic octahedral oxorhenium(V) complexes with bidentate imidazole derivatives. J COORD CHEM 2010. [DOI: 10.1080/00958970310001617049] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- T.I.A. Gerber
- a Department of Chemistry , University of Port Elizabeth , P.O. Box 1600, Port Elizabeth 6000, South Africa
| | - Z.R. Tshentu
- a Department of Chemistry , University of Port Elizabeth , P.O. Box 1600, Port Elizabeth 6000, South Africa
| | - P. Mayer
- b Department of Chemistry , Ludwig-Maximilians University , D-81377 München, Germany
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21
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Rybak WK, Zagiczek A. Synthesis, Structure and Catalytic Activity of An Oxorhenium(V) Complex Containing Chelating Phosphite Ligand. J COORD CHEM 2009. [DOI: 10.1080/00958979209407915] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Witold K. Rybak
- a Institute of Chemistry, University of Wroclaw , 14 Joliet-Cune str., 50-383 , Wroclaw , Poland
| | - Anna Zagiczek
- a Institute of Chemistry, University of Wroclaw , 14 Joliet-Cune str., 50-383 , Wroclaw , Poland
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22
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Du Preez JGH, Gerber TIA, Kemp HJ. Synthesis and Characterization of Six-Coordinate Cationic Technetium(V) And Rhenium(V) Complexes withN-(2-Oxidophenyl)Salicylideneiminate and Bidentate Aromatic Nitrogen-Donor Ligands. J COORD CHEM 2009. [DOI: 10.1080/00958979209407927] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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23
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Barandov A, Abram U. Heterofunctionalized phosphines derived from (2-formylphenyl)diphenylphosphine and their reactions with oxorhenium(V) complexes. Polyhedron 2009. [DOI: 10.1016/j.poly.2009.01.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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24
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Yu H, Jia G, Lin Z. O-Abstraction Reactions of Nitrous Oxide with Cp2Ti(II) and Other Middle Transition Metal Complexes. Organometallics 2009. [DOI: 10.1021/om800897s] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Haizhu Yu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Guochen Jia
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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25
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Oguadinma PO, Schaper F. Syntheses and structures of bis(2,6-xylyl-nacnac) copper(I) complexes. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.05.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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26
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Yu H, Jia G, Lin Z. Theoretical Studies on O-Insertion Reactions of Nitrous Oxide with Ruthenium Hydride Complexes. Organometallics 2008. [DOI: 10.1021/om8000845] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Haizhu Yu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
| | - Guochen Jia
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, Peopleʼs Republic of China
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27
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Yu H, Jia G, Lin Z. DFT Studies on the Mechanism of Reactions between N2O and Cp2M(η2-alkyne) (M = Ti, Zr). Organometallics 2007. [DOI: 10.1021/om7010134] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Haizhu Yu
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Guochen Jia
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Zhenyang Lin
- Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
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28
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Zdilla MJ, Dexheimer JL, Abu-Omar MM. Hydrogen Atom Transfer Reactions of Imido Manganese(V) Corrole: One Reaction with Two Mechanistic Pathways. J Am Chem Soc 2007; 129:11505-11. [PMID: 17718564 DOI: 10.1021/ja073027s] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hydrogen atom transfer (HAT) reactions of (tpfc)MnNTs have been investigated (tpfc = 5,10,15-tris(pentafluorophenyl)corrole and Ts = p-toluenesulfonate). 9,10-Dihydroanthracene and 1,4-dihydrobenzene reduce (tpfc)MnNTs via HAT with second-order rate constants 0.16 +/- 0.03 and 0.17 +/- 0.01 M(-1) s(-1), respectively, at 22 degrees C. The products are the respective arenes, TsNH(2) and (tpfc)Mn(III). Conversion of (tpfc)MnNTs to (tpfc)Mn by reaction with dihydroanthracene exhibits isosbestic behavior, and formation of 9,9',10,10'-tetrahydrobianthracene is not observed, suggesting that the intermediate anthracene radical rebounds in a second fast step without accumulation of a Mn(IV) intermediate. The imido complex (tpfc)Mn(V)NTs abstracts a hydrogen atom from phenols as well. For example, 2,6-di-tert-butyl phenol is oxidized to the corresponding phenoxyl radical with a second-order rate constant of 0.32 +/- 0.02 M(-1) s(-1) at 22 degrees C. The other products from imido manganese(V) are TsNH(2) and the trivalent manganese corrole. Unlike reaction with dihydroarenes, when phenols are used isosbestic behavior is not observed, and formation of (tpfc)Mn(IV)(NHTs) is confirmed by EPR spectroscopy. A Hammett plot for various p-substituted 2,6-di-tert-butyl phenols yields a V-shaped dependence on sigma, with electron-donating substituents exhibiting the expected negative rho while electron-withdrawing substituents fall above the linear fit (i.e., positive rho). Similarly, a bond dissociation enthalpy (BDE) correlation places electron-withdrawing substituents above the well-defined negative slope found for the electron-donating substituents. Thus two mechanisms are established for HAT reactions in this system, namely, concerted proton-electron transfer and proton-gated electron transfer in which proton transfer is followed by electron transfer.
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Affiliation(s)
- Michael J Zdilla
- Brown Laboratory, Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA
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29
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Walstrom A, Pink M, Fan H, Tomaszewski J, Caulton KG. Radical (NO) and nonradical (N(2)O) reagents convert a ruthenium(IV) nitride to the same nitrosyl complex. Inorg Chem 2007; 46:7704-6. [PMID: 17705469 DOI: 10.1021/ic700789y] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The ruthenium(IV) nitride complex (PNP)RuN (PNP = (tBu2PCH2-SiMe2)2N-) reacts rapidly with 2NO to form (PNP)Ru(NO) and N2O, via no detectable intermediate. The linear nitrosyl complex has a planar structure. In a slower reaction, (PNP)RuN reacts with N2O by O-atom transfer (established by 15N labeling) to give the same nitrosyl complex and N2. Density functional theory (B3LYP) calculations show both reactions to be very thermodynamically favorable. Analysis of possible intermediates in each reaction shows that radical (PNP)RuN(NO) has much spin density on nitride N (hence, N2-), while one 2 + 3 metallacycle, (PNP)RuN3O, has the wrong connectivity to form a product. Instead, an intermediate with a doubly bent N2O (hence, a two-electron reduced N-nitrosoimide form) brings the O atom in proximity to the nitride N on the path to a product.
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Affiliation(s)
- Amy Walstrom
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
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30
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Abstract
[NBu4][TcOCl4] reacts with ethylene glycol and 1,4,7-triazacyclononane (tacn) in MeOH under the formation of the deep-blue oxotechnetium(V) cation [TcO(OC2H4O)(tacn)]+, which can readily be oxidized by air to give the stable technetium(VII) compound [TcO3(tacn)]+. The reaction with aqueous HCl results in reduction and the formation of the cationic technetium(III) complex [TcCl2(OH2)(tacn)]Cl. The products were isolated in crystalline form and studied spectroscopically and by X-ray diffraction.
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Affiliation(s)
- Henrik Braband
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Fabeckstrasse 34-36, D-14195 Berlin, Germany
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31
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Cheng M, Bakac A. Kinetics and mechanism of the reaction of Cr(ii) aqua ions with benzoylpyridine N-oxide. Dalton Trans 2007:2077-82. [PMID: 17502942 DOI: 10.1039/b701236e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Aqueous chromium(II) ions, Cr(aq)(2+), react with benzoylpyridine oxide (BPO) much more rapidly than with other pyridine N-oxides previously explored. The kinetics were studied under pseudo-first order conditions with either reagent in excess. Under both sets of conditions, the major kinetic term exhibits first order dependence on limiting reagent, and second order dependence on excess reagent, i.e.k(Cr) = k2(Cr)[BPO][Cr(aq)(2+)]2 (excess Cr(aq)(2+)), and k(BPO) = k2(BPO)[Cr(aq)(2+)][BPO](2) (excess BPO), where k2(Cr) = (6.90 +/- 0.27) x 10(4) M(-2) s(-1) and k2(BPO) = (3.32 +/- 0.28) x 10(5) M(-2) s(-1) in 0.10 M HClO4. The rate constant k2(Cr) contains terms corresponding to [H+]-independent and [H+]-catalyzed paths. In the proposed mechanism, the initially formed Cr(aq)(BPO)(2+) engages in parallel oxidation of Cr(aq)(2+) and reduction of BPO. The latter reaction provides the basis for a convenient new preparative route for the BPO complex of Cr(III).
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Affiliation(s)
- Mingming Cheng
- Department of Chemistry, Iowa State University, Ames, IA 50011, USA
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32
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Kotowski M, Marcec R, Butkovic V, Bakac A, Orhanovic M. Preparation, Characterization, and Aquation Kinetics of Pyridine
N
‐Oxide Complexes of Chromium(III). Eur J Inorg Chem 2006. [DOI: 10.1002/ejic.200600260] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Mirjana Kotowski
- Rugjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
- Current address: Max Planck Institute for Chemistry, 55128 Mainz, Germany
| | - Radovan Marcec
- Rugjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - Vjera Butkovic
- Rugjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
| | - Andreja Bakac
- Iowa State University, Chemistry Department, Ames, IA 50011, Iowa, USA
| | - Matko Orhanovic
- Rugjer Boskovic Institute, Bijenicka 54, 10000 Zagreb, Croatia
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33
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Chakravorty A. Variable‐Valent Rhenium Chemistry of Conjugated Nitrogenous Ligands: Structure and Reactivity. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200500615] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Animesh Chakravorty
- Department of Inorganic Chemistry, Indian Association for the Cultivation of Science, Kolkata 700032, India
- Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore 560064, India
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34
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Mosch-Zanetti NC, Sachse A, Pfoh R, Vidovic D, Magull J. Rhenium oxo compounds containing eta2-pyrazolate ligands. Dalton Trans 2005:2124-9. [PMID: 15957054 DOI: 10.1039/b501025j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Reaction of potassium salts of sterically demanding pyrazolates (pz = bis-3,5-tert-butylpyrazolate, pz= bis-3,5-tert-butyl-4-methylpyrazolate) with Re2O7 affords soluble eta2-pyrazolate complexes of the type [(eta2-pz)ReO3(THF)n](1: pz, n= 1 and 2: pz, n= 0). They were characterized by spectroscopic methods and by X-ray crystallography confirming the eta2-coordinate ligands. Complex 1 employing the ligand with a proton in the 4-position retains one molecule of THF, whereas the additional methyl group in 2 leads to the base-free compound 2. Compound 1 reacts with pyridine and 3,5-dimethylpyridine to form Lewis base adducts of the type [(eta2-pz)ReO3(L)](3: L = py; 4: L = 3,5-Me2py). The pronounced sensitivity towards water of these complexes is demonstrated by the reaction of 1 with one equivalent of water forming the corresponding pyrazolium perrhenate [ReO4][pzH2](5). Its solid state structure shows a hydrogen bonded dimeric assembly. Catalytic activity of 1 is established in oxygen atom transfer-reactions (OAT) from dimethylsulfoxide to triphenylphosphine, and in epoxidations of cyclooctene employing bis(trimethylsilyl) peroxide (BTSP).
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Affiliation(s)
- Nadia C Mosch-Zanetti
- Institut fur Anorganische Chemie, Georg-August-Universitat Gottingen, Tammannstrasse 4, D-37077 Gottingen, Germany.
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35
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Mashaly MM, El-Shafiy HF, El-Maraghy SB, Habib HA. Synthesis, properties and thermal studies of oxorhenium(V) complexes with 3-hydrazino-5,6-diphenyl-1,2,4-triazine, benzimidazolethione and 2-hydrazinobenzimidazole. Mixed ligand complexes, pyrolytical products and biological activity. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2005; 61:1853-1869. [PMID: 15863057 DOI: 10.1016/j.saa.2004.06.056] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2004] [Accepted: 06/08/2004] [Indexed: 05/24/2023]
Abstract
A series of biologically active complexes of oxorhenium(V), were prepared by using the organic ligands 3-hydrazino-5,6-diphenyl-1,2,4-triazine (HL1), benzimidazolethione (H2L2) and 2-hydrazinobenzimidazole (H2L3). The mixed ligand complexes of oxorhenium(V) with the previous ligands and one of the following ligands: NH4SCN, 1,10-phenanthroline (1,10-phen), 8-hydroxyquinoline (8-OHquin) or glycine (Gly), were isolated. All the binary and mixed ligand complexes have monomeric structures and exist in the octahedral configuration. Thermal studies on these complexes showed the possibility of structural transformation from mononuclear into binuclear ones. The structures of all complexes and the corresponding thermal products were elucidated by elemental analyses, IR, electronic absorption and 1H NMR spectra, magnetic moments, conductance and TG-DSC measurements. The antifungal activities of the metal complexes towards Alternaria alternata and Aspergilus niger were tested and showed comparable behaviour with some well known antibiotics.
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Affiliation(s)
- M M Mashaly
- Department of Chemistry, Faculty of Education, Ain Shams University, Roxy, Cairo, Egypt.
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36
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The reactivity of [ReBr3(MeCN)(dppe)] towards gaseous nitric oxide. The X-ray structure of [ReBr3(MeCN)(dppe)] and [ReBr3(NO)(dppe)]0.57[ReOBr3(dppe)]0.43 and DFT calculations for [ReBr3(NO)(dppe)] and [ReOBr3(dppe)]. J Mol Struct 2005. [DOI: 10.1016/j.molstruc.2005.01.038] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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37
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Wei L, Babich J, Zubieta J. Complexes of the {ReVOX2}+ (X=Cl, Br) core with single amino acid chelate derivatives. Inorganica Chim Acta 2005. [DOI: 10.1016/j.ica.2005.01.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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38
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Nabavizadeh SM, Akbari A, Rashidi M. Solvent effect on the adduct formation of methyltrioxorhenium (MTO) and pyridine: enthalpy and entropy contributions. Dalton Trans 2005:2423-7. [PMID: 15995752 DOI: 10.1039/b503870g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
1:1 adduct formation between methyltrioxorhenium (MTO) and pyridine in different solvents (n-hexane, benzene, chloroform, ethyl acetate, dichloromethane and acetone) was studied using spectrophotometric techniques. The formation constants were determined from the absorbance change of the adduct versus pyridine concentration. The values of the formation constants vary from 114.5 to 752.5 L mol(-1) at T= 20 degrees C depending on the dielectric constant of the solvent (epsilon(r) = 1.89-20.7). Enthalpy and entropy changes during the adduct formation reactions were determined from van't Hoff plots. The measured enthalpy change of -37.0 to -22.2 kJ mol(-1) depends on epsilon(r), which is explained by Onsager's reaction field theory. The measured entropy change ranges from -71.2 to -36.6 J K(-1) mol(-1), and the dependence on the solvent is discussed in terms of the solvation effect.
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Affiliation(s)
- S Masoud Nabavizadeh
- Department of Chemistry, College of Sciences, Shiraz University, Shiraz, Iran 71454.
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39
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Xavier C, Paulo A, Domingos A, Santos I. Synthesis and Structural Studies of Rhenium(V) Complexes Stabilized by a Monoanionic Cyclen Ligand. Eur J Inorg Chem 2004. [DOI: 10.1002/ejic.200300490] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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40
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Baril-Robert F, Beauchamp AL. Preparation and electronic properties of rhenium(V) complexes with bis(diphenyl phosphino)ethane. CAN J CHEM 2003. [DOI: 10.1139/v03-143] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Complexes of bis(diphenylphosphino)ethane (dppe) of the types ReOX3(dppe) and ReO(OR)X2(dppe) (with X= Cl or Br, and R = Me, Et, Pr, Ph, cyclohexyl (Cy), or -CH2CH2OH) were prepared to evaluate the influence of ligand changes on the low-energy dd transitions in these Re(V) low-spin d2 systems. Arylimido compounds Re(NR)Cl3(dppe) (with R = Ph and p-ClC6H4) were also obtained. X-ray diffraction studies on ReO(OPr)Cl2(dppe), ReO(OPh)Br2(dppe), and ReO(OCy)Cl2(dppe) confirmed the presence of the trans O=Re-OR unit and showed that the structural characteristics of the Re-O-R segment are not affected by the presence of a bulky cyclohexyl substituent or an aromatic phenyl group. The structure of the arylimido complex Re(p-ClC6H4N)Cl3(dppe) was also determined. The electronic absorption spectra of the ReOX3(dppe) compounds include two low-energy components at ~11 500 and ~16 000 cm1, assigned to the two spin-allowed dd transitions expected for these low-symmetry systems. Substitution of the oxo ligand by an arylimido group has little effect on the lower-energy component, but moves the two components closer together. Replacing the halogen trans to the Re=O bond by an alkoxo group shifts the whole system to higher energies. These variations were found to correlate well with the energies of the frontier orbitals determined from DFT calculations. While attempting to prepare ReOCl3(dppe) from ReOCl3(PPh3)2, the Re(III) compound fac-ReCl3(PPh3){Ph2PC2H4PPh2(O)} was obtained, in which one end of dppe had become a phosphine oxide. Upon standing in DMSO, this compound gave the octahedral compound ReCl4{Ph2PC2H4PPh2(O)}, in which the formation of a chelate ring involving a phosphine and a phosphine oxide was ascertained by X-ray diffraction.Key words: rhenium, crystal structure, DFT calculations, dd electron transitions.
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41
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The synthesis, spectroscopic investigation, crystal and molecular structure of [ReCl3(MeCN)(dppe)] complex. INORG CHEM COMMUN 2003. [DOI: 10.1016/s1387-7003(03)00107-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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42
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Garcia R, Xing YH, Domingos Â, Paulo A, Santos I. Rhenium oxocomplexes with the heteroscorpionate phenyltris(pyrazolyl)borate: synthesis and structural studies. Inorganica Chim Acta 2003. [DOI: 10.1016/s0020-1693(02)01184-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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43
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Ozerov OV, Gerard HF, Watson LA, Huffman JC, Caulton KG. Double silyl migration converting ORe[N(SiMe(2)CH(2)PCy(2))(2)] to NRe[O(SiMe(2)CH(2)PCy(2))(2)] substructures. Inorg Chem 2002; 41:5615-25. [PMID: 12377062 DOI: 10.1021/ic020424p] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The reaction of (R(2)PCH(2)SiMe(2))(2)NM (PNP(R)M; R = Cy; M = Li, Na, MgHal, Ag) with L(2)ReOX(3) [L(2) = (Ph(3)P)(2) or (Ph(3)PO)(Me(2)S); X = Cl, Br] gives (PNP(Cy))ReOX(2) as two isomers, mer,trans and mer,cis. These compounds undergo a double Si migration from N to O at 90 degrees C to form (POP(Cy))ReNX(2) as a mixture of mer,trans and fac,cis isomers. Additional thermolysis effects migration of CH(3) from Si to Re, along with compensating migration of halide from Re to Si. DFT calculations on various structural isomers support the greater thermodynamic stability of the POP/ReN isomer vs PNP/ReO and highlight the influence of the template effect on the reactivities of these species.
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Affiliation(s)
- Oleg V Ozerov
- Department of Chemistry and Molecular Structure Center, Indiana University, Bloomington, IN 47405, USA
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44
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Jacobi BG, Laitar DS, Pu L, Wargocki MF, DiPasquale AG, Fortner KC, Schuck SM, Brown SN. Stoichiometric and catalytic oxygen activation by trimesityliridium(III). Inorg Chem 2002; 41:4815-23. [PMID: 12206710 DOI: 10.1021/ic025700e] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Trimesityliridium(III) (mesityl = 2,4,6-trimethylphenyl) reacts with O(2) to form oxotrimesityliridium(V), (mes)(3)Ir=O, in a reaction that is cleanly second order in iridium. In contrast to initial reports by Wilkinson, there is no evidence for substantial accumulation of an intermediate in this reaction. The oxo complex (mes)(3)Ir=O oxidizes triphenylphosphine to triphenylphosphine oxide in a second-order reaction with DeltaH++ = 10.04 +/- 0.16 kcal/mol and DeltaS++ = -21.6 +/- 0.5 cal/(mol.K) in 1,2-dichloroethane. Triphenylarsine is also oxidized, though over an order of magnitude more slowly. Ir(mes)(3) binds PPh(3) reversibly (K(assoc) = 84 +/- 3 M(-1) in toluene at 20 degrees C) to form an unsymmetrical, sawhorse-shaped four-coordinate complex, whose temperature-dependent NMR spectra reveal a variety of dynamic processes. Oxygen atom transfer from (mes)(3)Ir=O and dioxygen activation by (mes)(3)Ir can be combined to allow catalytic aerobic oxidations of triphenylphosphine at room temperature and atmospheric pressure with overall activity (approximately 60 turnovers/h) comparable to the fastest reported catalysts. A kinetic model that uses the rates measured for dioxygen activation, atom transfer, and phosphine binding describes the observed catalytic behavior well. Oxotrimesityliridium does not react with sulfides, sulfoxides, alcohols, or alkenes, apparently for kinetic reasons.
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Affiliation(s)
- Bridey Grant Jacobi
- Department of Chemistry and Biochemistry, 251 Nieuwland Science Hall, University of Notre Dame, Notre Dame, IN 46556-5670, USA
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45
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Ben-Daniel R, Weiner L, Neumann R. Activation of nitrous oxide and selective epoxidation of alkenes catalyzed by the manganese-substituted polyoxometalate, [Mn(III)2ZnW(Zn2W9O34)2]10-. J Am Chem Soc 2002; 124:8788-9. [PMID: 12137519 DOI: 10.1021/ja0259077] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A manganese(III)-substituted polyoxometalate of the "sandwich" structure, [MnIII2ZnW(ZnW9O34)2]10-, catalyzed the highly selective (>99.9%) epoxidation of alkenes, such as 1-octene, 2-octene, and cyclohexene with nitrous oxide. Reactions occurred in homogeneous media at 150 degrees C under 1 atm N2O. The epoxidation had a linear reaction profile; turnover frequencies of 0.5-1.4 h-1 were measured. The reactions were also stereoselective; for example, cis-stilbene gave cis-stilbene oxide. From ESR spectroscopy, it was shown that a Mn(II) octahedral species is reversibly formed by reaction between the original Mn(III) polyoxometalate and N2O. Therefore, it would appear that a Mn(V)-oxo active species is not formed; it is possible that the activation of nitrous oxide was by its oxidation by the Mn(III) polyoxometalate.
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Affiliation(s)
- Revital Ben-Daniel
- Department of Organic Chemistry and Chemical Services Division, Weizmann Institute of Science, Rehovot, Israel 76100
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46
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Béreau VM, Khan SI, Abu-Omar MM. Synthesis of enantiopure oxorhenium(V) and arylimidorhenium(V) "3 + 2" Schiff base complexes. X-ray diffraction, cyclic voltammetry, UV-vis, and circular dichroism characterizations. Inorg Chem 2001; 40:6767-73. [PMID: 11735489 DOI: 10.1021/ic0108033] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Two new oxorhenium(V) and two new arylimidorhenium(V) complexes of the Schiff base ligands 2-hydroxybenzaldehyde-((1R,2S)-1-amino-2-indanol)imine (1) (H(2)L(1)) and 3-(1-adamantyl)-2-hydroxy-5-methylbenzaldehyde-((1R,2S)-1-amino- 2-indanol)imine (2) (H(2)L(2)) have been prepared from the reaction of the precursor Re(O)(PPh(3))(2)Cl(3), Re(NC(6)H(5))(PPh(3))(2)Cl(3), or Re(NC(6)H(4)OCH(3))(PPh(3))(2)Cl(3) and the free ligands H(2)L(1,2). The complexes Re(O)(HL(1))(L(1)) (3), Re(O)(HL(2))(L(2)) (4), Re(NC(6)H(5))(HL(1))(L(1)) (5), and Re(NC(6)H(4)OCH(3))(HL(1))(L(1)) (6) have been isolated and fully characterized by IR, (1)H NMR, circular dichroism, LRMS-FAB, and elemental analysis. All the complexes have a chiral center at rhenium. A single enantiomer is obtained in all cases. Suitable crystals of 3 and 5 were used in X-ray structural determinations. Crystal data: (3) C(32)H(27)N(2)O(5)Re.CH(2)Cl(2), orthorhombic, P2(1)2(1)2(1), a = 9.5599(16) A, b = 9.9579(16) A, c = 31.712(5) A, V = 3018.9(9) A(3), T = 100(2) K, Z = 4. (5) C(40)H(38)N(3)O(5)Re, monoclinic, P2(1), a = 9.286(3) A, b = 18.759(6) A, c = 9.957(3) A, beta = 102.817(6) degrees, V = 1691.3(10) A(3), T = 100(2) K, Z = 2. The major characteristic of these complexes is the presence of two coordination modes for the Schiff base ligands on rhenium, a tridentate ligand (noted L(1,2)) and another bidentate ligand (noted HL(1,2)). In the latter, the -OH group of the indanol is free and tilts away from the coordination sphere. X-ray structural analyses in conjunction with circular dichroism were used to assign the absolute configuration at rhenium (C). Cyclic voltammetry, UV-vis, and circular dichroism data are presented and discussed. The complexes were found to be highly stable and to resist reduction even when treated with organic phosphanes.
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Affiliation(s)
- V M Béreau
- Department of Chemistry and Biochemistry, University of California, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA
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Synthesis, crystal and molecular structure, spectroscopic and electrochemical studies of trichloro-oxo(4,6-dimethylpyrimidine-2(1H)-thione)(triphenylphosphine oxide)rhenium(V) complex. Inorganica Chim Acta 2001. [DOI: 10.1016/s0020-1693(01)00478-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Arias J, Newlands CR, Abu-Omar MM. Kinetics and mechanisms of catalytic oxygen atom transfer with oxorhenium(V) oxazoline complexes. Inorg Chem 2001; 40:2185-92. [PMID: 11304165 DOI: 10.1021/ic000917z] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rhenium(V) monooxo complexes (hoz)2Re(O)Cl (1) and [(hoz)2Re(O)(OH2)][OTf] (2) have been synthesized and fully characterized (hoz = 2-(2'-hydroxyphenyl)-2-oxazoline). A single-crystal X-ray structure of 2 has been solved: space group = P1, a = 13.61(2) A, b = 14.76(2) A, c = 11.871(14) A, alpha = 93.69(4) degrees, beta = 99.43(4) degrees, gamma = 108.44(4) degrees, Z = 4; the structure was refined to final residuals R = 0.0455 and Rw = 0.1055. 1 and 2 catalyze oxygen atom transfer from aryl sulfoxides to alkyl sulfides and oxygen-scrambling between sulfoxides to yield sulfone and sulfide. Superior catalytic activity has been observed for 2 due to the availability of a coordination site on the rhenium. The active form of the catalyst is a dioxo rhenium(VII) intermediate, [Re(O)2(hoz)2]+ (3). In the presence of sulfide, 3 is rapidly reduced to [Re(O)(hoz)2]+ with sulfoxide as the sole organic product. The transition state is very sensitive to electronic influences. A Hammett correlation plot with para-substituted thioanisole derivatives gave a reaction constant rho of -4.6 +/- 0.4, in agreement with an electrophilic oxygen transfer from rhenium. The catalytic reaction features inhibition by sulfides at high concentrations. The equilibrium constants for sulfide binding to complex 2 (cause of inhibition), K2 (L x mol(-1)), were determined for a few sulfides: Me2S (22 +/- 3), Et2S (14 +/- 2), and tBu2S (8 +/- 2). Thermodynamic data, obtained from equilibrium measurements in solution, show that the S=O bond in alkyl sulfoxides is stronger than in aryl sulfoxides. The Re=O bond strength in 3 was estimated to be about 20 kcal x mol(-1). The high activity and oxygen electrophilicity of complex 3 are discussed and related to analogous molybdenum systems.
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Affiliation(s)
- J Arias
- Department of Chemistry and Biochemistry, University of California, Los Angeles, 405 Hilgard Avenue, Los Angeles, California 90095-1569, USA
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Huang R, Espenson JH. Mechanistic Study of Oxygen-Transfer Reaction Catalyzed by an Oxorhenium(V) Compound. Inorg Chem 2001. [DOI: 10.1021/ic000854k] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Ruili Huang
- Ames Laboratory and the Department of Chemistry, Iowa State University of Science and Technology, Ames, Iowa 50011
| | - James H. Espenson
- Ames Laboratory and the Department of Chemistry, Iowa State University of Science and Technology, Ames, Iowa 50011
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