Studies on Synthesis, Properties and Reactions of High-valent Oxo Molybdenum and Tungsten Complexes

Studies on Synthesis, Properties and Reactions of High-valent Oxo Molybdenum and Tungsten Complexes PDF Author: Fu-Min Su
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ISBN:
Category : Metallic oxides
Languages : en
Pages : 166

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Studies on Synthesis, Properties and Reactions of High-valent Oxo Molybdenum and Tungsten Complexes

Studies on Synthesis, Properties and Reactions of High-valent Oxo Molybdenum and Tungsten Complexes PDF Author: Fu-Min Su
Publisher:
ISBN:
Category : Metallic oxides
Languages : en
Pages : 166

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Synthesis and Studies of Mo and W Complexes for 2N Reduction

Synthesis and Studies of Mo and W Complexes for 2N Reduction PDF Author: Jia Min Chin
Publisher:
ISBN:
Category :
Languages : en
Pages : 188

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A series of monopyrroletriamine ligands [Arpyr(Ar')2]H3 of the form ArC4H2NHCH2N(CH2CH2NHAr')2 (Ar = 2,4,6-mesityl (Mes), 2,4,6-triisopropylphenyl (TRIP); Ar' = C6F5, 2-tolyl (o-tol), naphthyl, 3,5-(2,4,6-triisopropylphenyl)phenyl (HIPT), 3,5- dimethylphenyl, 3,5-di-tert-butylphenyl were synthesized. [Mespyr(C6F5)2]MoCl, ([Mespyr(C6F5)2]Mo = MesitylC4H2NCH2N(CH2CH2NC6F5)2) was prepared by reaction of [Mespyr(C6F5)2]H3 with MoCl4(THF)2 and base and [Mespyr(3,5-t-Bu)2]MoCl and [Mespyr(3,5- Me)2]MoCl (3,5-t-Bu=3,5-di-tert-butylphenyl, Me = 3,5-dimethylphenyl) were synthesized likewise. All three monochlorides are paramagnetic. [Mespyr(C6F5)2]MoNMe2, [[Mespyr(otol) 2]MoNMe2, [Mespyr(3,5-t-Bu)2]MoNMe2, [Mespyr(3,5-Me)2]MoNMe2 were synthesized by reaction of the ligands with Mo(NMe2)4. The resulting compounds are diamagnetic and range in color from teal blue to emerald green. These low spin monodimethylamide complexes exist in rapid equilibria with their high spin forms. [Mespyr(C6F5)2]MoN and [Mespyr(3,5-t-Bu)2]MoN were synthesized by reaction of their respective monochlorides with NaN3 and are yellow diamagnetic species. Reaction of [Mespyr(3,5-t-Bu)2]MoN with Et3OBF4 leads to {[Mespyr(3,5- t-Bu)2]MoNEt}BF4, also a diamagnetic yellow species. [Mespyr(C6F5)2]MoOTf is synthesized by the reaction of [Mespyr(C6F5)2]MoCl with AgOTf. Reduction of [Mespyr(3,5-t-Bu)2]MoCl with Na under N2 led to [Mespyr(3,5-t-Bu)2]MoNNNa(THF)x, several species with varying numbers of THF coordination, x. A single species can be obtained when [Mespyr(3,5-t- Bu)2]MoNNNa(THF)x is reacted with either NBu4Cl or 15-crown-5 ether to yield purple green 4 {[Mespyr(3,5-t-Bu)2]MoNN}NBu4 or [Mespyr(3,5-t-Bu)2]MoNNNa(15-c-5). All the diazenide species are diamagnetic. Oxidation of the diazenide with AgOTf yields [Mespyr(3,5-t- Bu)2]Mo(N2). [Mespyr(3,5-t-Bu)2]Mo(CO) is synthesized by exposure of [Mespyr(3,5-t- Bu)2]Mo(N2) to CO. Reaction of [Mespyr(3,5-t-Bu)2]MoCl with NaBPh4 and NH3 yields {[Mespyr(3,5-t-Bu)2]Mo(NH3)}BPh4. Catalytic runs employing [Mespyr(3,5-t-Bu)2]MoN as the catalyst yielded one equivalent of NH3. A triamidoamine ligand [(HIPTNCH2CH2CH2)3N]3- was synthesized and metalated with MoCl4(THF)2 to produce [(HIPTNCH2CH2CH2)3N]MoCl ([HIPTtrpn]MoCl). Reduction of [HIPTtrpn]MoCl by KC8 under an atmosphere of dinitrogen leads to the green species [HIPTtrpn]MoNNK which can be oxidized by ZnCl2(dioxane) to produce [HIPTtrpn]Mo(N2). Other complexes synthesized include {[HIPTtrpn]Mo(NH3)}+ salts and [HIPTtrpn]Mo(CO). Xray studies were carried out on [HIPTtrpn]MoN and {[HIPTtrpn]Mo(NH3)}BAr'4. This system is not catalytic for the reduction of dinitrogen to ammonia and studies were carried out to elucidate the reasons. Oxidation studies were carried out on [HIPTN3N]Mo(N2) and [HIPTN3N]W(N2) ([HIPTN3N] = [(HIPTNCH2CH2)3N]3- ). The rate of conversion of [HIPTN3N]Mo(NH3) to [HIPTN3N]Mo(N2) was studied and found to be increased in the presence of BPh3. [HIPTN3N]Mo(N2) conversion to [HIPTN3N]Mo(CO) was found to be dependent on CO pressure. Protonation studies of [HIPTN3N]Mo(N2) were also carried out. Studies of [HIPTN3N]MoNNH decomposition showed that decomposition is not base-catalyzed. [HIPTN3N]W(CO) was synthesized by exposure of [HIPTN3N]W(N2) to CO. It is a green, paramagnetic compound and its use as a standard (for determining relative concentrations of other compounds in the IR sample) in IR spectroscopic studies appears to be promising. [HIPTN3N]MoCNH2 was synthesized by addition of acid and reducing agent to [HIPTN3N]MoCN and is a yellow, diamagnetic compound. Two triamidophosphine ligands, triHIPTamine and tri-n-Buamine were synthesized. Metalation of Zr(NMe2)4 with these ligands leads to formation of pn3HIPTZrNMe2 and pn3-n- BuZrNMe2, both diamagnetic, pale yellow complexes.

Oxo Complexes of Tungstenocene Via Oxidation of (W(Eta(5)-C5H5)2(OCH3) (CH3)) and Related Reactions: Synthesis, Structural Characterization, and Photodisproportionation of the Spin Paired D(1)-d(1) Oxo Bridged Dimer ((W(Eta(5)-C5H5)2(CH3))2(Mu-O))2(+) and Synthesis and Charaterization of the D(0) Terminal Oxo Complex (W(Eta(5)-C5H5)2(O)(CH3))(+).

Oxo Complexes of Tungstenocene Via Oxidation of (W(Eta(5)-C5H5)2(OCH3) (CH3)) and Related Reactions: Synthesis, Structural Characterization, and Photodisproportionation of the Spin Paired D(1)-d(1) Oxo Bridged Dimer ((W(Eta(5)-C5H5)2(CH3))2(Mu-O))2(+) and Synthesis and Charaterization of the D(0) Terminal Oxo Complex (W(Eta(5)-C5H5)2(O)(CH3))(+). PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 52

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There has been remarkable growth throughout the 1980s in the chemistry of transition metal oxo complexes. Interest in what had been regarded as a mature area was rekindled in part by the recognition of the role of the oxo functionality as a 'spectator' ligand in catalytic alkene metathesis, and has been fueled by developments in the chemistry of transition metal porphyrin oxo complexes (including their roles in hydrocarbon oxidations and in alkene epoxidation and hydroxylation reactions), by continuing rapid evolution of our understanding of biologically relevent oxo transfer reactions, by extraordinary advances in the use of oxo complexes as catalysts for alkene hydroxylation and epoxidation, and most recently, by the remarkable catalystic activity demonstrated by high valent rehenium oxo alkyls. These development have been paralleled by significant advances in the syntheses of oxo complexes, including the preparations of 'low valent' oxo complexes and of high valent oxo alkyl complexes, and marked extentions of the rational synthesis of organometallic oxo complexes.

Aspects of High-valent Oxo Chemistry of Molybdenum and Tungsten

Aspects of High-valent Oxo Chemistry of Molybdenum and Tungsten PDF Author: Andrew John Millar
Publisher:
ISBN:
Category : Calixarenes
Languages : en
Pages : 544

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Synthesis, Properties and Structural Characterization of Novel Oxo, Nitrido Molybdenum Compounds with Alkoxy and Siloxy Ligands

Synthesis, Properties and Structural Characterization of Novel Oxo, Nitrido Molybdenum Compounds with Alkoxy and Siloxy Ligands PDF Author: Gyu Shik Kim
Publisher:
ISBN:
Category : Molybdenum compounds
Languages : en
Pages : 392

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Dissertation Abstracts International

Dissertation Abstracts International PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 846

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Synthesis and Reactivity of Molybdenum and Tungsten Bis-tri-tert-butylsiloxide Imido and Oxo Complexes

Synthesis and Reactivity of Molybdenum and Tungsten Bis-tri-tert-butylsiloxide Imido and Oxo Complexes PDF Author: Devon Charles Rosenfeld
Publisher:
ISBN:
Category :
Languages : en
Pages : 402

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Index to American Doctoral Dissertations

Index to American Doctoral Dissertations PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 1252

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Comprehensive Dissertation Index

Comprehensive Dissertation Index PDF Author:
Publisher:
ISBN:
Category : Dissertations, Academic
Languages : en
Pages : 712

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Molybdenum and Molybdenum-Containing Enzymes

Molybdenum and Molybdenum-Containing Enzymes PDF Author: Michael P. Coughlan
Publisher: Elsevier
ISBN: 1483189120
Category : Science
Languages : en
Pages : 590

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Book Description
Molybdenum and Molybdenum-Containing Enzymes is a collection of papers that deals with the various concerns with molybdenum-containing enzymes. The text first covers the organometallic chemistry of molybdenum, and then proceeds to tackling molybdenum-containing enzymes, such as xanthine oxidase, aldehyde oxidase, and sulphite oxidase. The text also discusses the advancement in the understanding of molybdenum-containing enzymes. The remaining chapters deal with the genetics of molybdoenzymes and the nutritional aspects of molybdenum. The book will be of great use to students, researchers, and practitioners of biochemistry.