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Book Synthesis and Characterization of Molybdenum tin Complexes Derived from the Molybdenum Tricarbonyl Anion MeGapz3 Mo CO 3 and Organotin Chlorides X ray Crystal Structure of MeGapz3 Mo CO 3SnPh3 where Pz

Download or read book Synthesis and Characterization of Molybdenum tin Complexes Derived from the Molybdenum Tricarbonyl Anion MeGapz3 Mo CO 3 and Organotin Chlorides X ray Crystal Structure of MeGapz3 Mo CO 3SnPh3 where Pz written by Emmanuel C. Onyiriuka and published by . This book was released on 1986 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Canadian Journal of Chemistry

Download or read book Canadian Journal of Chemistry written by and published by . This book was released on 1986 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book American Chemical Society Directory of Graduate Research 1987

Download or read book American Chemical Society Directory of Graduate Research 1987 written by American Chemical Society, Committee on Professional Training Staff and published by . This book was released on 1987 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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

Download or read book Synthesis and Studies of Mo and W Complexes for 2N Reduction written by Jia Min Chin and published by . This book was released on 2010 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Book Preparation and Reaction of the Thiolate Hybride Complexes of Molybdenum

Download or read book Preparation and Reaction of the Thiolate Hybride Complexes of Molybdenum written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis describes studies on the synthesis and reactivity of a variety ofmolybdenum thiolate hydride complexes; tungsten complexes were also prepared forcomparison. The original purpose of this research was to examine the behaviour of sulphurligatedmolybdenum complexes as models for the molybdenum site in nitrogenase, but thiswork has demonstrated that the 5-coordinated complexes [MoH(SC6H2R3-2,4,6)3(PR1Ph2)] (R= Me or Pr'; R1 = Me or Et) are very reactive versatile starting materials for thepreparation of a wide range of derivatives, some of which model aspects of the chemistry ofother molybdenum enzymes such as xanthine oxidase.It is known that the reaction of thiols HSC6H2R3-2,4,6 with [MoH4(PR'Ph2)4] or trans-[Mo(N2)2(PMePh2)4] produces unsaturated thiolato-hydride complexes of molybdenum(IV)[MoH(tipt)3(PMePh2)] (A) (tipt = SC6H2PrV-2,4,6). Here we report an extension of thesestudies in which we have prepared the oxygen-sensitive, five- and six-coordinated complexes[MoH(SC6H4F)3(PMePh2)] (2.3) and [MoH(SC6HF4-2,3,5,6)3(PMePh2)2] (2.1) and[MoH(SC6F5)3(PMePh2)2] (2.4).Some reactions of (2.3), (2.1) and (2.4) have been investigated, including the reactionof (2.4) with carbon monoxide which yields [Mo(SC6F5)2(CO)2(PMePh2)2] (6.7). Thereaction of (2.1) with pyridine gives [MoH(SC6HF4-2,3,5,6)3(C5H5N)(PMePh2)] (6.1).The reaction of the electron-deficient hydride thiolate complex [MoH(tipt)3(PMe2Ph)2](B) with phenylacetylene gives the novel square pyramidal, diamagnetic phosphoniumalkylidenecomplex[MoO{=C(Ph)CH=C(Ph)CH2PMe2Ph)(SC6H2Pri3-2,4,6)3](3E), whereasthe reaction of /Molylacetylene with (A) yields the novel phosphonium ylide complex[MoO(SC6H2Pri3)2(HC=CC6H4Me-4){(C6H4Me-4) (C=CHPMePh2)}](3D),thathas relevanceto the species derived from xanthine oxidase when it is inhibited by aldehydes. These twocomplexes have been characterised by X-ray structure determination. [WH(tipt)3(PMe2Ph)2j(C) with phenylacetylene and p-tolylacetylene gives products resulting from oligomerisationreactions.In the reaction o f [MoH(tipt)3(PMePh2)] (A) with hydrazines, both binding of hydrazineto Mo and disproportionation/reduction have been observed. The bright green andtemperature- and oxygen-sensitive complex [MoH(tipt)3(NH3)(PMePh2)J (4.1) has beenobtained from the reaction of NH2NH2 with (A). Its X-ray structure determination at -10°Cshows that it is a hydride ammonia complex with trigonal bipyramidal geometry. Thereaction of phenylhydrazine with (A) gives dark green single crystals that have been thesubject of an X-ray crystallographic analysis. This compound crystallised in a much-distortedtrigonal bipyramidal geometry and is formulated as [MoH(tipt)3(NH2NHPh)(PMePh2)] (4.4).Isocyanides are substrates or inhibitors of nitrogenase. The interaction of isocyanides withthe five- and six-coordinate hydride complexes has been investigated. The reaction of[MoH(tipt)3(PMePh2)] (A) with MeNC and t-BuNC and also the reaction of[WH(tipt)3(PMe2Ph)2] (C) with MeNC, produce [MoH(tipt)2(MeNC)4] (5.1), [MoH(tipt)2('-BuNC)4] (5.3) and [WH(tipt)2(MeNC)4] (5.2) respectively. The structures of these complexeshave been confirmed by X-ray structure determination.The reaction of molybdenum hydride complexes with carboxylic acids give productswhich show carboxylate groups in their IR and NMR spectra.

Book Synthesis and Characterization of Several Molybdenum Chloride Cluster Compounds

Download or read book Synthesis and Characterization of Several Molybdenum Chloride Cluster Compounds written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigation into the direct synthesis of Mo4Cl(P(C2H5)3)4 from Mo2(OAc)4 led to a synthetic procedure that produces yields greater than 80%. The single-crystal structure disclosed a planar rectangular cluster of molybdenum atoms. Metal-metal bond distances suggest that the long edges of the rectangular cluster should be considered to be single bonds and the short metal-metal bonds to be triple bonds. This view is reinforced by an extended Hueckel calculation. Attempts to add a metal atom to Mo4Cl(PR3)4 to form Mo5Cl10(PR3)3 led instead to a compound with the composition Mo8Cl16(PR3)4. Solution and reflectance uv-visible spectra and x-ray photoelectron spectra suggest that tetranuclear molybdenum units are present. The facile reaction between Mo8Cl16(PR3)4 and PR3 imply that the linkage between tetrameric units is weak.