12131-22-5Relevant academic research and scientific papers
Conformational isomers and isomerization of group 6 (Cr, Mo, and W) metal-bis(toluene) sandwich complexes probed by variable-temperature electron spectroscopy
Lee, Jung Sup,Kumari, Sudesh,Yang, Dong-Sheng
, p. 11277 - 11284 (2010)
Group 6 metal (Cr, Mo, and W)-bis(toluene) sandwich complexes are synthesized in a laser-vaporization molecular beam source. Conformational isomers and isomerization of these complexes are studied by variable-temperature pulsed-field-ionization zero-elect
Homoleptic Molybdenum Complexes of α,β-Unsaturated Amides and Esters: Preparation and Crystal Structures
Schmidt, Thomas,Goddard, Richard
, p. 1563 - 1568 (1995)
Bis(η6-toluene)molybdenum reacted with N,N-dimethylacrylamide and methyl methacrylate under mild conditions with exchange of both arene ligands to yield the new homoleptic tris(1-oxa-1,3-diene)molybdenum complexes 3> and 3> in 84 and 50percent yield, respectively.The yellow, crystalline compounds exhibit three-fold symmetry in solution (1H and 13C NMR spectra) and also in the solid state (crystal structure analyses).The ligand bonding is best described as intermediate between η4 and κ2,η2 co-ordination.For the first time in the tris(oxadiene) complex series, a non-symmetrical isomer can be isolated in low yield from the crude product mixture of the ester complexation reaction and has been characterised spectroscopically.
Comparative regiochemistry of protonation of (η6-C6H 5R)(1,1′,1″-tris(2-diphenylphosphinomethyl)ethane)Mo(0) (R=H, Me and SiMe3)
Asirvatham, Victor S.,Khan, Masood A.,Ashby, Michael T.
, p. 275 - 279 (2007/10/03)
Our previous mechanistic studies of 1 (R=H) demonstrate it is protonated to give a metal-hydride via a mechanism that involves indirect exo attack on the arene ligand followed by endo proton transfer to the metal. The toluene derivative 1 (R=Me) reacts via a similar mechanism with unusual ortho/meta/para=61:36:3% selectivity. In contrast, the first equivalent of proton hydrolyzes the TMS group of 1 (R=SiMe3) under surprisingly mild conditions and the second equivalent reacts with the product 1 (R=H) to give the metal-hydride via the aforementioned indirect mechanism.
Synthesis of 6-NC5H3Me2-2,6)(η6-C6H5Me)>: Photoelectron Spectra and Electronic Structure of some Transition-metal η6-2,6-Dimethylpyridine Complexes
Ashmore, Jennifer,Green, Jennifer C.,Green, Malcolm L. H.,Smith, Marcus Lovell,Mehnert, Christian,Wucherer, Edward J.
, p. 1873 - 1878 (2007/10/02)
Synthesis of the mixed-ring sandwich compound 6-NC5H3Me2-2,6)(η6-C6H5Me)> is reported.Photoelectron spectroscopic studies of 6-NC5H3Me2-2,6)2>, where M = Ti, V, Cr or Mo and 6-NC5H3Me2-2,6)(η6-C6H5Me)> established that these sandwich compounds are electronically very similar to the bis(arene) analogues, and that 2,6-dimethylpyridine is a better δ acceptor than benzene.
η6-ARENE METAL COMPLEXES. SYNTHESIS, REACTIVITY AND CRYSTAL AND MOLECULAR STRUCTURE OF 6-1,3,5-Me3C6H3)2>AlCl4 AND THE ONE-POT SYNTHESIS OF V(η6-1,3,5-Me3C6H3)2, Cr(η6-MeC6H5)2 AND Mo(η6-MeC6H5)2
Calderazzo, Fausto,Invernizzi, Renzo,Marchetti, Fabio,Masi, Francesco,Moalli, Angelo,et al.
, p. 53 - 60 (2007/10/02)
The products of the reduction of VX3 by the Al/AlX3 (X=Cl, Br, I) system in 1,3,5-Me3C6H3 (mes), AlX4, have been isolated and structurally characterized for X=Cl.Crystal data: C18H24AlCl4V; M=460.1; orthorhombic, space group Pnnm, a=15.078(5); b=14.391(3); c=10.481(3) Angstroem; U=2274(1) Angstroem3; Z=4; Dc=1.344 Mg m-3; ??(Mo-Kα1)=0.70930 Angstroem; μ=0.93 mm-1; F(000)=944; T=294 K.The structure consists of the discrete VMes2+ and AlCl4- ions, the former containing sandwiched, eclipsed arene ligands.In the parent hydrocarbon as medium, no further reduction of the vanadium(I) complex occurred even over long reaction times: in the presence of tetrahydrofuran, the crude primary product of the reaction was further reduced by the excess of aluminium affording bismesitylenevanadium(0), Vmes2, in good yields.The slight solubility of AlCl4 in mesitylene has been found to increase enormously by addition of the equivalent of AlCl3: this adduct clathrates additional mesitylene up to a critical ratio of the mesitylene/vanadium molar value, further addition of mesitylene giving a biphasic system.The new synthetic method used for Vmes2 has been extended to the preparation of the chromium(0) and molybdenum(0) complexes, Cr(η6-MeC6H5)2 and Mo(η6-MeC6H5)2, respectively.
Liquid-phase metal vapor chemistry: Rotary reactors and electron-beam evaporation sources
Ozin,Andrews,Francis,Hüber,Molnar
, p. 1068 - 1073 (2008/10/08)
A new rotatable metal atom reactor that allows electron-beam vaporizations of refractory materials into liquid solutions at reduced temperatures is described. This innovation demonstrably broadens the scope of synthesis from metal atoms and molecular high-temperature species. Details of the instrument and its operation are provided, together with results of studies of charged particle emissions, a description of techniques for quantifying the rate of metal atom deposition, and a description of a variable-temperature transfer tube for removing thermally labile compounds. A simple addition of the furnace that substantially reduces the power required to evaporate even the most refractory elements leads to dramatically increased vaporization rates for modestly powered 2-kW guns. The paper concludes with some test applications of the device in the liquid-phase electron-beam synthesis of some bis(η6-arene) complexes of titanium, vanadium, and molybdenum.
Electronic absorption spectra of molybdenum(0) bisarene complexes, (η6-Arene)2Mo(0)
Ketkov, S. Yu.,Domrachev, G. A.
, p. 187 - 195 (2007/10/02)
The UV and visible absorption spectra of (ν6-Arene)2Mo0 (Arene = benzene (I), toluene (II), m-xylene (III), mesitylene (IV)) in the vapor phase and in the pentane solution have been investigated.Rydberg series converging to the ioniz
SYNTHESIS AND POLYMERISATION OF BIS(η-STYRENE)MOLYBDENUM AND RELATED STUDIES: CRYSTAL STRUCTURES OF Mo(η-C6H5CH2CH=CH2)2 AND BF4
Green, M. L. H.,Treurnicht, I.,Bandy, J. A.,Gourdon, A.,Prout, K.
, p. 145 - 166 (2007/10/02)
The synthesis of the compounds Mo(η-C6H5R)2, where R = CH=CH2, 4-C6H4CH=CH2 and CH2CH=CH2 is described.The crystal structure of Mo(η-C6H5CH2CH=CH2)2 has been determined.These vinyl monomers are polymerised by free radical initiation using AIBN.Di-η-benzenemolybdenum is lithiated by BunLi/Me2NCH2CH2NMe2 to give a bis(η-lihiobenzene)molybdenum derivative, which reacts with D2O, MeI, or SiMe3Cl to give Mo(η-C6H5R)2, where R = D, Me or SiMe3 respectively.The dilithio system reacts with SiMe2Cl2 to give a polymeric mixture containing ClnSiMe2Cl, and hydrolysis of this yields the disiloxane Mo(η-C6H5SiMe2OSiMe2-η-C6H5), whose crystal structure has been determined.Co-condensation of molybdenum atoms with dimethylphenylsilane gives Mo(η-C6H5SiMe2H)2, which is oxidised by aqueous HBF4 to give the compound BF4, whose crystal structure has been determined.
Cocondensation of chromium, molybdenum, and tungsten vapors with arenes and phosphorus ligands
Ittel, Steven D.,Van-Catledge, Frederic A.,Tolman, Chadwick A.
, p. 62 - 65 (2008/10/08)
Cocondensation of chromium vapors with P(OR)3 yields Cr(P(OR)3)6 in good yield when R = Me. When R = Et, the complex is formed at low temperatures and can be observed at room temperature, but steric interactions between ligands cause the complex to decompose upon attempted isolation. Both complexes can be reacted with H2 to form the respective CrH2(P(OR)3)5 complexes. Simultaneous cocondensation of Cr with P(OR)3 and an arene results in good isolated yields of Cr(η6-arene)(P(OR)3)3 complexes. Cocondensation of resistively heated Cr or electron beam heated Mo and W with arenes gives the expected M(η6-arene)2 complexes. Cocondensation of Mo in P(OMe)3 gives a low yield of Mo(P(OMe)3)6, and with W in P(OMe)3, a slurry of W metal in P(OMe)3 is the only product obtained directly. The high radiant energy from the evaporation source coupled with the photolytic instability of Mo(P(OMe)3)6 and the W analogue leads to decomposition of the desired products. W(P(OMe)3)6 can be formed by heating the slurry of W in P(OMe)3.
Reductive Preparation of Bis(arene)metal Complexes from Metal Halides in Solution using Potassium Atoms
Hawker, Pelham N.,Timms, Peter L.
, p. 1123 - 1126 (2007/10/02)
Some known bis(arene) complexes of zerovalent Ti, V, Cr and Mo have been synthesised in a new way by stepwise reduction of solutions of the metal chlorides in tetrahydrofuran and arene, using K atoms condensed into the solutions at -110 deg C under vacuum in a rotary reactor.The extent of reduction was followed by observing colour changes in the solutions.With Ti and V, the initial products were anionic forms of the bis(arene) complexes, which were oxidised to give the zerovalent compounds.The method is a useful way of making 0.1-1 g samples of some bis(arene)titanium complexes and bis(naphthalene) complexes of V, Cr, and Mo which are otherwise accessible only by using the transition-metal atoms as reagents.
