14040-11-0Relevant academic research and scientific papers
Investigation of the catalytic properties of the thermally activated dichloro-tetracarbonyl-tungsten in olefin metathesis reaction
Bencze, Lajos,Szalai, Gabor,Overton, Tina L.
, p. 5 - 7 (1997)
Combined catalytic, preparative and spectroscopic studies revealed that the ring-opening metathesis polymerisation of norbornene initiated by thermally activated W (CO)4Cl2 (I) proceeds mainly on the surface of a solid decomposition product formed in situ.
REACTIONS OF BIMETALLIC GROUP VI COMPLEXES II. PHOSPHINE AND PHOSPHITE DERIVATIVES; LIGAND TRANSFER AND OXIDATIVE DECARBONYLATION; THE CRYSTAL STRUCTURE OF
Quere, J. L. Le,Petillon, F. Y.,Guerchais, J. E.
, p. 127 - 136 (1983)
Triphenylphosphine and trimethylphosphite react with (M, M'=Mo, W) (II) to give which on heating revert to II.On prolonged heating is formed. reacts with I2 to give fo
Crystal structure of trans- [W(CO)4(n2-C2H4)2] and IR 1H NMR studies of the reactions of this and related ethene carbonyl complexes of tungsten(0), [W(CO)(n)(n2-C2H4)6-(n)] (n = 3-5)
Szymanska-Buzar, Teresa,Kern, Krystyna,Downs, Anthony J.,Greene, Timothy M.,Morris, Leigh J.,Parsons, Simon
, p. 407 - 416 (1999)
The structure of trans-[W(CO)4 (η2-C2H4)2] 1 has been determined by X-ray crystallography at 293 K [orthorhombic, space group Aba2, a = 12.458(3), b = 6.370(2), c = 12.557(3)A, Z = 4, R = 0.022] to confirm that the C=C bonds of the two ethene ligands are mutually staggered while eclipsing the central W(CO)4 unit. Reversible isomerisation of trans- to cis-[W(CO)4(η2-C2H4)2] 2 under the action of selective irradiation has been shown to occur in solid argon matrices at 14-16 K. 1H NMR measurements have also been applied to the identification of not only 1 and 2 but also the labile 1Be complexes [W(CO)5(η2-C2H4)] 3, mer-[W(CO)3(η2C2H4)3] 4, and fac-[W(CO)3(η2-C2H4)3] 5 formed by broad-band UV-visible photolysis of ethene-saturated hydrocarbon solutions of 1 or [W(CO)6] in the temperature range 200-293 K. In these circumstances the mixed ethene carbonyl complexes 2-5 decay thermally with dissociation of an ethene ligand and substitution by CO in reactions which have been monitored by reference to the relevant 1H NMR signals. Pseudo-first-order decay constants in the range 0.6-12 x 10-4 s-1 have thus been estimated with temperature-dependences implying activation energies, E(a), that decrease in the order 3 > 2 > 4 > 5.
Reactivity of cyano- And isothiocyanatoborylenes: metal coordination, one-electron oxidation and boron-centred Br?nsted basicity
Arrowsmith, Merle,Braunschweig, Holger,Elezi, Dren,Fantuzzi, Felipe,H?rterich, Marcel,Hagspiel, Stephan,Krummenacher, Ivo,Rempel, Anna,Vargas, Alfredo
, p. 7937 - 7942 (2021)
Doubly base-stabilised cyano- and isothiocyanatoborylenes of the form LL′BY (L = CAAC = cyclic alkyl(amino)carbene; L′ = NHC = N-heterocyclic carbene; Y = CN, NCS) coordinate to group 6 carbonyl complexesviathe terminal donor of the pseudohalide substituent and undergo facile and fully reversible one-electron oxidation to the corresponding boryl radical cations [LL′BY]˙+. Furthermore, calculations show that the borylenes have very similar proton affinities, both to each other and to NHC superbases. However, while the protonation of LL′B(CN) with PhSH yielding [LL′BH(CN)+][PhS?] is fully reversible, that of LL′B(NCS) is rendered irreversible by a subsequent B-to-CCAAChydrogen shift and nucleophilic attack of PhS?at boron.
As a source of semi-interstitial phosphorus ligands in cobalt carbonyl clusters
Dreher, Cornelia,Zabel, Manfred,Bodensteiner, Michael,Scheer, Manfred
, p. 5187 - 5191 (2010)
The PH3-containing complex [(CO)4W(PH 3)2] (1) is synthesized in good yields by the one-pot reaction of [(CO)4W(nbd)] (nbd = norbonadiene) with P(SiMe3)3 and subsequent methanolysis of the reaction mixture. The further reaction of [(CO)4W(PH3) 2] with [Co2(CO)8] results in three novel cobalt clusters, [Co8(CO)18(μ6-P) 2(μ-CO)] (2), [Co10(CO)18(μ7- P)2(μ-CO)6] (3), and [[Co3(CO) 8{μ4-PW(CO)5}][(μ4-P)Co 3(CO)9]] (4). All products have been comprehensively characterized including X-ray diffraction.
Carbonyltungsten(0) complexes of acryloylferrocene: Synthesis and characterization
Bo?a, Dilek Ay?e,?zkar, Saim
, p. 3293 - 3297 (2006)
Photolysis of hexacarbonyltungsten(0) in the presence of acryloylferrocene in n-hexane solution at 10 °C yields pentacarbonyl(η2-acryloylferrocene)tungsten(0) (1) as the only photo-substitution product, different from the general reaction patte
Synthesis and characterisation of novel complexes containing group 15 elements and their potential use as molecular precursors for the formation of transition metal pnictides
Scheer, Manfred,Vogel, Ulf,Becker, Uta,Balazs, Gabor,Scheer, Petra,Hoenle, Wolfgang,Becker, Michael,Jansen, Martin
, p. 135 - 141 (2005)
The reaction of [{W(CO)5}2PCl] with K[Co(CO) 4] yields the novel compounds [{W(CO)4Co 2(CO)6}{μ3-PW(CO)5}2] (3) and [{(CO)4WCo3(CO)su
Silicon-containing carbene complexes. 6. Stable 16-electron carbonyl carbene complexes of tungsten(0), molybdenum(0), and chromium(0)
Schubert, Ulrich,Hepp, Wolfgang,Müller, Johannes
, p. 173 - 175 (1986)
On warming (CO)5W=C(NR2)SiPh3 (NR2 = NMe2, 1a, NC5H10, 1b) under vacuum, a CO ligand is eliminated and 16-electron carbene complexes (CO)4W= C(NR2)SiPh3 (2a,b) are formed as stable compounds. Analogous chromium and molybdenum complexes (CO)4M=C(NC5H10)SiPh3 (M = Mo, 2c, Cr, 2d) are already formed during the preparation of (CO)5M=C-(NC5H10)SiPh3 (1c,d). The reaction is readily reversed on bubbling CO through solutions of 2. X-ray structure determination of (CO)4W=C(NC5H10)SiPh3 (2b) shows that the vacant coordination site at the metal is capped by a phenyl group of the SiPh3 substituent. However, the long W-C(phenyl) distances exclude strong bonding interaction. The driving force for the conversion of 1 to give 2 seems to be relaxation of the steric strain within the carbene ligand.
Photochemische Reaktion von Pentacarbonyl(1-ethoxy-2-methyl-2-propenyliden)wolfram und Dekacarbonyldirhenium
Kreiter, Cornelius G.,Schufft, Sabine,Heckmann, Gert
, p. 163 - 172 (1992)
Upon UV irradiation at 223 K pentacarbonyl (1-ethoxy-2-methyl-2-propenylidene)tungsten (1) and decacarbonyl-dirhenium (2) yield enneacarbonyl(μ-η1:3-1-ethoxy-2-methyl-2-propenylidene)ditungsten (3), octacarbonyl(μ-η1:3-1-ethoxy-2-methyl-2-propenylidene)dirhenium (4) and tridecacarbonyl-μ-η1:3-1-ethoxy-2-methyl-2-propenylidene)dirhenium-tungsten (5).The molecular structure of the hetero-trinuclear compound 5 was determined by X-ray structure analysis.The three metal centers form a bent Re-W-Re spine.One of the Re-W bonds is bridged by a carbonyl and the η1:3-1-ethoxy-2-methyl-2-propenylidene ligand.
Organic synthesis via transition metal complexes. 112. Reactivity enhancement of group VI Fischer carbene complexes by copper and rhodium catalysts: Experimental proof of a carbene rhodium complex as an intermediate
G?ttker-Schnetmann, Inigo,Aumann, Rudolf,Bergander, Klaus
, p. 3574 - 3581 (2001)
Rhodium(I) compounds were found to efficiently catalyze reactions of Fischer carbene complexes. It was shown that the thermally quite unreactive tungstaoctatetraenes 14a-d were readily transformed into spiro-fused vinylcyclopentadienes 15a-d in the presence of catalytic amounts of RhCl3·3H2O in MeOH or [(COD)RhCl]2. A reactivity enhancement was observed also for the transformation of the tungsten complex 8a into vinylcyclopentadiene 10a. Experimental proof for the intermediacy of carbene rhodium complexes in these reactions was provided by preparation of the rhodaoctatetraene 16c from the reaction of the tungsten compound 14c with a stoichiometric amount of [(COD)RhCl]2. The carbene rhodium compound 16c was transformed into the vinylcyclopentadiene 15c thermally in a smooth reaction and showed a catalytic activity similar to [(COD)RhCl]2. Not only rhodium but also copper compounds were found to be good catalysts for the π-cyclization of tungstaoctatetraenes.
