Theoretical studies of organometallic compounds. 5. Alkyne and vinylidene complexes of molybdenum and tungsten in high-oxidation states.

1993 ◽  
Vol 115 (25) ◽  
pp. 11930-11938 ◽  
Author(s):  
Ralf Stegmann ◽  
Arndt Neuhaus ◽  
Gernot Frenking
Keyword(s):  
Organometallic Compounds ◽  
Oxidation States ◽  
Theoretical Studies ◽  
Vinylidene Complexes ◽  
High Oxidation ◽  
And Tungsten

Complexes of niobium, tantalum and tungsten pentahalides with fluorinated ditertiary arsines

1976 ◽  
Vol 29 (2) ◽  
pp. 433 ◽  
Author(s):  
DL Kepert ◽  
KR Trigwell
Keyword(s):  
Metal Complexes ◽  
Oxidation States ◽  
Metal Atoms ◽  
High Oxidation ◽  
Tungsten Hexachloride ◽  
And Tungsten

The fluorinated ditertiary arsines 1,2-bis(dimethylarsino)-3,3,4,4-tetrafluorocyclobutene, 1,2-bis(di- methylarsino)-3,3,4,4,5,5-hexafluorocyclopentene, and 1,2-bis(dimethy1arsino)-4-fluorobenzene react with niobium and tantalum pentachlorides and pentabromides, and with tungsten hexachloride, to form MX5(diarsine). These are the first metal complexes containing fluoro ligands coordinated to metal atoms in such high oxidation states.

Porphyry Cu-Au±Mo mineralization hosted by potassic igneous rocks: implications from the giant Peschanka porphyry deposit, Baimka Trend (North East Siberia, Russia)

2021 ◽  
pp. SP513-2020-178
Author(s):  
Andrey F. Chitalin ◽  
Ivan A. Baksheev ◽  
Yurii N. Nikolaev ◽  
Georgy T. Djedjeya ◽  
Yuliya N. Khabibullina ◽  
...  
Keyword(s):  
Tectonic Setting ◽  
Igneous Rocks ◽  
Oxidation States ◽  
Island Arcs ◽  
Porphyry Cu ◽  
North East ◽  
Average Grade ◽  
High K ◽  
High Oxidation ◽  
Other World

AbstractPorphyry Cu-Au±Mo mineralization at Peschanka is hosted by monzodiorite and monzonite intrusions with high-K calc-alkaline to shoshonitic compositions and dated at about 144.1±1.5 Ma, using U/Pb zircon ages. The Cretaceous intrusions are emplaced in a melange of Cretaceous island arcs, a tectonic setting comparable to other world-class porphyry Cu-Au deposits, such as Oyu Tolgoi, Mongolia, and Pebble, Alaska.Abundant primary magnetite contents of the Peschanka intrusions, as well as numerous gypsum and anhydrite veins, reflect the high oxidation states of their parental magmas. This mineralogical interpretation is confirmed by high whole-rock Fe2O3/FeO ratios and high V/Sc ratios of the rocks of up to 1.27 and up to 21.9, respectively. The whole-rock Eu/Eu& ratios of the Peschanka intrusions are ≥1 which is also typical for potassic igneous rocks with high oxidation states. Abundant amphibole and biotite phenocrysts of the intrusions as well as their high whole-rock Sr/Y ratios of up to 225 document significantly high H2O contents of the high-K magmas.Peschanka contains a resource of >9.5 Mt of copper at an average grade of 0.43 wt% and 16.5 Moz of gold at a high average grade of 0.23 g/t and, thus, representing one of the largest undeveloped greenfield copper projects worldwide. The vicinity of Peschanka still offers significant brownfields exploration potential.The hypogene vein-related and disseminated Cu-Au±Mo sulfide mineralization at Peschanka is structurally-controlled by significant NE-trending strike-slips that acted as the conduits for the hydrothermal fluids. The central part of the orebody consists of high-grade N-S trending sheeted quartz-bornite veining with unusually high vein densities. The highest Cu and Au grades are directly correlated with high vein densities.Peschanka is defined by distinct hydrothermal alteration zones including potassic, phyllic, propylitic and argillic assemblages, but a distinct lack of advanced argillic alteration. The mineralization itself is also zoned ranging from a central Mo-Cpy-Bn sulfide assemblage to a peripheral Py-Mt-dominated zone (“pyrite-shell”). Late-stage polymetallic assemblages overprint and surround the main stockwork zone.

The Important Role of High Oxidation States in Cuprate Superconductors

1989 ◽  
pp. 165-168
Author(s):  
S. X. Dou ◽  
H. K. Liu ◽  
J. P. Zhou ◽  
A. J. Bourdillon ◽  
C. C. Sorrell
Keyword(s):  
Cuprate Superconductors ◽  
Oxidation States ◽  
High Oxidation

Alkin-Komplexe des Rheniums in hohen Oxidationsstufen / Alkyne Complexes of Rhenium in High Oxidation States

1990 ◽  
Vol 45 (6) ◽  
pp. 876-886 ◽  
Author(s):  
Wolfgang A. Herrmann ◽  
Josef K. Felixberger ◽  
Josef G. Kuchler ◽  
Eberhardt Herdtweck
Keyword(s):  
Diffraction Study ◽  
Scale Up ◽  
Oxidation States ◽  
X Ray Diffraction ◽  
X Ray ◽  
Reducing Conditions ◽  
Molar Amount ◽  
High Oxidation ◽  
Alkyne Complexes ◽  
Type 3

The class of π-alkyne complexes of metals in medium and high oxidation states has been extended by the type CH3ReO2(RC≡CR′) (3a—i). Exchange of alkyne for oxo ligands under reducing conditions has been employed as a new general synthesis. Compounds 3 are thus obtained by reaction of methyltrioxorhenium(VII) (1) with the alkynes 2a—i in the presence of a ca. 1.1-fold molar amount of polymer-bound triphenylphosphane as reducing agent (desoxygenation). The structural characterization was carried out for the example of the tolan complex 3 e by virtue of a single-crystal X-ray diffraction study at —80 °C, according to which the description of compounds 3 as “rhenacyclopropenes” seems justified. Evidence from NMR investigations of 3 a and 3 c shows that no fast rotation of the respective alkyne ligand around the axis to the metal atom occurs on the NMR time scale up to at least 105 °C. A minimal rotation barrier of approximately 20 kcal/mol is thus to be estimated. Reaction of type 3 compounds (R = R′ = CH3, b; R = R′ = C2H5, c) with polymer-bound triphenylphosphane under more drastic conditions (boiling toluene) for two days effects further reduction, with the dinuclear, diamagnetic rhenium(IV) complexes 4b and 4c, resp., being formed. Sterically demanding alkynes (e.g., R = R′ = Si(CH3)3, C6H5) seem to prevent this type of reaction. According to an X-ray diffraction study, 4b has an equilateral Re2O-triangular core geometry, with the ligands O, CH3, and butyne(2) arranged in such a way that C2-symmetry results. The alkyne complexes reported here are the first ones of tetra- and pentavalent rhenium.

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