Ternary vanadium system

A variety of such ternary catalytic systems has been developed for diastereoselective carbon-carbon bond formations (Table). A Cp-substituted vanadium catalyst is superior to the unsubstituted one,3 whereas a reduced species generated from VOCl3 and a co-reductant is an excellent catalyst for the reductive coupling of aromatic aldehydes.4 A trinuclear complex derived from Cp2TiCl2 and MgBr2 is similarly effective for /-selective pinacol coupling.5 The observed /-selectivity may be explained by minimization of steric effects through anti-orientation of the bulky substituents in the intermediate. 

Ray] Raynor, G.V., Rivlin, V.G., Phase Equilibria in Iron Ternary Alloys. 10. Critical Evaluation of Constitution of Cobalt-Iron-Vanadium System , Int. Met. Rev., 28(4), 211-227 (1983) (Phase Diagram, Phase Relations, Review, 29)... 

Rag] Raghavan, V, The C-Fe-V (Carbon-Iron-Vanadium) System in Phase Diagrams of Ternary Iron Alloys , ASM International, Materials Park, OH, 111-125 (1987) (Phase Diagram, Review, 41)... 

Metal-induced reductive dimerization of carbonyl compounds is a useful synthetic method for the formation of vicinally functionalized carbon-carbon bonds. For stoichiometric reductive dimerizations, low-valent metals such as aluminum amalgam, titanium, vanadium, zinc, and samarium have been employed. Alternatively, ternary systems consisting of catalytic amounts of a metal salt or metal complex, a chlorosilane, and a stoichiometric co-reductant provide a catalytic method for the formation of pinacols based on reversible redox couples.2 The homocoupling of aldehydes is effected by vanadium or titanium catalysts in the presence of Me3SiCl and Zn or A1 to give the 1,2-diol derivatives high selectivity for the /-isomer is observed in the case of secondary aliphatic or aromatic aldehydes. 

Other common anode materials for thermal batteries are lithium alloys, such as Li/Al and Li/B, lithium metal in a porous nickel or iron matrix, magnesium and calcium. Alternative cathode constituents include CaCr04 and the oxides of copper, iron or vanadium. Other electrolytes used are binary KBr-LiBr mixtures, ternary LiF-LiCl-LiBr mixtures and, more generally, all lithium halide systems, which are used particularly to prevent electrolyte composition changes and freezing out at high rates when lithium-based anodes are employed. 

Catalyst fusion is essential to bring and keep the py-rosulfatc-vanadium oxide system into a homogeneous state which is the basis for operating the system at the eutectic in the ternary phase diagram. The reaction mechanism and the fact that the operation point of the... 

These observations on the sulfuric acid catalyst arc full in line with the general thermodynamic behaviour of fused catalyst systems. The mctastablc solid in Figure 2 has to be replaced in this case by a cascade of the partly reduced vanadium ternary sulfates. The processes sketched above occur under thermodynamic control in a quaternary phase diagram, vanadium-oxygen-sulfur-alkali, as illustrated by the reversibility of the exsolution of the partly reduced vanadium compounds under suitable partial pressures of oxygen... 

The most studied systems for oxidative propane upgrading are vanadium [2], vanadium-antimony [3], vanadium-molybdenum [4], and vanadium-phosphorus [5] based catalysts. Another family of light paraffin oxidation catalysts are molybdenum based systems, e.g. nickel-molybdates [6], cobalt-molybdates [7] and various metal-molybdates [8-9]. Recently, we investigated binary molybdates of the formula AM0O4 where A = Ni, Co, Mg, Mn, and/or Zn and some ternary Ni-Co-molybdates promoted with P, Bi, Fe, Cr, V, Ce, K or Cs [10-11]. A good representative of these systems is the composition Nio.5Coo.5Mo04 which was recently selected for an in depth kinetic study [12] and whose mechanistic aspects are now further illuminated here. 

Koel] Koester, W., Schmid, H., Iron-Cobalt-Vanadium Ternary System. Part I (in German), Arch. 

Koe2] Koester, W., Schmid, H., Iron-Cobalt-Vanadium Ternary System. Part II (in German), Arch. Eisenhuettenwes., 26(7), 421-425 (1955) (Phase Diagram, ExperimentaL Phase Relations,, , 7)... 

Dar] Darby, J.B., Beck, P.A., Sigma Phase in Certain Ternary Systems with Vanadium , Trans. 

Vog] Vogel, V.R., Martin, E., About the Iron-Carbon-Vanadium Ternary System (in German), Arch. Eisenhuettenwes., 4(10), 487-495 (1931) (Morphology, Phase Diagram, Experimental,, 11)... 

Wev] Wever, F., Rose, A., Eggers, H., Contribution to the Iron Comer of the Iron-Vanadium-Carbon Ternary System (in German), Mitt. Kaiser Wilhelm Institute Eisenforsch., 18, 239-246 (1936) (Phase Diagram, Phase Relations, Experimental,, 7)... 

A brief introduetion to the spectroscopic properties of vanadium(IV) is provided, along with identification of key concepts crucial to the successful application of EPR methods to research questions in the field. Specific discussions of EPR spectroscopies, sueh as continuous wave and pulsed methods, have been recently reviewed [19,20]. The discussion of the use of VO " ions as spin probes by N.D. Chasteen remains a seminal review paper in the field for its complete overview of the speetroseopie properties of the ion and application to biological systems [21]. Numerous reviews on the biochemmical activity of vanadium compounds are available [22-26], and the rationales for development and synthetic routes to new vanadium compounds are also reported [27,28] A reeent study evaluated the in-vitro activity of 22 compounds currently studied in the literature [29]. In this review, EPR s role in the delineation of structure, chemistry, and in-vivo behavior of vanadium compounds will be discussed. The first seetion of die review foeuses on the use of EPR for the description of solution structures, ternary eomplex formation, and redox chemistry of vanadium(IV) and (V) compounds, wifli the general flieme of highlighting in-vitro studies. This seetion is followed by a diseussion of die application of EPR for in-vivo investigations of vanadium cellular uptake, pharmacokinetics, and in-vivo coordination structure. 

We were unable to determine the relationship between vanadium concentration in the electrolyte and temperature on the one hand, and limiting current density on the other (Table 4.5.3). Most likely, this is due to the fact that the electrolyte contains a certain amount of vanadium(III) species. The presence of V(ni) ions can significantly decrease the liquidus temperature of the studied system [18] (in the presence of VCI3 the system changes from ternary to quaternary). 

Spectrophotometric determination of the binary complex Spec determination of the violet complex in acidic medium Extraction-spectrophotometric determination of the system V(V)-3,5-dinitrocatechol (DNC)-brilliant green chelate complex Extraction with H-butanol and spec X = 390 nm of a ternary complex (vanadium oxine H-butanol = 1 2 2)... 

Kaliva M, Kyriakakis E, Gabriel C, Raptopoulou CP, Tarzis A, Tuchangues JP, Salifoglou A (2006) Synthesis isolation, spectroscopic and structural characterization of a new pH complex structural variant from the aqueous vanadium(V)-peroxy-citrate ternary system. Inorg Chim Acta 359 4535 548... 

---