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  • reaction
  • The water oxidation reaction might take place at that potential (the standard potential of 1.23 V versus a standard hydrogen electrode) but such a reaction should not lead to a buildup of detectable Pt( IV ) species. (rsc.org)
  • Moreover, quantitative peak-fitting analysis showed that the fraction of non-metallic Pt species matched the ratio of the surface to total Pt atoms in the nanoparticles, which suggests that Pt oxidation only takes place at the surface of the Pt nanoparticles on the PEFC cathode, and the inner Pt atoms do not participate in the reaction. (rsc.org)
  • It appears that Cr(V) is not generated directly from the Cr(VI)-formate reaction but arises instead from oxidation of Cr(IV) by Cr(VI). (brillonline.com)
  • When the Cr(VI)-formate reaction is allowed to go to completion in the presence of [Cl(NH 3 ) 5 Co] 2+ , a scavenger for Cr(II), 84-86% of the Cr(VI) taken is found to be converted to Cr(II), indicating that nearly all of the reacting system proceeds through Cr(IV) and bypasses the more usual state Cr(III). (brillonline.com)
  • metals
  • Olefin Metatheses and Related Reactions Initiated by Carbene Derivatives of Metals in Low Oxidation States. (docme.ru)
  • Minireviews T. J. Katz Olefin Metathesis Olefin Metatheses and Related Reactions Initiated by Carbene Derivatives of Metals in Low Oxidation States Thomas J. Katz* Keywords: alkenes · alkynes · enynes · initiators · metathesis Experiments carried out 24 years ago with tantalum carbenes have led to the much cited hypothesis that metals (other than ruthenium) must be in their highest oxidation states for their carbene derivatives to initiate olefin metatheses. (docme.ru)
  • 6a, Despite these results, a number of recent publications assert or suggest that carbene derivatives of early transition metals initiate olefin metatheses only if the metals are in their highest oxidation states. (docme.ru)
  • 10, Because these are the oxidation states of the metals in the most effective tungsten and molybdenum carbene initiators used today (but not in the even more effective ruthenium carbenes), it has been proposed that for Fischer tungsten carbenes to initiate olefin metatheses they must first be oxidized to ill-defined species in DOI: 10.1002/anie.200462442 Angew. (docme.ru)
  • atoms
  • Conceptually, the oxidation state, which may be positive, negative or zero, is the hypothetical charge that an atom would have if all bonds to atoms of different elements were 100% ionic , with no covalent component. (wikipedia.org)
  • Additionally, oxidation states of atoms in a given compound may vary depending on the choice of electronegativity scale used in their calculation. (wikipedia.org)
  • State also known as Oxidation Number Oxidation state (number) is the charge an atom would have if existed as an ion Rule #1 Atoms of an element are assigned an oxidation number of 0. (prezi.com)
  • Rule #5 Sum of oxidation numbers of all atoms of an electrically neutral compound is 0. (prezi.com)
  • Sum of oxidation number of all atoms is equal to the overall charge of the ion. (prezi.com)
  • Additionally, a change in the valence band structure due to the oxidation of platinum atoms was also observed at large positive voltages. (rsc.org)
  • These include the Bi4 cluster compound Bi4(NONAr)2, in which the bismuth atoms exist in an unprecedented mixed valent arrangement and may be assigned oxidation states of 0, +1 or +2, and the tribismuthane cluster [Bi3(NONtBu), which features the first structurally characterised Bi3 chain. (vuw.ac.nz)
  • methane
  • Pronounced Ligand Effects and the Role of Formal Oxidation States in the Nickel-Mediated Thermal Activation of Methane. (docme.ru)
  • Angewandte Chemie DOI: 10.1002/anie.200603266 Cationic Gas-Phase Species Pronounced Ligand Effects and the Role of Formal Oxidation States in the Nickel-Mediated Thermal Activation of Methane** Maria Schlangen, Detlef Schrder,* and Helmut Schwarz* Dedicated to Professor Gerhard Erker on the occasion of his 60th birthday. (docme.ru)
  • density
  • In the valence band spectra, the density of electronic states near the Fermi edge reduces with decreasing particle size, indicating an increase in the electrocatalytic activity. (rsc.org)
  • valence
  • The work presented in this thesis describes the synthesis and stabilisation of heavy p-block elements (defined herein as being those with 5s/p and 6s/p valence electrons) in low oxidation states using sterically demanding ligands based on a di(amido)siloxane framework ([(O{SiMe2N(R)}-, abbrev. (vuw.ac.nz)
  • initiate
  • The hypothesis legitimizes the uniqueness of high-oxidation-state molybdenum and tungsten carbenes as effective initiators, and it means that the Fischer tungsten carbenes that even earlier were found to initiate olefin metatheses and related transformations must be oxidized before they can be effective. (docme.ru)
  • high
  • A corollary then is that high-oxidation-state tantalum [14c, and tungsten oxo derivatives[14c, were the first metal carbenes that directly initiated productive olefin metathesis. (docme.ru)
  • element
  • In inorganic nomenclature, the oxidation state is represented by a Roman numeral placed after the element name inside a parenthesis or as a superscript after the element symbol. (wikipedia.org)
  • This approach yields correct oxidation states in oxides and hydroxides of any single element, and in acids such as H 2 SO 4 or H 2 Cr 2 O 7 . (wikipedia.org)