I. Introduction. Background. Focus of the review. Review procedure and results. The NEA-TDB data base system. Presentation of the selected data. II. Standards and Conventions. Symbols, terminology and nomenclature. Units and conversion factors. Standard and reference conditions. Fundamental physical constants. III. Selected Uranium Data. IV. Selected Auxiliary Data. V. Discussion of Data Selection. Elemental uranium. Aqua ions. Oxide, hydride and hydroxide species. VI. Discussion of Auxiliary Data Selection. Reference list. Authors list. Formula list. Discussion of selected references. Ionic strength corrections. Assigned uncertainties. The estimation of entropies.

Chemical thermodynamics of uranium

Mechanisms for formation, chlorination, dechlorination and destruction of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs)

The anaerobic photocatalytic reaction of methanol on Pt/TiO2 catalyst was studied by in situ Fourier transform IR and time-resolved IR spectroscopy. For the Pt/TiO2 catalysts reduced at high temperature, the capacity of methanol adsorption decreases with the increase of the Pt loading, indicating that Pt particles or atoms occupy some of the active sites on TiO2 for methanol adsorption. Surface species CH2O(a), CH2OO(a), and HCOO(a) are derived from the photocatalytic reaction of methanol on Pt/TiO2. The increase of gas-phase methanol or water accelerates the photoreaction and improves the activity of H2 production. When the catalysts are exposed to methanol, the strong electronic absorption on nanosecond to second time scale is observed, indicating that a great amount of long-lived electrons are produced in TiO2-based photocatalysts after band gap excitation. The decay rate of the long-lived electrons correlates well with the activity of H2 production. These results show that the long-lived electrons con...

Mechanistic Studies of Photocatalytic Reaction of Methanol for Hydrogen Production on Pt/TiO2 by in situ Fourier Transform IR and Time-Resolved IR Spectroscopy

Studies of long-range electron transfer (LRET) in systems where the redox partners are held at a fixed and rigid distance and orientation have achieved a central role in modern chemistry.1-14 The paradigmatic system in nature is the photosynthetic reaction center.2 Three levels of experimental design have been developed to study ET in an environment amenable to synthetic and physical control: linked donor-acceptor model compounds,3,4 redox-modified proteins,5,11-13 and modified protein-protein complexes.6-8,14 In the first level, the ET process necessarily takes place through a covalent and/or Hbonded pathway amenable to changes in distance and composition. The second level, where a redox-active inorganic complex is covalently attached to a surface amino acid residue of a redox protein, introduces the full complexity of intraprotein ET between centers covalently linked to well-defined sites within a protein. This raises such issues as the relative importance of “pathways” that involve through-space vs through-bond coupling, with the latter subdividing into covalent bonds and hydrogen bonds.9 As a variant on this approach, mixed-metal hemoglobin hybrids exhibit intersubunit ET10 and thus necessarily introduce the issue of ET across a noncovalent protein-protein interface, but do so in a context where the intersubunit contacts and potential ET pathways are structurally well-defined. This review focuses on the study of ET between proteins that form noncovalent complexes, a higher order problem that introduces additional complexities not seen in the other systems and not fully appreciated when the current interest in LRET began.15,16 In the study of physiological protein-protein complexes such as that between yeast cytochrome c peroxidase (CcP) and cytochrome c (Cc),6,7,14,17 one begins without certain knowledge of the stoichiometry of binding, much less the site or sites on the protein surfaces where binding occurs, and without knowledge of the rules for protein-protein recognition and conformational interconversion that might control the ET process! The ET event occurs within a protein-protein complex across a dynamic proteinprotein interface, and as a consequence, the observed kinetics may depend not only on the ET process itself but also on the extent and stoichiometry of binding, as well as on the interfacial dynamics of docking. In short, as we18,19 and others20-22 have come to recognize, the first stage in the study of such interprotein ET does not involve the study of ET, but rather the use of ET measurements to study the stoichiometry and geometry of equilibrium binding as well as the dynamics of docking rearrangements. Only after successes in this stage of the enterprise does one † Northwestern University. ‡ University of Pittsburgh. § University of California. 2459 Chem. Rev. 1996, 96, 2459−2489

Theory and Practice of Electron Transfer within Proteinminus signProtein Complexes: Application to the Multidomain Binding of Cytochrome c by Cytochrome c Peroxidase.

https://pure.mpg.de/pubman/item/item_1332667_3/component/file_1449048/1332667.pdf

Performance, structure, and mechanism of CeO2 in HCl oxidation to Cl2

Thermochemistry of the Deacon Process

Equation reliant les enthalpies standard de formation pour MX n , MY n et MZ n d'un metal M avec la valence n

Thermochemistry of inorganic solids. 7. Empirical relations among enthalpies of formation of halides

A process for the efficient production of Cl2 from gaseous HCl, using a catalyst containing a transition metal oxide, an alkali metal chloride, and, optionally, a trivalent rare earth chloride, operates efficiently at moderate temperatures and without volatilization of the catalyst. The process comprises two steps: (1) a chloridizing step in which the HCl is contacted with the catalyst at an elevated temperatures, converting the transition metal oxide to a transition metal chloride with elimination of water; and (2) an oxidizing step in which the transition metal chloride produced in the first step is contacted with a source of oxygen at a temperature at least about 300° C. but less than 400° C. and sufficiently high that Cl2 is evolved and the transition metal chloride is reconverted to a transition metal oxide. The temperature of the oxidizing step is increased over that of the chloridizing step. Preferably, the transition metal oxide is MnO2, in which case the MnO2 is converted to MnCl2 in the first step with the release of Cl2. The transition metal oxide can also be Co2 O3, Co3 O4, Cr2 O3, NiO, Ni2 O3, Mo2 O3, or CuO.

Efficient method for the chemical production of chlorine and the separation of hydrogen chloride from complex mixtures

Thermochemistry of inorganic solids. 6. The enthalpies of formation of crystalline hydrates, ammoniates, and alcoholates, and some observations on heats of dilution

Examination of available standard enthalpies of formation of solid oxyhalide compounds (total of 35) of various metals from main groups to actinide series shows that the standard enthalpies of formation of these compounds can be correlated quantitatively with the enthalpies of formation of the corresponding oxides and halides of the same oxidation states by the equation ..delta..H/sub f//sup 0/(MO/sub x/X/sub y/) = a((2x/z)..delta..H/sub f//sup 0/(MO/sub z/2/) + (y/z)..delta..H/sub f//sup 0/(MX/sub z/)) + C, where z = 2x +y = the formal oxidation state of the metal, MO/sub x/X/sub y/ is the oxychloride, and MO/sub z/2/ and MX/sub z/ are the corresponding oxide and halide of the same oxidation state z. C is a correction factor in kcal/mol. For main and first transition-metal compounds, a = 1 and C = 0. For trivalent-state lanthanides, a = 2.155 +/- 0.12 and C = 257.8 +/- 1.3 or 250.4 +/- 1.2 kcal/mol. For tetravalent oxychlorides, a = 1 and C = 5 kcal/mo. For penta- and hexavalent compounds, a = 1 and C = 0. 6 references, 2 figures, 6 tables.

Mohamed W. M. Hisham

Papers

Thermochemistry of the Deacon Process

Thermochemistry of inorganic solids. 7. Empirical relations among enthalpies of formation of halides

Efficient method for the chemical production of chlorine and the separation of hydrogen chloride from complex mixtures

Thermochemistry of inorganic solids. 6. The enthalpies of formation of crystalline hydrates, ammoniates, and alcoholates, and some observations on heats of dilution

Thermochemistry of inorganic solids. 3. Enthalpies of formation of solid metal oxyhalide compounds