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n-Alkenes and dihydrogen were obtained from n-alkanes by photocatalysis using carbonyl(ch1oro)phosphinerhodium complexes; the rate of alkane dehydrogenation was the same as that of propan-2-01 dehydrogenation under the same photocatalytic reaction conditions.

52system. For DsL << DCuKTSM2 the lower limit for the translational diffusion coefficient for CuKTSM2 is equal to (60 -95) X lo-* cm2/s. Because the translational diffusion constant for 16-SASL at that temperature in DMPC is about 5 X the assumption that DsL Abstract: Nickel species contained in Y-type zeolite have been characterized by an EXAFS technique at each stage of catalyst preparation. When nickel ions were incorporated into the zeolite by aqueous ion exchange, a kind of "solution-like" hydrated state with Ni-O = 2.06 8, was suggested from the EXAFS analysis. After calcination, the nickel ions, surrounded by an average of 3.6 oxygen atoms with Ni-0 = 2.05 8,, scattered around the exchangeable sites with unsaturated coordination. According to the EXAFS and ESCA (electron spectroscopy for chemical analysis) results, the nickel ions in this state could not be reduced completely by hydrogen. On the contrary, a different behavior of hydrogen reduction was observed after treatment of the hydrated-nickel zeolite with an aqueous sodium hydroxide solution. A new nickel hydroxide oligomer with Ni-0 = 2.06 8, was formed in the supercage by this treatment. Moreover, calcination of this alkali-treated zeolite under oxygen atmosphere gave another new product containing nickel atoms with 3.5 oxygen neighbors at 2.08 8, and three second-nearest nickel neighbors at 2.99 8,. These oligomeric nickel-oxide clusters are certainly responsible for the high catalytic activity in CO oxidation. Hydrogen reduction of the small oxide clusters gave the zeolite catalyst which has an excellent activity for benzene hydrogenation. This material was confirmed to contain finely dispersed metallic nickel by the radial distribution function derived from the EXAFS spectrum.Zeolites are crystalline aluminosilicates consisting of threedimensional arrays of SiO, and AIO, tetrahedra. The void space enclosed within the unit is called the sodalite cage,! whereas a larger void space, called the supercage, is formed by linking sodalite units by hexagonal prisms. Windows 7.4 A in diameter (8) Morrison, T. I.; Iton, L. E.; Shenoy, G. K.; Stucky, G. D.; Suib, S. L.

A chemical heat pump for upgrading low‐level thermal energy has been proposed by adopting a reversible organic reaction couple, endothermic liquid‐phase dehydrogenation of 2–propanol at low temperature and exothermic gas‐phase hydrogenation of acetone at high temperature, where thermodynamical work is done by separating condensed 2–propanol from the gaseous mixture of 2–propanol, acetone and hydrogen in a fractionation column. In the system constitution of the continuous type, the overhead vapour of the fractionation column is fed through the heat exchanger into the exothermic reactor, where acetone and hydrogen in excess are changed at 200°C into the equilibrium mixture, from which condensable 2–propanol is separated in the column by cooling at 30°C. The reverse reaction of 2–propanol decomposition into acetone and hydrogen proceeds in the endothermic reactor, i.e. the reboiler of the column, absorbing heat at 80°C. On the contrary, acetone and hydrogen in the overhead vapour of the fractionation column are stored at 30°C as liquid and metal hydride, respectively, in the system constitution of the storage type; when necessary, metal hydride is decomposed by heating at 80°C, with hydrogen at high pressure evolved and fed through the heat exchanger into the exothermic reactor, giving the equilibrium mixture at high pressure and temperature. Product condensates are transferred through a valve into the fractionation column in order to separate 2–propanol and acetone, the former of which is dehydrogenated in the endothermic liquid‐phase reactor, regenerating acetone and hydrogen at 80°C and atmospheric pressure. Energy efficiencies were evaluated for the system constitutions of both the continuous and storage types; the 80°C heat supplied was convertible into the 200°C heat continuously at the enthalpy efficiency or coefficient of performance (COP) of 0·36 in the former, whereas the 270°C heat was obtainable with the aid of metal hydride from the same heat source at COP of 0·21 in the latter.

The nuclear magnetic resonances of 35CI and 37C1 in a number of simple chlorine compounds were measured. Since both the paramagnetic contribution for chemical shift and the quadrupole coupling constant of the atom are determined by the same radial distribution of the electron, a linear relationship between the chemical shifts and the quadrupole coupling constants may be expected for compounds for which the electronic excitation energies are comparable. This was demonstrated for the series of chloro-substituted methanes. By graphical extrapolation the absolute chemical shift of the reference compound, NaCl aqueous solution, was obtained. The chemical shift of CI-aq. ion can be interpreted as the sum of the diamagnetic shift of C1-spherical ion and a paramagnetic shift resulting from its hydration. The experimental and theoretical values of the paramagnetic chemical shift of the Clr molecule were -2.06 X and -2.17 X respectively. Paramagnetic chemical shifts and line widths of resonance spectraof simple chlorine compoundsare discussed, as well as the feasibility of high-resolution chlorine resonances for structural applications.