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31.
Wagner SR Hinshaw DA Ong RA Snyder A Abrams G Adolphsen CE Akerlof C Alexander JP Alvarez M Amidei D Baden AR Ballam J Barish BC Barklow T Barnett BA Bartelt J Blockus D Bonvicini G Boyarski A Boyer J Brabson B Breakstone A Brom JM Bulos F Burchat PR Burke DL Butler F Calvino F Cence RJ Chapman J Cords D Coupal DP DeStaebler HC Dorfan DE Dorfan JM Drell PS Feldman GJ Fernandez E Field RC Ford WT Fordham C Frey R Fujino D Gan KK Gidal G Gladney L Glanzman T Gold MS Goldhaber G Green A 《Physical review letters》1990,64(10):1095-1098
32.
H. v. Brandis F. E. Wagner J. A. Sawicki K. Marcinkowska J. H. Rolston 《Hyperfine Interactions》1990,57(1-4):2127-2131
The state of iridium on Pt?Ir catalysts prepared by impregnation of amorphous silica with H2IrCl6 and H2PtCl6 was studied by193Ir Mössbauer spectroscopy after different steps of preparation. The Ir is adsorbed in its trivalent state, presumably as [IrCl6]3?. Calcination in air at 450°C converts this to IrO2. The metallic clusters formed by subsequent reduction in H2 at 200°C show a strong tendency towards segregation of Ir and Pt and re-oxidize partially when exposed to air at ambient temperature. In both respects the behaviour is similar to that of samples prepared by co-exchange from [Ir(NH3)5Cl]Cl2 and Pt(NH3)4Cl2. H2O. 相似文献
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Mathiazhagan C Molzon WR Cousins RD Konigsberg J Kubic J Melese P Rubin P Slater WE Wagner D Hart GW Kinnison WW Lee DM McKee RJ Milner EC Sanders GH Ziock HJ Arisaka K Knibbe P Urheim J Axelrod S Biery KA Irwin GM Lang K Margulies J Ouimette DA Ritchie JL Trang QH Wojcicki SG Auerbach LB Buchholz P Highland VL McFarlane WK Sivertz M Chapman MD Eckhause M Ginkel JF Hancock AD Joyce D Kane JR Kenney CJ Vulcan WF Welsh RE Whyley RJ Winter RG 《Physical review letters》1989,63(20):2181-2184
37.
Summary The complexestrans-[Ru(NH3)4(H2O)PPh3](PF6)2 and [Ru(NH3)5L](PF6)2, (L=AsPh3 or SbPh3) have been isolated and characterized by microanalysis, cyclic voltammetry and ultraviolet-visible spectroscopy. The specific rate constants for the aquation of [Ru(NH3)5L]2+ totrans-[Ru(NH3)4L(H2O)]2+ are (2.5±0.1)×10–5s–1 and (1.8±0.1)×10–5s–1 for L=AsPh3 and SbPh3, respectively, at 25.0±0.1°C; =0.10 mol dm–3, NaO2CCF3. Under the same conditions, the second-order rate constants for the substitution of water intrans-[Ru(NH3)4(H2O)L]2+ by isonicotinamide (isn) are 1.2±0.1, (6.3±0.3)×10–2 and (3.8±0.2)×10–2
m
–1s–1 for L=PPh3, AsPh3, and SbPh3, respectively, suggesting that the order of decreasingtrans-effect is: PPh3AsPh3>SbPh3. The formation constants for thetrans-[Ru(NH3)4L(isn)]2+ complexes are 75±3, (1.40±0.01)×103 and (1.80±0.02)×103M–1 for L=PPh3, AsPh3, and SbPh3, respectively, suggesting that the order of increasingtrans-influence is: SbPh33PPh3. 相似文献
38.
BIOLOGICAL ACTIVITIES OF PHTHALOCYANINES-X. SYNTHESES AND ANALYSES OF SULFONATED PHTHALOCYANINES 总被引:5,自引:0,他引:5
Hasrat Ali Réjean Langlois J. Richard Wagner Nicole Brasseur Benoit Paquette Johan E. VAN Lier 《Photochemistry and photobiology》1988,47(5):713-717
Abstract— Synthetic methods to obtain selectively sulfonated metallo phthalocyanines are compared. Both condensation and direct sulfonation procedures lead to mixtures of mono- to tetrasulfonated products which are resolved by reverse phase liquid chromatography in buffered aqueous-methanol. The proportion of sulfonated derivatives is examined as a function of the starting reagents in the case of the condensation method, and as a function of the temperature and reaction time in the case of the direct sulfonation procedure. The number of sulfonate groups per phthalocyanine molecule is determined by oxidative degradation of the phthalocyanine ring followed by quantitative chromatographic analysis of the sulfophthalamide and phthalamide fragments. 相似文献
39.
Azidomethyl–polystyrene, obtained by nucleophilic substitution of chloromethyl–polystyrene, undergoes a Schmidt rearrangement when treated with trifluoromethanesulfonic acid, affording amino–polystyrene. To assess its loading and reactivity the resin is used as a support for the preparation of triazene-linked amine. 相似文献
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