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Kinetics and Mechanism of Metal cation Catalysis in the Hydrolysis of p-Nitrophenyl Picolinate (PNPP)

Cheng S.

Polish Journal of Chemistry

2005

Vol. 79 / nr 5

933-939

The hydrolysis of PNPP was investigated in the presence and absence of Co(II), Cu(II), Ni(II), Zn(II), La(III) at 25°C and ionic strength of 0.1 mol dm-3. The results indicate that the spontaneous hydrolysis of PNPP was catalyzed by hydronium ion, hydroxide ion and water molecule, because of the existence of the pyridium nitrogen, while the metal ion catalyzed hydrolysis of PNPP at zero buffer concentration fulfills the equation: k obsd=K a [H+]+K a (k H[H+]+k 0+k OH K W [H+] showing that the reaction proceeds via nucleophilic attack by external OH- on the metal ion complex of PNPP. The order of catalytic ability of different metal ions was interpreted by the stability of the complex structure relative to the structure of the groundstate intermediate, employing the method devised by Kurz for catalyzed reaction.

Kinetics and Mechanism of Complex Formation between Pentamminesuccinatocobalt(III) and Gallium(III)

Gouri S., Mohanty P.

Polish Journal of Chemistry

2003

Vol. 77 / nr 10

1221-1228

Kinetics and mechanism of decomposition of nitrous oxide over copper catalysts.

Chmielarz L., Kuśtrowski P., Dutkiewicz M., Dziembaj R.

Prace Naukowe Instytutu Chemii i Technologii Nafty i Węgla Politechniki Wrocławskiej. Konferencje

2002

Vol. 10, nr 57

457-462

Three different CuO-containing samples have been studied as catalysts for N2O decomposition. Among the studied samples, hydrotalcite-derived mixed oxides (CuO-MgO-Al2O3) have been found to be the most active catalyst. g-Alumina-supported copper oxide (CuO/Al2O3) was only slightly less active, while the catalytic activity of pure CuO was significantly lower than the rest of the samples. Only a very small amount of chemisorbed N2O has been found on the surface of the catalysts under the reaction conditions. N2 molecules produced from chemisorbed nitrous oxide desorbed directly to the gas phase, while part of oxygen was bonded to the catalyst surface.