27A1NMR

A1NMR spectroscopy (234). The exchange reactions are also fast in ether, but about 104 times slower in pyridine. In the latter solvent, a mixture of trimethylaluminum and triethylaluminum requires about 4 hours at 40° C for a 50% equilibration (207). From proton NMR measurements in pyridine, the following equilibrium constants were found for the exchange of phenyl with methyl groups (209),... 

Matthias, A., Maurer, M., and Parlar, H. (2003). Comparative aluminium speciation and quantification in soil solutions of two different forest ecosystems by 27A1NMR. Fresenius Environ. Bull. 12,1263-1275. 

AI2O3 were prepared by precipitating alumina onto silica gel, followed by hydrothermal treatment. These materials were characterized by 27A1NMR and ESCA and evaluated in gas oil cracking. NMR revealed the presence of tetrahedral, pentacoordinated and octahedral A1 species in the steamed Si02 - AI2O3 samples with 27 and 13% AI2O3. 

McCormick AV, Bell AT, Radke CJ (1986) Application of 29Si and 27A1NMR to determine the distribution of anions in sodium silicate and sodium alumino-silicate solutions. In Murakami Y, lijima A, Ward JW (eds) Proceedings of the 7th international zeolite conference. Elsevier, Amsterdam, p 247... 

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