Nitrogen kinetics

Mariotti, A., Germon, J.C., Hubert, P., Kaiser, R, Letolle, R., Tardieux, A. and Tardieux, P. 1981 Experimental determination of nitrogen kinetic isotope fractionation some principles illustration for the denitrification and nitrification processes. Plant and Soil 62 413-430. 

The nitrogen kinetic isotope effect for this reaction is 1.034 0.002, which indicates that breaking of the N-O bond occurs in the slow step. ... 

The nitrogen kinetic isotope effect of 1.0197 found using the substrate with the natural abundance of nitrogen isotopes corresponds to an isotope effect of 1.04 for the reaction of the doubly labelled compound. Thus, the nitrogen isotope effects found using two different analytical techniques to measure the isotope effect are in excellent agreement. 

TABLE 7. The incoming nucleophile nitrogen kinetic isotope effects in Menshutkin reactions with various amines in several solvents ... 

TABLE 13. The secondary alpha hydrogen-deuterium and primary nitrogen kinetic isotope effects for the SN2 reaction between sodium thiophenoxide and benzyldimethylphenylammonium nitrate at different ionic strengths in DMF at 0 C... 

The nucleophile in the S.v2 reactions between benzyldimethylphenylammonium nitrate and sodium para-substituted thiophenoxides in methanol at 20 °C (equation 42) can exist as a free thiophenoxide ion or as a solvent-separated ion-pair complex (equation 43)62,63. The secondary alpha deuterium and primary leaving group nitrogen kinetic isotope effects for these Sjv2 reactions were determined to learn how a substituent on the nucleophile affects the structure of the S.v2 transition state for the free ion and ion-pair reactions64. 

TABLE 14. The secondary alpha deuterium kinetic isotope effects and primary leaving group nitrogen kinetic isotope effects for the free ion and ion-pair S 2 reactions between benzyldimethylphenylammonium nitrate and para-substituted thiophenoxide ions in methanol at 20 °C... 

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