NH2 Radicals in Condensed Media

Most of the NH2 studies were done in the gas phase however, NH2 radicals can also be produced and studied in condensed media, in aqueous solutions [1 to 11], in liquid ammonia [12 to 16], in low-temperature matrices [17 to 27], or in salts at room temperature [28]. 

In aqueous solutions NH2 radicals are produced by the redox reaction between Ti ions [1] or ions [5] and hydroxylamine in acid media 

Relative reactivities of NH2 radicals towards a substrate (SH) and towards Ti ions were obtained by comparing the rates of 

As substrates, the alcohols CH3(CH2)nOH, where n is in the range 0 to 4 (i.e. methanol to pentanol), were measured. The reactivity of the alcohols Increases with increasing n [4]. The reactivity of NH2 radicals towards amines increases In the same way with Increasing n in the substances CH3(CH2)nNH3, with n ranging from 2 to 7 [4]. 

The reactions in the liquid phase are in many respect very similar to the gas phase reactions at their high-pressure limit. Therefore, addition on a double bond Is expected, and the amine radical thus formed is stabilized by collisions. This was observed directly for the reaction of NH2 with maleic acid via 

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