Production and Detection of NH Radicals

NH is one of the few species with a triplet electronic ground state isoelectronic 

In practice it turns out to be more complicated to find a clean source for NH(X) than for NH(a) (see below). Nevertheless, the reactions of NH(X) and NH(a) can be studied directly in independent experiments. Detection methods are quite often state-specific, thus there is no need to emphasize that NH(X), NH(a), and NH in other electronic states can be detected characteristically (see p. 25). 

NH can be produced in the gas phase as well as in a liquid or in the solid state (matrices). In a collision-free situation, the excited electronic state has a maximum lifetime, since collisions depopulate the excited states. Thus the situation in the gas phase is significantly 

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