The Mass Spectrometric Detection of Dimers of Nitric Oxide and Other Polyatomic Molecules

摘要

Previous studies with Ar (see AD-637 177) have shown that the empirical extrapolation of the Ar dimer mole fraction to zero orifice size gives a value quite close to that obtained from equilibrium calculations. Such a result with Ar led to the hope that the other weakly interacting gases could be sampled at high pressures (where higher-cluster equilibria are favored), with extrapolation against orifice size being used to correct for nucleation effects during expansion. However, the polyatomic gases appear to behave quite differently. This behavior is discussed in terms of possible reasons for the low observed mole fractions of polyatomic dimer. The support that the NO results give for Fontijn and Rosner's postulate that clusters are involved in the anomalous (NO) x +O reaction rates is then briefly mentioned.