NO on copper clusters

We have investigated the reactivity of Cun (n=15–80) with NO, by use of a laser-vaporization source, low-pressure reaction cell and photoionization time-of-flight mass spectrometer. The reactivity was measured with the cluster source at room temperature and at liquid-nitrogen temperature, and was found to exhibit similar behavior at both temperatures, with the exception of a considerably higher reactivity of Cu16 and Cu17 at liquid-nitrogen temperature. Apart from this, the reactivity of Cun with NO is very low overall for n=15–41, whereas the reactivity is higher for the larger clusters and is strongly size selective in the range of n≈40–60, with particularly high relative reactivity of Cu53 and Cu54.