NO ON COPPER CLUSTERS

We have investigated the reactivity of Cu-n (n = 15-80) with NO, by us e of a laser-vaporization source, low-pressure reaction cell and photo ionization time-of-flight mass spectrometer. The reactivity was measur ed with the cluster source at room temperature and at liquid-nitrogen temperature, and was found to exhibit similar behavior at both tempera tures, with the exception of a considerably higher reactivity of Cu-16 and Cu-17 at liquid-nitrogen temperature. Apart from this, the reacti vity of Cu-n with NO is very low overall for n = 15-41, whereas the re activity is higher for the larger clusters and is strongly size select ive in the range of n approximate to 40-60, with particularly high rel ative reactivity of Cu-53 and Cu-54. (C) 1998 Elsevier Science B.V. Al l rights reserved.