Formations and studies of binary cluster anions of XnSm (X=C, Si, Ge)

<正> A series of cluster anions, XnSm- (X=C, Si, Ge), are observed on a home-made time-of-flight mass spectrometer by laser ablation of the sample, mixture of sulfur with carbon, silicon, or germanium powder. For X=C, the cluster anions with m = 2 have higher ion intensities; for X=Si, those with m = 2n + 4 have higher intensities; for X=Ge, those of m = 2n + 2 are higher. After analyzing the results of experiments, the possible structures of these cluster anions are discussed and sug-