Abstract: Study on the Fast Atom Bombardment Mass Spectra of Trinuclear Cobalt ClusterCai Yuanba;Peng Jinhai;Dai Liang;Xu Yongjin;Kang Beisheng (Fujian Institute of Research on the Structure of Matter,Chinese Scademy of Sciences,Fuzhou 350002,China) Abstract:The fast atom bombardment mass spectra (FABMS)of trinuclear cobalt cluster are reported. In the light of the spectra the fragmentation pathways are proposed,and several novel ion fragments are observed,which posses 16 atom mass units small than that from normal unimolecular decomposition reaction, exactly corresponding to the result of replacement of a sulfur atom by an oxygen atom in and Co2 (C6H4S2)2. In addition there is also an ion peak of 16 atom mass units larger than m/z 1219 (3% ) corresponding to It is interested for the posibility of new mode of reaction,and simply implies that the sample is sensitive to oxygen.Keywords:trinuclear cobalt cluster,FABMS,fragmentation pathway