FT-ICRによるシリコンクラスターイオン (Si+n, n=10-30) とエチレン分子の化学反応特性

Mass-selected silicon cluster ions were levitated in a Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer and monitored during chemisorption reaction with ethylene (C2H4). Through measurements of “time-dependency” of this reaction process, large change of the reactivity depending on the number of absorbed ethylene was observed, in addition to the strong dependency to silicon cluster size. From Si+15 to Si+18 shows a special stability of SixE+y when x+y=19, such as Si15E+4. The large decrease in the reactivity of Si+n was observed due to the contamination of hydrogen atom to Si+n. Rate constants for the adsorption of the first C2H4 molecules on Si+n were estimated. The reaction kinetics data suggest that structural isomers are present for all clusters except Si+14 in the size range investigated.