Ionization potentials of small carbon clusters

Ionization potentials (IP’s) of small carbon clusters (Cn, n=3–6) have been bracketed with an uncertainty of a few tenths of an eV by charge-transfer methods in a Fourier transform ion cyclotron resonance mass spectrometer. Values obtained are compared to previously determined experimental and theoretical values. Several interesting reactions other than charge-transfer were observed between the carbon cluster ions and the charge-transfer reference compounds. The products of these reactions are reported and discussed.