Carbon Clusters Studied by Neutralization-Reionization Mass Spectrometry

摘要

The chemistry of C(n) molecules and ions in plasmas (carbon arcs, laser ablation)and in the formation of polynuclear aromatics, diamond films, and soot has been the subject of extensive theoretical and experimental research. In these studies, ab initio calculations of isomeric carbon clusters C(n)O(sup zero) and C(n)+, n = 2-4, yield structures and energies similar to previous reports, although five (not two) C4+ structures have local energy minima. Dissociative ionization of structurally varied precursors was used to prepare C3 and C4 ionic and neutral isomers; however, their mass spectra from collisionally activated dissociation (CAD) and neutralization-reionization (NR) under a wide variety of conditions are indistinguishable, indicating only one isomer or the same mixture of isomers.