Structures, Energetics and Fragmentation Pathways of C\u3cem\u3e\u3csub\u3en\u3c/sub\u3e\u3c/em\u3eH\u3csub\u3e2\u3c/sub\u3e\u3csup\u3e2+\u3c/sup\u3e Carbodications

Potential energy curves have been calculated for CnH22+ (n = 2−9) ions and results have been compared with data on unimolecular charge-separation reactions obtained by Rabrenovi{\\u27{c}} and Beynon. Geometry-optimized, minimum energy, linear CnH22+ structures have been computed for ground and low-lying excited states. These carbodications exist in stable configurations with well depths greater than 3 eV. Decomposition pathways into singly charged fragment ions lead to products with computed kinetic energies in excess of 1 eV. A high degree of correlation exists between experimental information and results computed for linear CnH22+ structures having hydrogen atoms on each end. The exception involves C4H22+ reactions where a low-lying doubly charged isomer must be invoked to rationalize the experimental data