DIMETHYLCARBENE, ITS RADICAL-CATION AND DICATION

The dimethylcarbene radical cation, (CH3)(2)C.+, has been generated in the gas phase. Experimental identification was achieved by charge str ipping mass spectrometry whereby the stable dimethylcarbene dication, (CK3)(2)C2+, is observed. Electron impact appearance energy measuremen ts and G2 ab initio molecular orbital calculations have been used to i nvestigate the thermochemistry of the dimethylcarbene radical cation. The carbene radical cation is calculated to lie 84 kJ mol(-1) above th e propene radical cation and to be separated from it by a barrier of 3 5 kJ mol(-1).