THE NATURE OF C10H2-SPECTRA OF POLYNUCLEAR AROMATIC-HYDROCARBONS( IN MASS)

Ab initio and density functional theory (DFT) calculations have been p erformed to determine the heats of reaction for the process C16H10+ -- > C10H2+ that takes place in an ion trap mass spectrometer. Comparison s have been made with the experimental and derived data available for this process. The theoretical values at the DFT level verify the exper imental heats of reaction within 0.4-0.8 eV. Furthermore, the structur e of the product ion, C10H2+, has been investigated. Several structure s have been proposed, and the ab initio and DFT geometry optimizations and frequency calculations have been performed to determine the most stable species. At the level of theory and the approximations that wer e used in this work, the linear form of C10H2+ is the most stable spec ies of three different geometries considered. (C) 1998 Elsevier Scienc e B.V.