Conference Abstracts 387 Its strategic position, the proximity to one of the most important hospitals of Rome, the presence of several important facilities, suggested this CNR Research Area as the best location for the installation of the Scanditronix MC-40 cyclotron. Notwithstanding that this powerful accelerator can be applied to several scientific fields, the first approach to its installation was essentially to satisfy the requirements for the production of short-live radioisotopes and their use in nuclear chemistry and medicine. In order to realize a self consisting structure, the installation project described all the facilities necessary for the management of the accelerator. Particular attention was devoted to the safety system in the main building and taking into account the recent directives given by the official bodies. The main building, containing the cyclotron, the beam-lines and the irradiation rooms, is well connected with the radiochemistry laboratories using, whenever possible, the most appropriate automatic devices for the transport of radioactive products or irradiated targets. Adjacent to the main building, a small day-hospital for nuclear medicine, equipped of a PET tomographic instrument, will be established. Tritium-induced 19F-NMR-Shifts on l,l, 1,4,4,4-Hexafluoro-2,3-ditritio-2-butene G. ANGELINI,’ G. LILLA,’ C. SPARAPANI,’ 0. URSINI,’ E. ROSSL2 A. L. SEGRE,3 M. A. McALLISTER4 and T. T. TIDWELL4 ‘Istituto di Chimica Nucleare de1 CNR Area della Ricerca di Roma, 2Servizio N.M.R. Area della Ricerca di Roma, Roma, Italy, ‘Istituto Strutturistica Chimica “Giordano Giacomello” de1 CNR Area della Ricerca di Roma, Roma, Italy and 4Department of Chemistry, Scarborough Campus, University of Toronto, Canada M5S IA1 Recent theoretical studies have elucidated the potential energy surfaces for the CF,CH:, CH,FCH: and CF: C=CH, ions and have suggested that intramolecular fluoride transfers via bridged fluoronium ions may be viable processes for these ions. Several gas phase investigations have provided evidence for fluorine isomerization, although some of these results have instead been interpreted by an elimination-readdition pathway. A further test of the occurrence of this process in both gas and liquid phases at atmospheric or higher pressure would be the “tritium nuclear decay technique”. In this communication the synthesis of 1 zyxwvutsrqponmlkjihgfedcbaZYXWVUTSRQPONMLKJIHG ,l, 1,4,4,4-hexafluoro-2,3-ditritio-2-butene by partial tritium addition to hexafluoro-2-butyne, at no carrier added level is reported. The quantitative evaluation of the isotopic distribution between the mono and di-tritiated products has been carried out using GC/MS techniques observing the [M-F]+ fragmentation peak characteristic for every butene in the mixture. Confirmation of these results came from the ‘H- and 19F-NMR analyses of the butenes. The 3H-NMR spectrum of butenes gave a main broad multiplet. The 19F-NMR spectra were useful as a measure of the ratio between mono and ditritiated compounds. Our results give the first evidence for a strong tritium isotope induced shift in 19F-NMR, thus allowing a good quantitative analysis. An Ab Initio Study of the Structure and Stability of (C, ,H, ,Ge)+ PAOLA ANTONIOTTI,’ PAOLA BENZ&’ PAOLO VOLPE’ and FELICE GRANDINETTI’ ‘Dipartimento di Chimica Generale ed Organica Applicata, Universita di Torino, Corso Massimo d’Azeglio 48, 10125 Torino, Italy and *Istituto di Chimica Nucleare de1 CNR Area della Ricerca di Roma, C.P. 10, 00016 Monterotondo Stazione, Roma, Italy Various (C2,H,,Ge)+ stable isomers have been identified on the corresponding SCF 3-21G* potential energy surface. Twelve distinct structures have been characterized, and their relative stability has been evaluated at the correlated theoretical MP2 levels, with double-zeta quality base states. Several analogies exist with the previously described (C3,H5)+ species, although significant differences can be pointed out. Distinct stable