SEARCHING FOR THE YLIDE STRUCTURE - AN AB-INITIO STUDY OF THE H2O...CCL2 COMPLEX

The potential energy surface (PES) for the H2O...CCl2 complex has been investigated at the self-consistent field level with a DZP basis set in order to search for stationary points and to verify the possible fo rmation of an ylide species. Six stationary points were located on the PES, being one minimum, three first-order transition sates (TS) and t wo second-order TS structures. A stable ylide species was not found, a nd an explanation for this is given based on electrostatic grounds, Th e unique minimum corresponds to an H-bond structure, with a dissociati on energy of 845.5 cm(-1), calculated including zero point energy corr ection, a more extended basis set, electron correlation effects at the MP2 level and taking into account basis set superposition errors empl oying the counterpoise method.