INTRIGUING STRUCTURES AND STABILITIES OF C2LIX SPECIES (X=6, 8, 10, 12)

A high-level ab initio quantum chemical study of lithiocarbons with th e formulae C2Lix (x = 6, 8, 10 and 12) has yielded provocative results . The structures predicted for these systems are intriguing and do not follow normal chemical rules. Each compound is predicted to contain a triply bonded C-2(2-) unit and various cationic Li clusters which act as polydentate ligands. Little direct C - Li covalent bonding is pres ent. Calculated vibrational frequencies show that the lowest-energy is omer for each compound is a true minimum. All species have substantial thermodynamic stability towards loss of Li-2. Binding energies have b een evaluated at levels of theory up to QCISD(T)/DZ(2)P and range from 102 kJ/mol for C2Li10 to 170 kJ/mol for C2Li6. Predicted vibrational frequencies and their IR intensities are reported.