AB-INITIO STUDY OF ION TRANSFER IN (H2CO-H-OCH2)+ AND (H2CO-LI-OCH2)+

The equilibrium geometry of (H2CO-H-OCH2)+ is found to have a C(s) structure. A double well potential and a 3.49 kcal/mol barrier are found on the study of energetics of proton transfer at a fixed equilibrium interoxygen distance. The equilibrium geometry of the lithium analogue, (H2CO-Li-OCH2)+, is highly symmetric, D2h. There is no double well in the Li transfer potential until the two oxygen extremes are elongated 1.2 angstrom longer than its equilibrium length. The transition barrier turns out to be 1.72 kcal/mol when R(O-O) increases to 4.84 angstrom. The discrepancies for the above trends between proton and lithium ion in formaldehyde dimer complex are further analyzed.