Theoretical studies of the interactions of singlet carbenes with water and alcohols

Results are presented from ab initio calculations which explore the interactions of singlet carbenes with water and alcohols. The carbenes investigated include methylene and carbomethoxycarbene. A number of different minima on the potential energy surfaces have been located and characterized. These minima correspond to oxonium ylide-type structures as well as to hydrogen-bonded structures. Equilibrium geometries, binding energies, and vibrational frequencies have been determined. We also report on the results of preliminary studies of the geometries and energetics of transition states for rearrangement of the oxonium ylides to alcohols or ethers. Calculations were performed at levels of theory ranging from HF/3-21G to MP2/6-311G**, and include zero-point energy corrections, as well as basis set superposition error corrections.