B. Methods

We have carried out preliminary studies on the interaction of singlet methylene with water and methanol at the RHF/3-21G, RHF/6-31G*, MP2/3-21G, and MP2/6-31G* levels of theory. We have also begun to investigate the interaction between dimethylether and methylene at the RHF/3-21G and RHF/6-31G* levels. Work on the interactions of carbomethoxycarbene with water, methanol, and dimethylether is in progress, as are studies of the interactions of methylene and carbomethoxycarbene with 2-methyl-3-buten-2-ol.

For the systems studied, ab initio geometry optimizations were performed along with vibrational frequency calculations to characterize the structures obtained as stationary points. For these ab initio results, and for all the other preliminary results presented in this poster, the effects of basis set superposition error (BSSE) and corrections for zero-point energies (ZPE) have not yet been included. Work is in progress to include these effects. Because these effects have been neglected in our preliminary results, it is possible that some of the more weakly bound systems discussed below may not be bound relative to the separated species once the corrections are included. Neglect of these effects should not, however, change our basic conclusions about the relative stabilities of the complexes.

Most of the preliminary calculations discussed in this poster were performed on workstations available in our department using the GAMESS [7] and Spartan 3.1 [8] ab initio program packages. Some of the larger basis set optimizations at the MP2 level were run on Silicon Graphics Challenge and Power Challenge workstations at the National Center for Supercomputing Applications during the friendly user period in November 1994. The Gaussian 92/DFT program [9] was used on the Challenge and Power Challenge workstations.