Theoretical characterization of the excited-state structures and properties of phenol and its one-water complex

The structures and properties of phenol and its complex were characterized at the Hartree-Fock (HF), the second-order Moller-Plesset perturbation theo ry (MP2), and complete active space self-consistent field (CASSCF) levels f or the ground state (S-0) and at the configuration interaction with single excitation (CIS) and CASSCF levels for the excited electronic state (S-1). The intermolecular interaction has little influence on the structures of ph enol and water. However, a significant change is found in the properties up on complex, and this has been discussed in detail. A comparison with the ex perimental findings shows that the present calculations provide a good desc ription of the nature of phenol and its complex in S-0 and S-1. (C) 2000 Am erican Institute of Physics. [S0021-9606(00)30803-0].