Ground state gas and solution phase conformational dynamics of polar processes: Furfural systems

The conductorlike continuum solvation model, modified for ab initio in the quantum chemistry program GAMESS, implemented at the Moller-Plesset Order 2 (MP2) level of theory has been applied to a group of push-pull pyrrole systems to illustrate the effects of donor/acceptor and solvation on the stability and energetics of such systems. The most accurate theoretical gas and solution phase data to date has been presented for the parent furan-2-carbaldehyde (furfural) system, and predictions made for three additional analogues, thiophene-2-carbaldehyde, pyrrole-2-carbaldehyde, and, cyclopentadiene-1-carbaldehyde. Solvent effects on internal rotational barriers in all systems were evaluated over six different values of dielectric, using the new method. Calculated electrostatic energies are shown to be highly sensitive to level of theory incorporated. (C) 2000 American Institute of Physics. [S0021-9606(00)52841-4].