Computational study of the phenol-formaldehyde reaction: Reactive intermediates and transition states with solvation

CHED 968

Julaunica A. Tigner, julaunica01@yahoo.com and Melissa S. Reeves, mreeves@tuskegee.edu. Department of Chemistry, Tuskegee University, Armstrong Hall Rm 102, Tuskegee, AL 36088
The reaction of phenol with formaldehyde produces a resin with many industrial uses due to its mechanical strength and heat resistance. The initial reaction between phenol and formaldehyde can be carried out under basic aqueous conditions, producing a resole. The reaction at the ortho position is known to occur faster since there are two ortho sites, but the para attack has a lower activation energy. We will present reactive intermediates and correlated transition states for the para and ortho attacks of formaldehyde on phenol. These results required the presence of both a solvent field and an explicit water molecule at the B3LYP/6-311+G(d,p) level of theory. However using MPW1PW91/6-311+G(d,p) for the para attack, we were able to obtain a reactive intermediate and transition state with the solvent field alone. The para transition state has a lower activation energy than the ortho for all levels of theory studied.