Density functional study of reactions of phenoxides with polycarbonate

Density functional calculations with simulated annealing have been used to study the reactions of chains of bisphenol A polycarbonate (BPA-PC) with so dium phenoxide (NaOPh), diphenyl carbonate (DPC), and tetraphenylphosphoniu m phenoxide (PPh4OPh). These calculations extend our work on the reactions of LiOPh, NaOPh, and phenol with the cyclic tetramer of BPA-PC. We study, i n particular, chain growth catalyzed by NaOPh and PPh4OH. The energy barrie rs for reactions with PPh4OPh are somewhat larger than those involving LiOP h and NaOPh, but they are significantly lower than those involving phenol ( HOPh), due in part to the collective rearrangement of phenyl groups in the reacting molecules. We discuss in the Appendix the bonds between alkali met al atoms (Na in the present calculations) and other atoms (here oxygen) tha t are analogous to the more familiar "hydrogen bonds".