Experimental and computational studies of bulk polymerization of styrene in the presence of N-(O-(1-phenylmethyl)oxy) phthalimide or cyclohexanone-O-(1-phenylmethyl)oxime

Syntheses of potential initiators N-(O-(1-phenylethyl)oxy)phthalimide, N-(O -(1-phenylmethyl)oxy)phthalimide (POP), cyclohexanone-O-(1-phenylethyl)oxim e, and cyclohexanone-O-(1-phenylmethyl)oxime (CHPO) are described. Bulk pol ymerization of styrene in the presence of POP or CHPO and molecular weight measurement by GPC indicate that the polymerization is not a living process . Ab initio calculations show that the C-O or O-N bond cleavage energies of POP and CHPO are close to each other (3: C-O: 46.4, O-N: 47.3 kcal/mol; 1: C-O: 46.9, O-N: 63.0 kcal/mol) and much higher than the similar analogs of 2,2,6,6-tetramethylpiperidinyloxy (TEMPO) (C-O: 20.9, O-N: 34.4 kcal/mol). The similar CO and O-N bond cleavage energies of the synthesized initiator s (POP/CHPO) indicate two possible cleavage pathways and may explain the no n-living nature of the polymerization. These results may be helpful in find ing future reversible terminator compounds for living polymerization.