Radical Polymerization of 5-(4′-Acrylamidophenyl)-10,15,20-triphenylporphine and 5-(4′-Methacrylamidophenyl)-10,15,20-triphenylporphine

High polymers were obtained by the radical polymerization of 5-(4′-acrylamidophenyl)-10,15,20-triphenylporphine (AATPP) and 5-(4′-methacrylamidophenyl)-10,15,20-triphenylporphine (MATPP) in which vinyl groups bind to a tetraphenylporphyrin (TPP) with amide linkage, using 2,2′-azobis(isobutyronitrile) as an initiator at 60°C. Monomer reactivity ratios were determined by the copolymerization of AATPP or MATPP (M1) with styrene (M2) as r1=0.065±0.045 and r2=0.67±0.07, or r1=0.14±0.01 and r2=0.72±0.01, respectively. Q and e were 0.28 and 1.41 for AATPP and 0.39 and 0.79 for MATPP, respectively based on r1 and r2 values. Rate constants of the addition of diphenylphosphinoyl radicals (Ph2\\dotP=O), generated by the photolysis of 2,4,6-trimethylbenzoyl diphenylphosphine oxide (TMDPO), to amide-TPP monomers were determined by time-resolved electron spin resonance (ESR) spectroscopy. The rate constants of the reaction of the amide-TPP monomers (∼1.3×106 s−1M−1 for AATPP and ∼0.5×106 s−1M−1 for MATPP) were much smaller than that of N-phenylacrylamide (∼4.2×107 s−1M−1) or N-phenylmethacrylamide (∼1.4×108 s−1M−1), probably due to decrease in resonance stabilization due to a steric hindrance of bulky TPP moiety.