Helix-sense-selective free radical polymerization of N-(triphenylmethyl)methacrylamide derivatives

Two novel monomers, N-[(+/-)-(2-fluorophenyl)(4-fluorophenyl)(phenyl)methyllmethacrylamide (2F4FPhMAM) and N-[(4-butyl)triphenylmethyllmethacrylamide (BuTrMAM), were synthesized and polymerized in the presence of (+)- and (-)-menthol as the chiral additive at different temperatures. The obtained polymers, P2F4FPhMAM and PBuTrMAM, are optically active. P2F4FPhMAM is not soluble in common organic solvents and no enantiomer selection was observed in the polymerization of racemic 2F4FPhMAM in the presence of the optically active additive (+)- and (-)-menthols. PBuTrMAM is soluble in THF and chloroform. The circular dichroism spectra of the polymers is similar to that of optically active poly[(triphenylmethyl)methacrylamide] with a prevailing one-handed helicity, suggesting that the present polymers also have a prevailing one-handed helicity. The tacticity of the polymers was estimated from the H-1 NMR spectrum of polymethacrylamide derived in D2SO4. The polymers are almost 100% isotactic. The chiroptical properties of the obtained polymers were studied in detail.