Facile synthesis and high optical activity of poly(1-pentyne)s carrying amino-acid pendant groups

1-Pentynes containing different amino acid moieties and pendant terminal groups [HC C(CH2)(2)CONHC(R')HCO2CH3,whereR'=CH3,CH2CH(CH3)(2),CH2C6H5, and HC C(CH2)(2)CONHC[CH2CH(CH2)(3)]HCO2-(1R,2S,5R)-(+)-menthol} have been designed and synthesized. The polymerizations of the monomers are effected by organorhodium catalysts, giving soluble polymers with moderate molecular weights in satisfactory yields. The structures and properties of the polymers have been characterized and evaluated with infrared, nuclear magnetic resonance, thermogravimetric analysis, circular dichroism, and ultraviolet analyses. All the polymers are thermally stable (>= 300 degrees C) and show strong circular dichroism signals at similar to 310 nm because of the helicity of the polyene backbone. The circular dichroism and ultraviolet absorptions of the polymers can be tuned with a solvent. (c) 2006 Wiley Periodicals, Inc.