Novel 9-proparylcarbazole monomers containing amino acid moieties

2-N-(tert-butoxycarbonyl)-L-alanine-9-proparylcarbazole ester (1)

2-N-(tert-butoxycarbonyl)-L-O-cyclohexyl-L-glutamic acid-9-proparylcarbazole ester (2) and 2-N-(tert-butoxycarbonyl)-L-phenylalanine-9-proparylcarbazole ester (3) were synthesized and polymerized with (nbd)Rh+[η6-C6H5B–(C6H5)3] to give the corresponding polymers with number-average molecular weights ranging from 7050 to 10500 in 70%-86% yields. The polymers were completely soluble in toluene

CHCl3

CH2Cl2

THF and DMSO

but insoluble in hexane

diethyl ether and MeOH. The specific rotation studies revealed that poly(1)-(3) do not took predominantly one-handed helical structures in the solvents although they possess chiral groups. The polymers emitted fluorescence in 0.40%–2.35% quantum yields. The cyclic voltammograms of the polymers indicated that the polymers exhibited electrochemical properties.