Pyrene functionalized side chain alanine and histidine containing copolyacrylates prepared by free radical copolymerization

Abstract

An optically active copolyacrylate, poly(N-acryloyl-L-alanine-co-N-acryloyl-L-histidine), is prepared by classical radical copolymerization of N-acryloyl-L-alanine and N-acryloyl-L-histidine, and further chemically modified with 1-pyrene-methanol. The structures of the synthesized compounds are confirmed by spectral analysis (FTIR, 1 H/ 13 C-NMR, UV, fluorescence spectroscopy), thermal methods, and molecular weight measurements. Also, their optical activity is studied using circular dichroism (CD) spectroscopy and optical rotation measurements. The specific rotation values reveal that the direction of rotation of the parent copolymer is dictated by the monomer containing L-alanine. CD data suggest negative and positive Cotton effects regarding the monomers with amino acids. In the case of the unmodified copolymer it is noted the changes of ellipticity values with increasing pH while the random-coil conformation is preserved, which makes it suitable as a pH-responsive system. Photochemical and photophysical investigations reveal that the pyrene-functionalized chiroptical copolyacrylate can be used as a fluorescent chemosensor for the detection of nitro-derivatives in organic media.

Synthesis of random copolymers of styrene and arylamino substituted styrenes and their sensitivities towards nitroaromatics

“…In particular, fluorescence sensors have gained great attention because of their low cost, high response speed, remoted-control detection, and extremely high sensitivity. 8,9,14 Due to their unique photophysical properties, fluorescent polymers have attracted significant attention from researchers over the past two decades, as promising sensing elements for portable explosive detectors [15][16][17][18][19][20][21][22][23][24][25] and some biosensing applications. 26,27 Pyrene derivatives and related polycyclic aromatic hydrocarbons are considered to be appropriate fluorophores due to their chemical stability and high quantum yields.…”

“…Due to their unique photophysical properties, fluorescent polymers have attracted significant attention from researchers over the past two decades, as promising sensing elements for portable explosive detectors 15–25 and some biosensing applications 26,27 …”