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Au@poly( N ‐propargylamide) Nanoparticles: Preparation and Chiral Recognition
Author(s) -
Zhang Chaohong,
Song Ci,
Yang Wantai,
Deng Jianping
Publication year - 2013
Publication title -
macromolecular rapid communications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.348
H-Index - 154
eISSN - 1521-3927
pISSN - 1022-1336
DOI - 10.1002/marc.201300355
Subject(s) - monomer , circular dichroism , nanoparticle , copolymer , polyacetylene , materials science , polymer chemistry , fourier transform infrared spectroscopy , cotton effect , absorption spectroscopy , proton nmr , colloidal gold , spectroscopy , absorption (acoustics) , chemistry , crystallography , polymer , stereochemistry , chemical engineering , nanotechnology , physics , quantum mechanics , engineering , composite material
This communication reports the first gold nanoparticles (NPs) chirally functionalized with optically active helical substituted polyacetylene (the resulting hybrid particles are defined as Au@PPA NPs). The novel nanoparticles consist of gold as core and optically active helical poly( N ‐propargylamide) as shell and show considerable optical activity derived from helical poly( N ‐propargylamide) chains with predominantly one‐handed screw sense. The Au@PPA NPs are prepared by a three‐step approach: i) a thiol‐containing N ‐propargylamide monomer [M th , HC≡CCH 2 NHCO(CH 2 ) 10 SH] is synthesized and characterized with FTIR and 1 HNMR spectroscopy and elemental analysis; ii) a copolymer (poly(M th ‐ co ‐M ch )) was prepared by starting from monomer M th and another chiral N ‐propargylamide monomer (M ch ); poly(M th ‐ co ‐M ch ) formed helical conformations and showed optical activities; and, iii) Au@PPA NPs are prepared from hydrogen tetrachloroaurate (III) and poly(M th ‐ co ‐M ch ) through a one‐spot procedure by using LiBH 4 as reducing agent. The as‐obtained hybrid nanoparticles are characterized by FTIR spectroscopy, TEM, UV‐vis absorption and circular dichroism (CD) techniques. UV‐vis and CD measurements demonstrated the remarkable optical activity of the Au@PPA NPs. More interestingly, the Au@PPA NPs show much stronger UV‐vis and CD sigals when compared to the corresponding orginal helical copolymer, poly(M th ‐ co ‐M ch ). The chiral hybrid nanoparticles demonstrate different absorption toward (R)‐(+)‐ and (S)‐(−)‐1‐phenylethylamines, preferentially adsorbing the (S)‐isomer.