کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5190798 | 1381218 | 2006 | 7 صفحه PDF | دانلود رایگان |
A glutamic acid- and azobenzene-containing novel N-propargylamide, (S)-CHCCH2NHCOCH(CH2CH2CO2CH2C6H5)NHCO2CH2CH2-p-C6H4NNC6H5 (1) was synthesized and polymerized with (nbd)Rh+[η6-C6H5Bâ(C6H5)3] as a catalyst to obtain the corresponding polymer [poly(1)] with the moderate number-average molecular weight of 12,200 in 93% yield. The chiroptical studies revealed that poly(1) took a helical structure in THF, CHCl3, CH2Cl2 and toluene. Poly(1) underwent solvent and heat-driven helix-helix transition. The trans-azobenzene of the side chain isomerized into cis upon UV-irradiation, accompanying decrease in helicity. The cis-azobenzene moiety reisomerized into trans upon visible-light irradiation, while the polymer did not recover the original helicity.
Journal: Polymer - Volume 47, Issue 8, 5 April 2006, Pages 2596-2602