Chemistry - A European Journal p. 8861 - 8874 (2013)
Update date:2022-08-05
Topics:
Fatás, Paola
Bachl, Jürgen
Oehm, Stefan
Jiménez, Ana I.
Cativiela, Carlos
Díaz Díaz, David
This work demonstrates that the incorporation of azobenzene residues into the side chain of low-molecular-weight peptides can modulate their self-assembly process in organic solvents leading to the formation of stimuli responsive physical organogels. The major driving forces for the gelation process are hydrogen bonding and π-π interactions, which can be triggered either by thermal or ultrasound external stimuli, affording materials having virtually the same properties. In addition, a predictive model for gelation of polar protic solvent was developed by using Kamlet-Taft solvent parameters and experimental data. The obtained viscoelastic materials exhibited interconnected multistimuli responsive behaviors including thermal-, photo-, chemo- and mechanical responses. All of them displayed thermoreversability with gel-to-sol transition temperatures established between 33-80 °C and gelation times from minutes to several hours. Structure-property relationship studies of a designed peptide library have demonstrated that the presence and position of the azobenzene residue can be operated as a versatile regulator to reduce the critical gelation concentration and enhance both the thermal stability and mechanical strength of the gels, as demonstrated by comparative dynamic rheology. The presence of N-Boc protecting group in the peptides showed also a remarkable effect on the formation and properties of the gels. Despite numerous examples of peptide-based gelators known in the literature, this is the first time in which low-molecular-weight peptides bearing side chain azobenzene units are used for the synthesis of "intelligent" supramolecular organogels. Compared with other approaches, this strategy is advantageous in terms of structural flexibility since it is compatible with a free, unprotected amino terminus and allows placement of the chromophore at any position of the peptide sequence. Intelligent response: The incorporation of the azobenzene moiety into the side chain of low-molecular-weight peptides allows for the preparation of multistimuli-responsive supramolecular organogels. The presence and position of the azobenzene residue act as a versatile regulator to reduce the minimum gelation concentration and enhance both the thermal stability and mechanical strength of the materials (see figure). Copyright
View MoreSHIJIAZHUANG HENRYTE CHEMICALS CO,.LTD(expird)
Contact:+86-311-85208698 311-80837698
Address:NO.166, yuhua west road, SHIJIAZHUANG, China
Changzhou Sunlight Pharmaceutical Co., Ltd.
Contact:+86-519-83131668;83139028;83138042;83137041
Address:JiuliStreet, Benniu Town Changzhou City, Jiangsu Province
BAODING SINO-CHEM INDUSTRY CO.,LTD
Contact:0312-5956088
Address:NO.8 FUXING ROAD,CHINA
Contact:+86-531-58668191 58668193 58668196 58661173
Address:No 55,Beixiaoxinzhuang West Street,Jinan City, Shandong Province
Shanghai Egoal Chemical Co.,Ltd
Contact:+86-21-50333091
Address:Yangming Garden Square 3,YangGao North Road 1188, Pudong New District, Shanghai
Doi:10.1002/ejoc.200601019
(2007)Doi:10.1039/jr9610005137
(1961)Doi:10.1016/j.tetlet.2011.08.121
(2011)Doi:10.1021/jp021216l
(2002)Doi:10.1021/jo01209a003
(1940)Doi:10.1016/S0008-6215(02)00084-8
(2002)