A new di-block copolymer composed of a regioregular block of poly[3-[2-(2methoxyethoxy)ethoxy]methylthiophene], bearing as side-chain a hydrophilic substituent, and a regioregular block of poly[3-(1-octyloxy)thiophene], has been prepared and characterized. The properties are compared with those of a related copolymer composed of poly(3hexylthiophene) and poly(3-alkoxythiophene) blocks. The solvatochromic properties of these materials in solution have been investigated by absorption and emission spectroscopy upon gradual addition of a poor solvent, and compared with those of the parent regioregular homopolymers. The experimental results are interpreted in terms of electronic interactions between the blocks. It is found that the different hydrophilicity of the side-chain plays a crucial role for the electronic communication between blocks in poly(3-alkylthiophene)-bpoly(3-alkoxythiophene) copolymers.
Two novel optically active terthiophene and bithiophene monomers bearing at the C-β position of thiophene ring an enantiomerically pure chiral alkyl group, namely 3,3″-di[2-((S)-(+)-2-methylbutoxy)ethyl]-2,2':5',2″-terthiophene and 3,3'-di[2-((S)-(+)-2-methylbutoxy)ethyl]-2:2'-bithiophene, have been synthesized and characterized. Being symmetrically substituted, their polymerization adopting simple and economic method, such as the chemical oxidation with iron (III) trichloride, allowed to obtain regioregular macromolecules. The synthesized polymers have been investigated by CD in solution as well as in the microaggregated state upon gradual addition of a poor solvent. The results display different CD behaviors related to their chemical structure.
The synthesis and characterization of an optically active quinquethiophene monomer 3,3””-didodecyl-4’,3”’-di[(S)-(+)-2-methylbutyl]- 2,2’:5’,2”:5”,2”’:5”’,2””-quinquethiophene [(S)-(+)-DDDMBQT], bearing at the C-β positions of thiophene rings both linear C12 alkyl chain and chiral, enantiomerically pure, alkyl group is described. The polymerization of [(S)-(+)-DDDMBQT] by oxidative mechanism has been optimized in terms of yield of soluble polymer with high molecular weight.The obtained polymeric derivative displays enhanced conjugation extension with respect to similar poly(3-alkylthiophene)s reported in the literature and optical activity in the spectral region related to the chromophore absorptions when in the microaggregate state, indicative of the presence of supramolecular chiral conformations.
Abstract:The spectroscopic behavior of thin films of regioregular poly(alkylthiophene)s bearing an optically active alkyl group has been investigated in the solid state under different sample preparation procedures. The experimental results are interpreted in terms of influence of the side-chain substituents on the extent of planarity of the polymeric chains and the formation of optically active chiral aggregates.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.