Bis-type modifiers in polymerization. I. Behavior of various disulfides in bulk styrene polymerization
作者:R. M. Pierson、A. J. Costanza、A. H. Weinstein
DOI:10.1002/pol.1955.120178407
日期:1955.6
Modifiers with bis-type structures are of interest as a means for conferring reactive groups onto the highest possible fraction of polymer chain ends. Various disulfides and other bis-typecompounds—some with reactive groups attached—were compared as to their effectiveness as modifiers in low conversion bulkstyrenepolymerizations and studies made of their mechanism of cleavage. Alkyl disulfides of
Convenient microwave-assisted synthesis of lipophilic sulfenamide prodrugs of metformin
作者:Kristiina M. Huttunen、Jukka Leppänen、Krista Laine、Jouko Vepsäläinen、Jarkko Rautio
DOI:10.1016/j.ejps.2013.05.023
日期:2013.7
A convenient microwave-assisted synthesis of lipophilic sulfenamide prodrugs of antidiabetic agent, metformin, is reported in this study. These acyclic prodrugs were synthesized directly from selected disulfides with basic metformin and silver nitrate by a one-pot reaction under microwave irradiation. The prepared prodrugs had significantly increased lipophilicity, which resulted in excellent permeability
A photo-oxidative homo-coupling of thiol was promoted by BrCCl3 in THF. This catalyst- and metal-free method was used to synthesize disulfides under mild conditions. The clean reaction minimized the possibility of contamination of the product.
Treatment of 2-methylsulfinylbenzazoles with triflic anhydride in the presence of phenols yields the corresponding 4-(p-hydroxyphenyl)-2-methylsulfanylbenzazoles. This regioselective dehydrative C–H/C–H coupling arylation represents a rare example of functionalizations on the benzene rings of benzo-fused azoles.
Tuning the Electronic Properties of Poly(thienothiophene vinylene)s via Alkylsulfanyl and Alkylsulfonyl Substituents
作者:Julia A. Schneider、Afshin Dadvand、Wen Wen、Dmitrii F. Perepichka
DOI:10.1021/ma402018n
日期:2013.12.10
The use of alkylsulfanyl and alkylsulfonyl side chains are demonstrated to be a useful synthetic strategy for tuning the electronic properties of organic semiconductors, as shown in thienothiophene vinylene polymers. By changing the oxidation state of sulfanyl to sulfonyl, we lower the HOMO and LUMO energy levels of our substituted polymers, as well as enhance their fluorescence. Fine-tuning of the energy levels was achieved by combining sulfanyl and sulfonyl substituted thienothiophene monomers through random polymerization, yielding polymers with low-band gaps (1.5 eV) yet benefiting from a structurally uniform conjugated backbone. The effects of these functional side chains are presented through DFT calculations, UV-vis, fluorescence, and electrochemical measurements, as well as crystallographic analysis of a sulfanyl-substituted oligomer. The semiconducting properties of the new polymers are studied in OFET and OPV devices.