2150-02-9Relevant articles and documents
A highly selective fluorescent sensor for mercury ion (II) based on azathia-crown ether possessing a dansyl moiety
Dai, Huajun,Liu, Fei,Gao, Qianqian,Fu, Tianhua,Kou, Xingming
, p. 523 - 530 (2011)
An intramolecular charge transfer (ICT) fluorescent sensor 1 using a dansyl moiety as the fluorophore and an azathia-crown ether as the receptor was designed, synthesized and characterized. The ions-selective signaling behaviors of the sensor 1 were investigated in CH3CN-H2O (1:1, v/v) by fluorescence spectroscopy. It exhibited remarkable fluorescence quenching upon addition of Hg2+, which was attributed to the 1:1 complex formation between 1 and Hg2+, while other selected metal ions induced basically no spectral changes. The sensor 1 showed a rapid and linear response towards Hg2+ in the concentration range from 5.0 × 10 -7 to 1.0 × 10-5 mol L-1 with the detection limit of 1.0 × 10-7 mol L-1. Furthermore, the whole process could be carried out in a wide pH range of 2.0-8.0 and was not disturbed by other metal ions. Thus, the sensor 1 was used for practical determination of Hg2+ in different water samples with satisfactory results. Copyright
Application of HPLC for the screening of separation of new macrocyclic systems
Stefaniak, Monika,Romański, Jaros?aw
, p. 245 - 248 (2017/01/22)
The efficient synthesis of new macrocyclic systems via nucleophilic ring opening reaction of epoxides by thiols was described. Initially new macrocyclic compounds were obtained as a mixture of diastereomers. Preparative thin layer chromatography was applied to separate meso and pairs of enantiomer. The identification of products using a chiral HPLC column and mass spectroscopy was utilized.
Single-step synthesis of internally functionalizable hyperbranched polyethers
Roy, Raj Kumar,Ramakrishnan
, p. 4125 - 4135 (2013/09/23)
Radical catalyzed thiol-ene reaction has become a useful alternative to the Hüisgen-type azide-yne click reaction as it helps expand the variability in reaction conditions as well as the range of clickable entities. In this study, the direct generation of a hyperbranched polyether (HBPE) having decyl units at the periphery and a pendant allyl group on every repeat unit of the polymer backbone is described; the allyl groups serve as a reactive handle for postpolymerization modifications and permits the generation of a variety of internally functionalized HBPEs. In this design, the AB2 monomer carries two decylbenzyl ether units (B-functionality), an aliphatic -OH (A-functionality) and a pendant allyl group within the spacer segment; polymerization of the monomer readily occurs at 150 °C via melt transetherification process by continuous removal of 1-decanol under reduced pressure. The resulting HBPE has a hydrophobic periphery due to the presence of numerous decyl chains, while the allyl groups that remain unaffected during the melt polymerization provides an opportunity to install a variety of functional groups within the interior; thiol-ene click reaction with two different thiols, namely 3-mercaptopropionic acid and mercaptosuccinic acid, generated interesting amphiphilic structures. Preliminary field emission scanning electron microscope (FESEM) and Atomic Force Microscopy (AFM) imaging studies reveal the formation of fairly uniform spherical aggregates in water with sizes ranging from 200 to 400 nm; this suggests that these amphiphilic HBPs is able to reconfigure to generate jellyfish-like conformations that subsequently aggregate in an alkaline medium. The internal allyl functional groups were also used to generate intramolecularly core-crosslinked HBPEs, by the use of dithiol crosslinkers; gel permeation chromatography traces provided clear evidence for reduction in the size after crosslinking. In summary, we have developed a simple route to prepare core-clickable HBPEs and have demonstrated the quantitative reaction of the allyl groups present within the interior of the polymers; such HB polymeric systems that carry numerous functional groups within the core could have interesting applications in analyte sequestration and possibly sensing, especially from organic media.
