The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: 1,5-Dibromopentane( cas:111-24-0 ) is researched.Category: chiral-nitrogen-ligands.Shan, Naisong; Shen, Chengtian; Evans, Christopher M. published the article 《Critical Role of Ion Exchange Conditions on the Properties of Network Ionic Polymers》 about this compound( cas:111-24-0 ) in ACS Macro Letters. Keywords: ion exchange network ionic polymer. Let’s learn more about this compound (cas:111-24-0).
Ionic polymers are important in a wide range of applications and can exhibit widely different properties depending on the ionic species. In the case of single ion conducting polymers, where one charge is attached to the backbone or as a side group, ion exchange is performed to control the mobile species. While the conditions are often specified, the final ion content is not always quantified and there are no clear criteria for what concentration of salt is needed in the exchange. A series of ammonium network ionic polymers with different precise carbon spacers (C4-C7) between ionic junctions was synthesized as a model system to understand how ion exchange conditions impact the resultant polymer properties. The initial networks with free bromide anions were exchanged with 1.5, 3, or 10 equiv of lithium bis(trifluoromethane) sulfonimide (LiTFSI) salt in solution For networks with seven carbons between crosslinks, increasing the LiTFSI concentration lead to an increase in ion exchange efficiency from 83.7 to 97.6 mol %. At the highest conversion, the C7 network shows a 4°C decrease in glass transition temperature, 50°C increase in degradation temperature, 12-fold lower water uptake from air, and greater than 10-fold increase in conductivity at 90°C. These results illustrate that properties such as Tg are less sensitive to residual ion impurities, while conductivity is highly dependent on the final exchange conversion.
As far as I know, this compound(111-24-0)Category: chiral-nitrogen-ligands can be applied in many ways, which is helpful for the development of experiments. Therefore many people are doing relevant researches.
Reference:
Chiral nitrogen ligands in late transition metal-catalysed asymmetric synthesis—I. Addressing the problem of ligand lability in rhodium-catalysed hydrosilations,
Nitrogen-Containing Ligands for Asymmetric Homogeneous and Heterogeneous Catalysis