《Poly(ethylene oxide) helical conformation and alkali metal cation selectivity studied using electrospray ionization mass spectrometry》 was written by Yin, Changna; Fu, Jie; Lu, Xiuyang. Recommanded Product: 33100-27-5 And the article was included in Rapid Communications in Mass Spectrometry in 2020. The article conveys some information:
The poly(ethylene oxide) (PEO)-alkali metal cation interaction is widely used in many areas. The conformation of the PEO-alkali metal cation complex has been studied extensively, but the conformational mechanism is still unclear. Simulations have been used to explain the mechanism, but there is a lack of exptl. data from long PEO chains to verify the simulation results. The relative peak abundance of PEO (iso-C10H21(OC2H4)nOH (naverage = 7,) where n denotes the number of ethylene oxide (EO) units) oligomers complexed to five alkali metal cations (Li+, Na+, K+, Rb+ and Cs+) was studied using pos. electrospray ionization mass spectrometry (ESI-MS). The ion selectivity of PEO oligomers to alkali metal cations corresponded to the peak abundance in competitive ESI-MS. PEO formed its first helix when the number of EO units reached six and the helix played an important role in the ion selectivity of PEO. For larger PEO oligomers with a helix, the ion selectivity of PEO depended on the degree of host-guest matching of the cations and the helix. The highest selectivity of PEO to K+ was due to K+ providing the best shape matching with the helical cavity. For smaller PEO oligomers without a helix, the selectivity was mainly determined by the surface charge d. of the cations. Conclusions : The formational mechanism of the PEO-alkali metal cation complex was predicted. The results gave straightforward evidence to explain the conformational mechanism of the PEO-alkali metal cation complex and provided exptl. data for further simulation studies. In the experiment, the researchers used 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Recommanded Product: 33100-27-5)
1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5) is a member of crown ether Ligands. Crown-ethers are macrocyclic polyethers capable of forming host-guest complexes, especially with inorganic and organic cations. Crown-ethers can incorporate protonated primary amine compounds by formation of ion-dipole bonds with the oxygen atoms of the chiral selector. Crown-ethers have been widely used for the separation of several pharmaceuticals both in aqueous and non-aqueous media. Recommanded Product: 33100-27-5
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem