Recommanded Product: 1,4,7,10,13-PentaoxacyclopentadecaneIn 2020 ,《Specific Host-Guest Interactions in the Crown Ether Complexes with K+ and NH4+ Revealed from the Vibrational Relaxation Dynamics of the Counteranion》 was published in Journal of Physical Chemistry B. The article was written by Zhou, Dexia; Hao, Hongxing; Ma, Yinhua; Zhong, Hongmei; Dai, Ya’nan; Cai, Kaicong; Mukherjee, Somnath; Liu, Jing; Bian, Hongtao. The article contains the following contents:
The specific host-guest interactions in the corresponding complexes of K+ and NH4+ with typical crown ethers were investigated by using FTIR and ultrafast IR spectroscopies. The counteranions, i.e., SCN-, were employed as a local vibrational probe to report the structural dynamics of the complexation. It was found that the vibrational relaxation dynamics of the SCN- was strongly affected by the cations confined in the cavities of the crown ethers. The time constant of the vibrational population decay of SCN- in the complex of NH4+ with the 18-crown-6 was determined to be 6 ± 2 ps, which is ~30 times faster than that in the complex of K+ with the crown ethers. Control experiments showed that the vibrational population decay of SCN- depended on the size of the cavities of the crown ethers. A theor. calculation further indicated that the nitrogen atom of SCN- showed preferential coordination to the K+ ions hosted by the crown ethers, while the NH4+ can form hydrogen bonds with the oxygen atoms in the studied crown ethers. The geometric constraints formed in the complex of crown ethers can cause a specific interaction between the NH4+ and SCN-, which can facilitate the intermol. vibrational energy redistribution of the SCN-. The experimental process involved the reaction of 1,4,7,10,13-Pentaoxacyclopentadecane(cas: 33100-27-5Recommanded Product: 1,4,7,10,13-Pentaoxacyclopentadecane)
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: 1,4,7,10,13-Pentaoxacyclopentadecane
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem