- 作者: 鄭聖凡、洪煥毅、劉高家秀
- 作者服務機構: Department of Chemistry, National Taiwan Normal University, Taipei 11718, Taiwan , R.O.C.
- 中文摘要: The selectivity of eight lariat crown ethers in the sym-dibenzo-16-crown-5 series toward alkali metal ions was studied with electrospray ionization mass spectrometry under different conditions. With the exception of 2g, which is equally selective toward Na+ and Li+, all other lariat crown ethers show the best selectivity toward Li+ in methanol. Factors that influence the selectivity include the water content, counterions, nature of the side arms, and the externally added cations. Iodide gives the best Na+ selectivity with RI > RBr > RCl. Increased water content profoundly increases the Na+ selectivity when the side arm is hydrophilic and the steric hindrance is small. Externally added cations (Cs+ and/or Rb+) enhance the Na+ selectivity by exchanging the smaller Li+ from the cavity.
- 英文摘要: --
- 中文關鍵字: ESI-MS; Lariat crown ether; Selectivity.
- 英文關鍵字: --