Cation complexation of quinocrown ethers in electrospray ionization mass spectrometry. A comparison with benzocrown ethers
作者:Akihiko Tsuda、Hiroshi Moriwaki、Takumi Oshima
DOI:10.1039/a808752k
日期:——
The alkali metal complexation of 15- to 18-membered ring quinocrown ethers Q15–18, 18- and 24-membered diquinocrown ethers DQ18,24, and 18-membered quinobenzocrown ether QB18 is compared with that of the corresponding benzocrown ethers B15–18 and dibenzo crown ethers DB18,24 in electrospray ionization mass spectrometry (ESI-MS). The quinocrown ethers exhibit lower cation affinity than the benzocrown ethers, although the two crown series essentially show the same ion selectivity except 18-membered DQ18 which preferentially binds Na+. The reduced binding ability of the quinocrowns is interpreted in terms of the deformation of the crown rings by the steric repulsion with the quinone carbonyls as well as the electron withdrawing ability of the fused quinone.
DIETL, F.;GIERER, G.;MERZ, A., SYNTHESIS, BRD, 1985, N 6-7, 626-631
作者:DIETL, F.、GIERER, G.、MERZ, A.
DOI:——
日期:——
Chinone von Benzo- und Dibenzokronenethern
作者:F. Dietl、G. Gierer、A. Merz
DOI:10.1055/s-1985-34140
日期:——
Quinones of Benzo- and Dibenzo-Crown Ethers: The preparation of the 1,4-quinones of benzo[15]crown-5 (1), benzo [18]crown-6 (2) and dibenzo[18]crown-6 (3) and their quinols is described. The quinones are obtained by Fremy salt oxidation of the corresponding 3-hydroxybenzo-crown ethers which are readily accessible by a double protective group synthesis from 1,2,3-trihydroxybenzene. The synthetic pathway also provides a general high yield preparation of 2,3-dialkoxyl-1,4-benzoquinones. The new crown ethers are characterised b y 1H- and 13C-N. M. R. as well as U. V. spectroscopy. Non-aqueous redox potentials are determined by cyclic voltammetry. Crystalline complexes of 1 and 2 with various ammonium, alkali, and alkaline earth cations are also described.