Chromogenic bis(urea) spherands: synthesis and complexation of lithium and sodium ions
作者:Eddy Chapoteau、Manjit S. Chowdhary、Bronislaw P. Czech、Anand Kumar、Wolodymyr Zazulak
DOI:10.1021/jo00036a009
日期:1992.5
Syntheses of two novel 18-membered bis(urea) spherands bearing 2,4,6-trinitroanilino and 4-(diethyl-amino)phenylazo chromophores are described. The UV-vis spectral changes in the presence and absence of Na+ and Li+ ions are reported at pH optima. Chromogenic spherand 2 exhibits selectivity for Na+ over Li+ in chloroform-water extractions. In contrast, Li+ ions are bound better than Na+ by both spherands in homogeneous aqueous media. The pK(a) values are determined for spherand 2 with Na+ and Li+ in 10% aqueous diethylene glycol monoethyl ether (DEGMEE). The extraction constants (K(ex)) for K+, Na+, and Li+ are determined for 2 in chloroform saturated with water, and the extraction selectivity order is Na+ > Li+ > K+.
BRYANT, JUDI A.;HO, SIEW PENG;KNOBLER, CAROLYN B.;CRAM, DONALD J., J. AMER. CHEM. SOC., 112,(1990) N5, C. 1-3
作者:BRYANT, JUDI A.、HO, SIEW PENG、KNOBLER, CAROLYN B.、CRAM, DONALD J.
DOI:——
日期:——
Bryant, Judi A.; Ho, Siew Peng; Knobler, Carolyn B., Journal of the American Chemical Society, 1990, vol. 112, # 15, p. 5837 - 5843
作者:Bryant, Judi A.、Ho, Siew Peng、Knobler, Carolyn B.、Cram, Donald J.