Fjb. Kremer et al., IMPROVED GUANIDINIUM ION-SELECTIVITY BY NOVEL CALIX[4]ARENE AND CALIX[6]ARENE RECEPTOR MOLECULES ON CHEMFETS, Perkin transactions. 2, (4), 1994, pp. 677-681
Poly(vinyl chloride) membrane CHEMFETs incorporating a novel calix[4]a
rene derivative (1). novel calix[6]arene derivatives (3, 4, 5, 6 and 7
), phosphate derivatives of p-tert-butylcalix[4]arene (2) or p-tert-bu
tylcalix[6] arene (8) with variable amounts of hydrophobic anions [pot
assium tetrakis(4-chlorophenyl)borate (KTCTPB)] have been tested for t
heir response to guanidinium ions in the presence of the interfering i
ons Na+, K+, NH,+ and Ca2+. The best guanidinium selectivity has been
obtained for the CHEMFET based on the 1.3,5-triamide derivative of p-t
ert-butylcalix[6]arene (4), with dibutyl phthalate as solvent mediator
, and 50 mol% KTCTPB with respect to the ionophore. The selectivity co
efficients (log K-Gu.j(pot)) are the highest reported for guanidinium
ions in a potentiometric sensor. The CHEMFETs show an almost ideal Ner
nstian response in the linear range (slope 58-60 mV decade(-1)).