@article{ref1,
title="Cooperative Binding of Calix[4]pyrrole–Anion Complexes and Alkylammonium Cations in Halogenated Solvents",
journal="Chemistry: a European journal",
year="2008",
author="Gross, Dustin E and Schmidtchen, Franz P and Antonius, Wiebke and Gale, Philip A and Lynch, Vincent M and Sessler, Jonathan L",
volume="14",
number="26",
pages="7822-7827",
abstract="Calix[4]pyrrole–chloride interactions are affected not only by the choice of countercation in halogenated solvents, but show a specific dependence on the way in which these cations are bound within the electron rich, bowl-like calix[4]pyrrole cavity formed upon chloride anion complexation. In dichloromethane, the affinities of simple meso-octamethylcalix[4]pyrrole (1) for methyl-, ethyl-, and n-butylammonium chlorides are on the order of 105, 104, and 102 M−1, respectively, as determined from isothermal titration calorimetry (ITC) analyses. These cation-dependent anion affinity effects, while clearly evident, are less pronounced in other halogenated solvents, such as 1,2-dichloroethane. Support for the proposed cation complexation selectivity is provided by solid state X-ray crystallographic analyses.<p />",
language="",
issn="0947-6539",
doi="10.1002/chem.200800899",
url="http://dx.doi.org/10.1002/chem.200800899"
}