American Chemical Society
jo101882r_si_001.cif (29.76 kB)

N-Tosylpyrrolidine Calix[4]pyrrole: Synthesis and Ion Binding Studies

Download (29.76 kB)
posted on 2011-02-18, 00:00 authored by Sung Kuk Kim, Dustin E. Gross, Dong-Gyu Cho, Vincent M. Lynch, Jonathan L. Sessler
The synthesis and preliminary solution phase ion binding properties of the N-tosylpyrrolidine calix[4]pyrrole 2 are reported. This β-octaalkyl-substituted calix[4]pyrrole, the first to be prepared via a direct condensation reaction, was obtained by reacting the 3,4-alkyl-functionalized pyrrole 8 with acetone in the presence of an acid catalyst. On the basis of 1H NMR spectroscopic analyses and isothermal titration calorimetry, it was concluded that, compared with the parent, β-unsubstituted calix[4]pyrrole (1), compound 2 possesses significantly enhanced binding ability for halide anions in chloroform. Furthermore, 2 proved capable of solubilizing in chloroform solution the otherwise insoluble salts, CsF and CsCl. These effects are ascribed to the interactions between the four tosyl groups present in 2 and the counter cations of the halide anion salts.