The asymmetric unit of the title compound, C(25)H(22)P(+)·ClO(4) (-), contains two independent cations and two independent anions. The closest inter-molecular contact is a weak inter-molecular C-H⋯π(arene) inter-action.

p-tert-Butylcalix[8]arene-octaacetic acid octaethyl ester and calix[8]arene-octaacetic acid octaethyl ester well recognized 2-phenylethylamine and phenylalanine methyl ester compared with the corresponding calix[6]arene derivatives. Moreover, the calix[8]arene derivatives, especially one having tert-butyl groups, gave better selectivity against biologically active amines having a complicated st...

Cationic titanium(IV) complexes with ansa-(eta(5)-cyclopentadienyl,eta(6)-arene) ligands were synthesized and characterized by X-ray crystallography. The strength of the metal-arene interaction in these systems was studied by variable-temperature NMR spectroscopy. Complexes with a C(1) bridge between the cyclopentadienyl and arene moieties feature hemilabile coordination behavior of the ligand ...

In order to understand the still-poorly understood interplay between calix[4]arene conformations and cation and anion recognition in multicomponent systems, the ion pair receptors 1 and 2 were synthesized. In solution and in the solid state, the calix[4]arene subunit of receptor 1 adopts a cone conformation, while that of 2 interconverts between the cone and the partial cone conformation. These...