Introducing a pyrazole/imidazole based hybrid cyclophane: a hydrogen bond sensor and binucleating ligand precursor.

A novel cyclophane consisting of methylene-bridged imidazolium- and pyrazole-moieties (calix[4]imidazolium[2]pyrazole) and two of its applications are presented. First, supramolecular recognition of an acetonitrile molecule by hydrogen bonding in the solid state is examined. Second, the capability to act as a ligand precursor is shown by the synthesis and characterisation of the respective dinuclear NHC-nickel(II) complex.