Hydrogen bond-stabilised N-alkylammonium resorcinarene halide cavitands

A family of hydrogen bond-stabilised N-alkylammonium resorcinarene chloride and bromide cavitands were synthesised and characterised with 1H NMR and ESI mass spectrometry. The seven compounds exhibit interestingly either self-inclusion or guest complexation in the solid state evidenced by single crystal X-ray diffraction. The four dimers show self-inclusion of the upper rim propyl chains and consist of two hydrogen-bonded resorcinarene tetracations and six halide anions, while the remaining two halide anions are located in between the dimers linking them via hydrogen bonding. Small solvent molecules such as dichloromethane, methanol, n-butanol or chloroform are complexed into the resorcinarene cavity in three 1:1 or 1:2 host–guest complexes. While included, the methanol and butanol molecules are simultaneously hydrogen bonded to the halide anion enhancing the complex formation. The complementary self-inclusion results in a nearly perfect cone conformation of the resorcinarene core in the dimers, while the...