Design of zigzag-like supramolecular 1D assemblies of polyfluorinated meta-arylenediamines and 18-crown-6

According to the X-ray crystal data, 1D assemblies formed by alternate arylenediamine and crown ether molecules are the motif of the supramolecular architecture of crystal associates of 18-crown-6 and polyfluorinated meta-arylenediamines, i.e. 2,4,5-trifluoro-, tetrafluoro-, 2,5,6-trifluoro-4-trifluoromethyl-, 2,5-difluoro-4,6-bis(trifluoromethyl)-1,3-phenylenediamines, and hexafluoro-2,7-naphthylenediamine. Molecules in the assemblies are coordinated by means of the hydrogen bond between the oxygen atoms of the crown ether and the hydrogen atoms of the polyfluoroarene amino groups. Due to the mutual meta-location of amino groups in a rigid aromatic framework, the molecules of the each component are arranged in a zigzag line along the rod axis. The zigzag arrangement of components in the 1D assemblies and the supramolecular architecture of co-crystals persist when the aromatic framework size increases and when one or two bulky CF3 groups are incorporated into ortho-positions to the amino groups. Using differential scanning calorimetry (DSC), specific melting heats of co-crystals have been determined, which trend towards a decrease with an increase of the 1D assembly unit lengths.