SINGLE CRYSTAL XRD STUDY OF 4,4'-DIPYRIDYL-p-ETHOXYBENZOIC ACID AND N,N'-DIPYRIDYLPIPERAZINE -p-ETHOXYBENZOIC ACID CO-CRYSTALS: DIRECT EVIDENCE OF H-BOND INTERACTION IN THE CORRESPONDING LIQUID-CRYSTALLINE MESOGENIC PHASES

摘要

Supramolecular H-bonded complexes formed between p-ethoxybenzoic acid and 4,4'-dipyridyl or N,N'-dipyridylpiperazine were obtained as nematic liquid-crystalline phases. The corre-sponding crystals suitable for single crystal X-ray analysis were isolated and investigated. The stoichiomtery of complex 1 is (4,4'-dipyridyl)·2(p-ethoxybenzoic acid) and that of complex 2 is (N,N'-dipyridylpiperazine)·2(p-ethoxybenzoic acid). The molecular packing observed in the crystal structures investigated indicates that the mesogenic phases of the complexes are in-duced by H-bond interactions.