Co-crystallization of oxadiazole-bridged pyridyl-N-oxide building modules with R-aromatics (R = –OH, –NH2 and –COOH)

Abstract

The reaction of oxadiazole bridging pyridyl-N-oxides (2,5-bis(4-pyridyl-N-oxide)-1,3,4-oxadiazole (A1) and 2-(4-pyridyl)-5-(4-pyridyl-N-oxide)-1,3,4-oxadiazole (A2)) with different substituted aromatics (R-aromatics, R = –OH, –NH₂, –COOH) have been investigated. Eight new organic co-crystals of 1–8 were synthesized and characterized by elemental analysis, FTIR spectroscopy, ¹H NMR and single-crystal X-ray diffraction. The results display the distinct substituent effect on the hydrogen-bonded self-assembly systems. In addition, the luminescent properties of A1–A2 and 1–8 were investigated in the solid state.