1:1 Co-crystallisation of 1,2,4,5-benzenetetracarboxylic acid (LH4) with isomeric 2,2′-dipyridyldisulfide (2-PA) and 4,4′-dipyridyldisulfide (4-PA)

Abstract

Abstract The 1 : 1 co-crystallisation experiments conducted between 1,2,4,5-benzenetetracarboxylic acid, LH4, and each of 2,2′-dipyridyldisulfide (2-PA) and 4,4′-dipyridyldisulfide (4-PA) resulted in the formation of two salts of distinct formulation, i.e. [LH4]0.5[2-PAH][LH3] (1) and [LH2][4-PAH2] (2), respectively, indicating that proton transfer had occurred during crystallisation. In 1, a framework structure constructed by hydrogen bonded (O—H … O) LH4 and LH3 -0 species defines channels in which reside 2-PAH cations that feature syn geometries and intramolecular N—H … N hydrogen bonds. By contrast, in 2, direct N—H … N links between cations and anions lead to zigzag supramolecular chains.