Syntheses and structure characterization of ten acid-base hybrid crystals based on N-containing aromatic bronsted bases and mineral acids

Cocrystallization of the aromatic bronsted bases with a series of mineral acids gave a total of ten hybrid salts with the compositions: (2-methylquinoline)2: (hydrochloride acid): 3H(2)O [(HL1)(+)center dot(L1)..(Cl-)center dot(H2O)(3)] (1), (6-bromobenzo[d]thiazol-2-amine): (hydrochloride acid) [(HL2)(+)center dot(Cl-)] (2), (6-bromobenzo[d]thiazol-2amine): (nitric acid) [(HL2)(+)center dot(NO3-)] (3), (6-bromobenzo[d]thiazol-2-amine): (sulfuric acid) [(HL2)(+)center dot (HSO4)(-)] (4), (6-bromobenzo[d]thiazol-2-amine): (phosphoric acid) [(HL2)(+)center dot(H2PO4)(-)] (5), (5,7-dimethy11,8-naphthyridine-2-amine): (hydrochloride acid): 3H(2)O[(HL3)(+)center dot(Cl-) (H2O)(3)] (6), (5,7-dimethyl-1,8naphthyridine-2-amine): (hydrobromic acid): CH3OH [(HL3)(+)center dot(Br)(-)center dot CH3OH] (7), (5,7-dimethyl-1,8naphthyridine-2-amine): (sulfuric acid): H2O [(HL3)(+)center dot(HSO4)(-)center dot H2O] (8), (2-aminophenol): (phosphoric acid) [(HLA)(+)center dot(H2PO4)(-)] (9), and (2-amino-4-chlorophenol): (phosphoric acid) [(HL5)(+)center dot(H2PO4)(-)] (10). The ten salts have been characterized by X-ray diffraction analysis, IR, and elemental analysis, and the melting points of all the salts were also reported. And their structural and supramolecular aspects are fully analyzed. The result reveals that among the ten investigated crystals the ring N of the heterocycle or the NH2 in the aminophenol are protonated when the acids are deprotonated, and the crystal packing is interpreted in terms of the strong charge-assisted classical hydrogen bonds between the NH+/NH3+ and deprotonated acidic groups. Further analysis of the crystal packing of the salts indicated that a different family of additional CH-O, CH-Cl, CH3-N, CH3-O, CH-Br, CH3-Br, Br-CI, Cl-S, O-S, O-O, Br-S, H-H, and pi-pi associations contribute to the stabilization and expansion of the total high-dimensional frameworks. For the coexistence of the various weak nonbonding interactions these structures adopted homo or hetero supramolecular synthons or both. Some classical supramolecular synthons, such as R-2(2)(8), R-4(2)(8), R-4(3)(10) and R-4(4)(12), usually observed in the organic solids, were again shown to be involved in constructing most of these H-bonding networks. (C) 2017 Elsevier B.V. All rights reserved.