Supramolecular Organic Salts Constructed from 6-Hydroxyquinoline and Nitrobenzoic Acids

Abstract

The crystal structures of the proton-transfer salts of 6-hydroxyquinoline with 3,5-dinitrobenzoic acid (1) and 4-nitrobenzoic acid (2) have been determined at room temperature. Their comparative structural features and hydrogen-bonding patterns are described here. Compound 1 crystallizes in the monoclinic P21/c space group, while 2 in the triclinic P−1 space group. Unit cell dimensions and contents are: a = 7.6956(15), b = 26.075(5), c = 7.7233(15) A, β = 95.96(3)° for 1; a = 7.7325(15), b = 8.5939(17), c = 12.394(3) A, β = 77.63(3)° for 2. Supramolecular architectures are formed by intermolecular hydrogen bonds in the proton-transfer process. The supramolecular structures are stabilized by N–H···O, O–H···O and C–H···O hydrogen bonds between the two components. Extensive hydrogen-bonding interactions give two-dimensional network structures. In addition, π–π stacking interactions exist in the salt 1 due to the aromatic rings. The crystal structures of the proton-transfer salts of 6-hydroxyquinoline with 3,5-dinitrobenzoic acid (1) and 4-nitrobenzoic acid (2) have been determined at room temperature. The supramolecular structures are stabilized by N–H···O, O–H···O and C–H···O hydrogen bonds between the two components. In addition, π–π stacking interactions exist in the salt 1 due to the aromatic rings.