Crystal structure of the 1:1 co-crystal 4-(di­methylamino)­pyridin-1-ium 8-hy­droxy­quinoline-5-sulfonate–N,N-di­methyl­pyridin-4-amine

Abstract

The asymmetric unit of the title compound consists of two independent ion pairs of 4-(di­methyl­amino)­pyridin-1-ium quinolin-8-ol-5-sulfonate (HDMAP⁺·HqSA⁻) and neutral N,N-di­methyl­pyridin-4-amine (DMAP), forming a 1:1:1 cation:anion:neutral mol­ecule co-crystal. The compound has a layered structure, including cation layers of HDMAP⁺ with DMAP and anion layers of HqSA⁻ in the crystal. The cation and anion layers are linked by inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions.

The asymmetric unit of the title compound is composed of two independent ion pairs of 4-(di­methyl­amino)­pyridin-1-ium 8-hy­droxy­quinoline-5-sulfonate (HDMAP⁺·HqSA⁻, C₇H₁₁N₂⁺·C₉H₆NO₄S⁻) and neutral N,N-di­methyl­pyridin-4-amine mol­ecules (DMAP, C₇H₁₀N₂), co-crystallized as a 1:1:1 HDMAP⁺:HqSA⁻:DMAP adduct in the monoclinic system, space group Pc. The compound has a layered structure, including cation layers of HDMAP⁺ with DMAP and anion layers of HqSA⁻ in the crystal. In the cation layer, there are inter­molecular N—H⋯N hydrogen bonds between the protonated HDMAP⁺ mol­ecule and the neutral DMAP mol­ecule. In the anion layer, each HqSA⁻ is surrounded by other six HqSA⁻, where the planar network structure is formed by inter­molecular O—H⋯O and C—H⋯O hydrogen bonds. The cation and anion layers are linked by inter­molecular C—H⋯O hydrogen bonds and C—H⋯π inter­actions.