Different solvates of two isomeric dicarboxylic acids with pyridine and quinoline

The 2-[7-(2-carboxy-phenyl)-1,3,6,8-tetraoxo-3,6,7,8-tetrahydro-1H-benzo[lmn][3,8]phenanthrolin-2-yl]-benzoic acid (A) forms two polymorphic solvates with pyridine. The polymorphs arise from differences in the hydrogen bond interactions. Two different solvates of A with quinoline are also prepared and structurally characterized. These quinoline solvates are formed via encapsulation of quinoline in the assemblies of quinoline with A. The quinoline molecules in these solvates are hydrogen bonded to dicarboxylic acid (A) through different types of hydrogen bonds. The solvates of 3-[7-(3-carboxy-phenyl)-1,3,6,8-tetraoxo-3,6,7,8-tetrahydro-1H-benzo[lmn][3,8]phenanthrolin-2-yl]-benzoic acid (B) with pyridine or quinoline form assemblies which encapsulate additional pyridine or quinoline molecules.