Supramolecular architecture of crown-containing styryl dyes: Part I. Crystal and molecular structures of the acetonitrile solvate monohydrate of the potassium iodide complex with benzo-15-crown-5 ether dye based on methylquinoline iodide

The structure of a single crystal of the acetonitrile solvate monohydrate of the potassium iodide complex with benzo-15-crown-5 ether dye based on methylquinoline iodide (I) is determined by X-ray diffraction. It is established that the single crystal contains positively charged molecules of benzocrown ether photodye (D), K+ cations, I− anions, and water and acetonitrile solvate molecules in the ratio 1: 0.5: 1.5: 1: 1, respectively. The K+ cation and one of the I− anions occupy special positions along the twofold axis. The K+ cation is coordinated by ten oxygen atoms of the crown ether fragments of two D molecules to form the [D2K]3+ complex. Inside the complex, two aromatic quinoline fragments are involved in a stacking interaction. The crossed mutual arrangement of the ethylene fragments and the considerable distance between them exclude the occurrence of intramolecular photochemical [2 + 2]cycloaddition reactions. In the crystal, the [D2K]3+ cationic complexes form stacks along the b axis. The adjacent complexes in a stack are related through the center of symmetry and, therefore, are arranged in a head-to-tail manner. The double bonds of the neighboring molecular cations D in a stack are strictly parallel to each other and are separated by a distance of 3.754 Å. This geometry is favorable to the intermolecular cycloaddition reaction that should result in the formation of the syn head-to-tail isomer.