Crystal structures of an imidazo[1,5-a]pyridinium-based ligand and its (C₁₃H₁₂N₃)₂[CdI₄] hybrid salt.

ABSTRACT: The monocation product of the oxidative condensation-cyclization between two mol-ecules of pyridine-2-carbaldehyde and one mol-ecule of CH₃NH₂·HCl in methanol, 2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridinium, was isolated in the presence of metal ions as bis-[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] tetra-iodo-cadmate, (C₁₃H₁₂N₃)₂[CdI₄], (I), and the mixed chloride/nitrate salt, bis-[2-methyl-3-(pyridin-2-yl)imidazo[1,5-a]pyridin-2-ium] 1.5-chlor-ide 0.5-nitrate trihydrate, 2C₁₃H₁₂N₃ ⁺·1.5Cl^-·0.5NO₃ ^-·3H₂O, (II). Hybrid salt (I) crystallizes in the space group P2₁/n with two [L]₂[CdI₄] mol-ecules in the asymmetric unit related by pseudosymmetry. In the crystal of (I), layers of organic cations and of tetra-halometallate anions are stacked parallel to the ab plane. Anti-parallel L ⁺ cations disposed in a herring-bone pattern form ?-bonded chains through aromatic stacking. In the inorganic layer, adjacent tetra-hedral CdI₄ units have no connectivity but demonstrate close packing of iodide anions. In the crystal lattice of (II), the cations are arranged in stacks propagating along the a axis; the one-dimensional hydrogen-bonded polymer built of chloride ions and water mol-ecules runs parallel to a column of stacked cations.

SUBMITTER: Vassilyeva OY 

PROVIDER: S-EPMC6690455 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature