Die Kristall- und Molekülstrukturen von Chlorotrispyridinium-bis-(tetrachloroaluminat(III)) und einer weiteren Modifikation von Pyridiniumchlorid

Crystal- and Molecular Structures of Chlorotrispyridinium-bis-(tetrachloroaluminate(III)) and a New Modification of Pyridinium Chloride The compounds PyHCl and ((PyH)₃Cl)(AlCl₄)₂ are formed by hydrolysis during the synthesis of adducts in the system AlCl₃/pyridine. The second room temperature modification of PyHCl crystallizes in the space group P2₁/c with the lattice constants a = 847.9(3), b = 1770.2(3), c = 801.9(3) pm, β = 95.23(3)°, Z = 8. The atomic parameters were refined from 4471 measured intensities to R(F) = 6,9%. The N? Cl distances are 306.8(7) and 311.0(8) pm. The unit cell of ((PyH)₃Cl)(AlCl₄)₂ is orthorhombic (space group Pbca) and has the lattice constants a = 1306.3(4), b = 1589.4(4), c = 2708.6(7) pm, Z = 8. The crystal structure was refined from 7226 measured intensities to R(F) = 6.7%. The cation shows three pyridinium ions to have NH…?Cl hydrogen bonds to a central positioned chloride ion with N? Cl distances of 301.4(7), 305(1) and 306(1) pm.