Crystal and molecular structure of bis(protonated thiamine) tetrachlorodioxouranium(VI)

The crystal and molecular structure of bis(protonated thiamine) tetrachlorodioxouranium(VI), [C₁₂H₁₈ClN₄OS]₂ UO₂Cl₄, has been determined from three-dimensional X-ray diffractometer data. The crystals are monoclinic:P2₁/n,a = 11.199,b = 6.968,c = 23.675 Å, = 97.50°,Z = 2.The structure was determined by Fourier methods and refined by least squares toR = 0.062, using 1675 observed reflections.The structure contains octahedral [UO₂ Cl₄]^2–ions with average U-Cl and U-O distances of 2.67(1) and 1.78(1) Å, respectively.The organic portion of the molecule resembles that of previously reported thiamine structures. The failure to find the hydrogen atoms no doubt prevented our determining either which nitrogen atom is protonated or, with certainty, the hydrogen-bonding distribution.