Solid-state synthesis of isostructural tetrachlorometallate salts of amodiaquine: crystal structure of [CdCl4][C20H24ClN3O]

摘要

Tetrachlorometallate salts [AMDH(2+)][CoCl4](2-) 1a and [AMDH(2+)][CdCl4](2-) 2a (AMDH(2+) = amodiaquine dication) were obtained by ball milling of amodiaquine with inorganic salts CoCl2 center dot 6H(2)O and CdCl2 center dot 6H(2)O, respectively, in the absence of solvent. Solution-based synthesis of [AMDH(2+)][CoCl4](2-) 1b and [AMDH(2+)][CdCl4](2-) 2b were also carried out by reaction of amodiaquine with the corresponding metal salts under reflux in methanol for 1 h. The analytical and spectroscopic data (IR, UV-Vis and NMR spectra) obtained for the compounds prepared via the two different routes are identical. The XPRD pattern of 1a closely matched the simulated pattern obtained from its reported single-crystal data. Single crystals of 2b suitable for X-ray structural analysis were obtained. The X-ray structure of 2b revealed an ionic compound with formula unit comprising of one protonated dicationic amodiaquine molecule and a tetrachlorocadmate(II) anion. The crystals are triclinic with space group P-1 and unit dimensions a = 9.3272(8) a", b = 11.1418(9) a", c = 12.482(10) a", V = 1191.89 a"(3), and Z = 2. The amodiaquine molecule is protonated both at the quinoline and quinuclidine nitrogen atom. Antimalarial efficacy of 1a on Plasmodium berghei-infected mice were investigated, and the results revealed an enhanced activity of the compound by significantly (p < 0.05) improving the suppression of parasitemia in established infection when compared with the controls.