ИСТИНА

The antitumor and radiosensitizing drugs being caffeine derivatives that penetrate easily through blood brain barrier have been developed [1]. They are effective with radiation and chemotherapy treatment for cases of brain tumors. The caffeine derivatives were perspective for preparation of therapeutic agents to be used in a combined therapy for primary and metastatic brain tumors [1]. The mechanism of caffeine interaction was not clear anyhow. The precise structural data for caffeine are necessary for proper understanding of its action but are very limited. To increase the accuracy of the structural date and to simulate the interaction of caffeine with tetraoxidoanion and hydration water molecules the synthesis of new set of compounds of caffeine with three metal hexahydrate perrhenates was carried out from saturated water solutions and the single crystal thus obtained were subjected to X-ray structural study at Bruker KAPPA APEX II diffractometer. All three compounds have similar stoichiometry but different coordination types. Supramolecular interactions of caffeine molecules with each other, water molecules and oxygen atoms of tetraoxidoanions as in three different new compounds of Me(H2O)6[ReO4]2∙Caffeine (Me = Co, Cd, Mg) are analyzed in this study through comparison of their different structures with quantum chemical analyses. The difference in structures is explained by the balance of cations hydration and coordination to perrhenate.