Structural and spectroscopic characterization of epiisopiloturine-metal complexes, and anthelmintic activity vs . S. mansoni

Herein, EPI was complexed with copper(II) or zinc(II) salts and the isolated species, [Cu(epi) 4 ](ClO 4 ) 2 ( 1 ) and [Zn(epi) 2 Cl 2 ] ( 2 ), were structurally and spectroscopically characterized.

By using X-ray diffraction, the crystal structures of both metal complexes were determined, indicating a square pyramidal geometry for copper for 1 and a tetrahedral environment around zinc for 2 . EPR spectra of 1 show a typical tetragonal environment around the central metal ion with some tetrahedral distortion, both in the solid state and in frozen acetonitrile solution, in accordance with crystallographic data. For 2 , NMR spectra have bands consistent with a tetrahedral species in solid state or in DMSO-d 6 solution.