Cationic—Anionic Pd(II) Complexes with Adamantylimidazolium Cation: Synthesis, Structural Study, and MAO-Inhibiting Activity

Abstract

New cationic-anionic palladium(II) complexes have been prepared from adamantyl-substituted imidazolium salts and effect of structure of the adamantyl-substituted salts and synthesis conditions on the structure of these complexes with \({\rm{Pd}}({\rm{DMSO}}){\rm{Hal}}_3^ - \) (1–4), \({\rm{P}}{{\rm{d}}_2}{\rm{Br}}_6^{2 - }\) (5, 6), or \({\rm{PdCl}}_4^{2 - }\) (7) anions has been studied. A number of palladium(II) complexes active against monoamine oxidase B has been prepared, effect of composition and structure on their biological activity have been revealed. The structure of the complexes has been confirmed by X-ray diffraction analysis, a conductometric study of complex 1 has been performed. MAO-inhibiting activity of the obtained complexes has been found to be on the level of reference compounds: 17.6% of residual enzyme activity upon inhibition by complex 3 as compared with 16.9% for reference compound (selegiline). Complexes with bromine ligand show higher activity than those with chlorine ligand. The results of this study can be used in organometallic and bioinorganic chemistry.