Complexes between pilocarpine and cobalt(II), nickel(II), copper(II), and zinc(II) ions.

The properties of pilocarpine as a ligand toward the halides of cobalt(II), nickel(II), copper(II), and zinc(II) were investigated. Pilocarpine behaved as a monodentate ligand, giving rise to compounds with the general formula methyl(pilocarpine)2X2. The coordinating geometry at the metal ion was pseudotetrahedral in every case. PMR studies showed that the pyridine-type nitrogen of the imidazole ring of pilocarpine was the donor atom of the ligand.