Chiang Mai Journal of Science

 Two new complexes, Cu(II)-2-amino-6-methylpyridine and Cu(II)-(6-methyl-pyridin-2-ylamino)-acetic acid, were synthesized and characterized to find out the effect of polarity, active groups and complexation on antibacterial activity. The novel ligand, (6-methyl-pyridin-2-ylamino)-acetic acid was synthesized through the rapid and straightforward reaction of 2-amino-6-methylpyridine with chloroacetic acid in less than one minute. Complex of Cu(II) with 2-amino-6-methylpyridine was prepared from the reaction of CuCl2·2H2O and 2-amino-6-methylpyridine in a mole ratio of 1: 4 in methanol. Complex of Cu(II) with (6-methyl-pyridin-2-ylamino)-acetic acid was synthesized through the reaction of CuCl2·2H2O and (6-methyl-pyridin-2-ylamino)-acetic acid in a 1:2 mole (metal:ligand) ratio in methanol. The conductivity of all complexes showed a ratio of 1: 2 cations/anions. The proposed formula of the complexes are [Cu(2-amino-6-methylpyridine)4]Cl2·2H2O and [Cu((6-methyl-pyridin-2-ylamino)-acetic acid)2]Cl2·H2O. 2-amino-6-methylpyridine is coordinated to Cu(II) via the N-H group, while, (6-methyl-pyridin-2-ylamino)-acetic acid through the carboxylic group. Both complexes were paramagnetic and are expected to have square planar geometry. [Cu((6-methyl-pyridin-2-ylamino)-acetic acid)2]Cl2·H2O inhibited the highest antibacterial activity.