Metal complexes of a new ligand derived from 2,3-quinoxalinedithiol and 2,6-bis(bromomethyl)pyridine

The synthesis of a new ligand containing quinoxaline and pyridine subunits is described. The reaction of 2,3-quinoxalinedithiol with 2,6-bis(bromomethyl)pyridine leads to the isolation of bis(2-thio-3-mereaptoquinoxalino)-2,6-dimethylpyridine (L), which is a macrocyclic ligand precursor. The reaction of transition metal ions with L gives [M(L)X]X complexes (where M = Mn(II), Co(II), Cu(II), Ag(I), Zn(II), or Cd(II), and X = CI or Br). The compounds were characterized by physical and spectroscopic measurements which indicated that the ligand is probably acting as a pentadentate NS4 chelating agent.