Synthesis, crystal structures and magnetic and electrochemiluminescence properties of three manganese(II) complexes

Three novel complexes, namely, penta-mu-acetato-bis(mu(2)-2-{[2-(6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolato)-mu-formato-tetramanganese(II), [Mn-4(C13H11ClN3O2)(2)(C2H3O2)(5.168)(CHO2)(0.832)], 1, hexa-mu(2)-acetato-bis(mu(2)-2-{[2-(6-bromopyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolato)tetramanganese(II), [Mn-4(C13H11BrN3O2)(2)(C2H3O2)(6)], 2, and catena-poly[[mu(2)-acetatoacetatoaqua(mu(2)-2-{[2-(6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxy-phenolato)dimanganese(II)]-mu(2)-acetato], [Mn-2(C13H11ClN3O2)(C2H3O2)(3)(H2O)](n), 3, have been synthesized using solvothermal methods. Complexes 1-3 were characterized by IR spectroscopy, elemental analysis and single-crystal X-ray diffraction. Complexes 1 and 2 are tetranuclear manganese clusters, while complex 3 has a one-dimensional network based on tetranuclear Mn-4(L-1)(2)(CH3COO)(6)(H2O)(2) building units (L-1 is 2-{[2-( 6-chloropyridin-2-yl)hydrazinylidene]methyl}-6-methoxyphenolate). Magnetic studies reveal that complexes 1-3 display dominant antiferromagnetic interactions between Mn-II ions through mu(2)-O bridges. In addition, 1-3 also display favourable electrochemiluminescence (ECL) properties.