Synthesis, structure and magnetic properties of a tetranuclear Mn(II) complex with carbohydrazone based ligand

Abstract

A new tetranuclear complex of Mn(II), [Mn4(L)2(CH3OH)2(μ-N3)4(N3)2]∙2(CH3OH) (1), was synthesized and characterized by spectroscopic methods, single-crystal X-ray diffraction analysis and TGA analysis where HL is bis-[(E)-N′-(phenyl(pyridin-2-yl)methylene)]carbohydrazide. Single crystal X-ray analysis reveals that 1 has a Mn4 core in which Mn(II) ions are connected by azide and enolate oxygen atoms. IR spectroscopy and X-ray analysis indicate that the carbohydrazone is coordinated to the metal cores as a mononegative ligand in the enol form. The magnetic behavior of 1 was investigated between 2 and 295K and indicated that the magnetic coupling mediated via azide bridge is ferromagnetic whereas the enolate oxygen mediates antiferromagnetic coupling that leads to overall antiferromagnetic behavior.