Synthesis, Crystal Structures and Magnetic Properties of Mixed-Valent Tetranuclear Complexes with Y-Shaped MnII2MnIII2 Core

Abstract

Tetranuclear MnII2MnIII2 complexes with 1,3-bis(5-bromo-3-metoxysalicylidenaminomethyl)-2-propanol (H3bmsap) and 1,3-bis(5-chloro-3-methoxysalicylidenaminomethyl)-2-propanol (H3cmsap), [Mn4(bmsap)2(CH3CO2)3(CH3O)] (3) and [Mn4(cmsap)2(CH3CO2)3(CH3O)] (4), were synthesized and characterized by elemental analysis, infrared and diffused reflectance spectra and variable-temperature magnetic susceptibility measurements in the 2–300 K range. The crystal structures of 3 and 4 revealed a Y-shaped tetranuclear manganese cluster formed by the two Schiff-base ligands, three kinds of acetato ligands (bidentate, syn–anti-bridging, and syn–syn-bridging), and µ-methoxido ligand. The magnetic data showed the magnetic interactions among the four manganese atoms are antiferromagnetic as a whole within the tetranuclear cluster.