Two 3D Mn-based coordination polymers: synthesis, structure and magnetocaloric effect

Two three-dimensional (3D) coordination polymers, namely MnII6(CH3COO)(2)(HCOO)(2)(IN)(8)(C4H8O)(2)(H2O) and MnIII6MnII12(mu(3)-O)(6)(CH3COO)(12)(IN)(18)(H2O)(7.5)(abbreviated asMnII6andMnII12MnIII6respectively; HIN = isonicotinic acid), were synthesized by the reaction of Mn(CH3COO)(2)center dot 4H(2)O and isonicotinic acid under solvothermal conditions. Magnetic studies revealed that antiferromagnetic interactions may be present in compoundsMnII6andMnII12MnIII6. Moreover, the values of -Delta S-m(26.27 (MnII6) and 37.69 (MnII12MnIII6) J kg(-1)K(-1)at Delta H= 7 T) are relatively larger than those of the reported Mn-based coordination polymers. This work provides a great scope in the magnetocaloric effect (MCE) of pure 3d-type systems.