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

Two three-dimensional (3D) coordination polymers, namely Mn(II)(6)(CH(3)COO)(2)(HCOO)(2)(IN)(8)(C(4)H(8)O)(2)(H(2)O) and Mn(III)(6)Mn(II)(12)(μ(3)-O)(6)(CH(3)COO)(12)(IN)(18)(H(2)O)(7.5) (abbreviated as Mn(II)(6) and Mn(II)(12)Mn(III)(6) respectively; HIN = isonicotinic acid), were synthesized by the reaction of Mn(CH(3)COO)(2)·4H(2)O and isonicotinic acid under solvothermal conditions. Magnetic studies revealed that antiferromagnetic interactions may be present in compounds Mn(II)(6) and Mn(II)(12)Mn(III)(6). Moreover, the values of −ΔS(m) (26.27 (Mn(II)(6)) and 37.69 (Mn(II)(12)Mn(III)(6)) J kg(−1) K(−1) at ΔH = 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.