Organization of Mn-Clusters in <i>pcu</i> and <i>bcu</i> Networks: Synthesis, Structure, and Properties

Abstract

Two new anionic inorganic–organic hybrid compounds [H3O][Mn3(μ3-OH)(C14H8O6S)3(H2O)](DMF)5, I, and [H3O]2[Mn7(μ3-OH)4(C14H8O6S)6(H2O)4](H2O)2(DMF)8, II, have been prepared by employing mild solvothermal methods. Both the compounds have three-dimensionally extended structures formed by Mn6 and Mn7 clusters, respectively. The connectivity between Mn6 and Mn7 clusters and 4,4′-sulfonyldibenzoic acid anions (SDBA2–) results in a six connected pcu network in I and an eight connected bcu network in II. The presence of hydronium ion (H3O+) along with the solvent molecules in the channels of both the compounds suggested proton conduction in the solids. Proton conductivity studies gave values of ∼3 × 10–4 Ω–1 cm–1 98% relative humidity in both the compounds. The high activation energies indicate a vehicle mechanism in the compounds I and II. Magnetic studies indicate antiferromagnetic behavior in both the compounds.