Metal–organic frameworks of manganese(ii) 4,4′-biphenyldicarboxylates: crystal structures, hydrogen adsorption, and magnetism properties

Abstract

Reactions of 4,4′-biphenyldicarboxylic acid (H₂bpdc) with manganese(II) nitrate under solvothermal conditions yield two types of new metal–organic frameworks, [Mn₄(bpdc)₄(DMF)₃](DMF) (1) (DMF = N,N′-dimethylformamide) and Mn₃(bpdc)₃(DMA)₄ (2) (DMA = N,N′-dimethylacetamide). Structural analysis shows different solvents lead to distinct phases of manganese(II) 4,4′-biphenyldicarboxylate although the same starting materials are employed. Complex 1 features a microporous noninterpenetrated structure with nano-sized channels and a rare cem topological net, while 2 is non-porous with an α-polonium topology. Microporous 1 exhibits significant hydrogen adsorptive capability. Magnetic behaviors of the both complexes suggest the presence of antiferromagnetic interactions.