Two Cobalt-diphosphonates Templated by Long-Chain Flexible Amines: Synthesis, Structures, Proton Conductivity, and Magnetic Properties

Two new cobalt-diphosphonates templated by protonated 1,2-bis(3-aminopropylamino)ethane (BAPEN), (C8N4H26)0.5·[Co(HEDP)]·H2O (1) and (C8N4H26)·[Co2(HEDP)2(H2O)2]·5H2O (2), were hydrothermally prepared (HEDP = CH3C(OH)(PO3)2, 1-hydroxyethylidenediphosphonate). Compounds 1 and 2 exhibit anionic 1D Co-HEDP chain and 2D Co-HEDP layer structure, respectively. The structure diversities from 1D chain to 2D layer was realized by adjusting the synthetic parameters. Their magnetism and proton conduction have been studied. Magnetic measurements indicated that the title compounds exhibit weak magnetic interactions. Compounds 1 and 2 feature a proton conductivity of 3.57 × 10–4 and 9.43 × 10–5 S cm–1 at 100% relative humidity and 65 °C, respectively.