A 3D canted antiferromagnetic porous metal-organic framework with anatase topology through assembly of an analogue of polyoxometalate.

State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, PR China.

The unique porous metal-organic framework {KCo3(C6H4O7)(C6H5O7)(H2O)2.8H2O}8 (1), which exhibits an unprecedented infinite 3D (3,6)-connected decorated anatase net, has been obtained by hydrothermal reaction. Upon dehydration, the compound retains crystallinity and exhibits a type I N2 sorption isotherm, characteristic of a microporous solid with apparent Langmuir surface area 939 m2/g and pore volume 0.31 cm3/g. Magnetic measurements for both 1 and dehydrated 1 show the spin-canted antiferromagnetic state below 5 K and a magnetic hysteresis loop at 2 K. Thus, dehydrated 1 represents the first metal-organic framework for which microporosity and a spin-canted antiferromagnetic state coexist, which demonstrates that the self-assembly of organo-polymetal clusters and metal ions can provide a potential route to magnetic porous metal-organic frameworks.

PMID: 16305195 [PubMed]