Self-assembly of reduced molybdophosphate-based supramolecular architectures and the study of their magnetic properties

Reduced molybdophosphate-based supramolecular compounds, such as (4,4'-H(2)bipy)[Co(H2O)(2)](2)[Co(H2PO4)(2)(HPO4)(4)(PO4)(2)(MoO2)(12)(OH)(6)] center dot A 17H(2)O (1), [Co(2,2'-bipy)(2)(H2O)](4)[Co(H2O)(2)][Co(HPO4)(6)(PO4)(2)(MoO2)(12)(OH)(6)] center dot A 2H(2)O (2), and [Co(2,2'-bipy)(2)(H2O)](4)[Co(H2PO4)(H2O)(2)](2)[Co(HPO4)(6)(PO4)(2)(MoO2)(12)(OH)(6)] center dot A 8H(2)O (3) (4,4'-bipy=4,4'-bipyridine, 2,2'-bipy=2,2'-bipyridine), have been synthesized under hydrothermal conditions and characterized. Compound 1 exhibits a three-dimensional supramolecular twofold interpenetrating architecture built up of one-dimensional [P4Mo6]-based infinite covalent chains and free 4,4'-bipy molecules. Compound 2 also shows a three-dimensional supramolecular network constructed from one-dimensional covalent [P4Mo6]-based chains. Unlike compounds 1 and 2, compound 3 exhibits an interesting three-dimensional 'honeycomb-like' supramolecular network constructed by the stacking of [Co(2,2'-bipy)(2)(H2O)] units with one-dimensional channels, in which the [P4Mo6]-based polyoxometalate chains are located. The magnetic properties of compounds 2 and 3 are reported.