Nanostructured rhenium oxides, which belong to the technically important group 7 transition metal oxides, have been inaccessible until now due to the lack of appropriate precursors and reaction templates. Using methyltrioxorhenium as the organometallic rhenium precursor and long-chain alkylamines as supramolecular templates, these authors have synthesized nanostructured rhenium dioxide for the first time. The products are nanocomposites that are composed of rhenium dioxide and the organic structure-directing agent used in the preparation.