Metal inorganic frameworks: Dynamic flexible architecture with extended pore order built from [Se₃]^2- linkers and [Re ₆Se₆Br₈]^2- clusters

A mesostructured chalcogenide built from Chevrel-type clusters [(Re ₆Se₆Br₂)Br₆^T] ^2- linked by ditopic [Se₃]^2- anions and synthesized in the presence of a cationic surfactant template is reported. This new mesophase, h-C₁₈PyReSeBr, exhibits remarkably well ordered hexagonal symmetry from which a reasonable structural model can be deduced on the basis of powder X-ray diffraction as well as pair distribution function (PDF) analysis. Small-angle X-ray scattering (SAXS) analysis shows that h-C ₁₈PyReSeBr possesses an enormous interfacial area of 477 m ²/g between the inorganic framework and the guest surfactant cations, which is comparable to that of mesoporous silicas when heavy metals contained in the framework are taken into consideration. The framework of h-C ₁₈PyReSeBr exhibits great flexibility and responds dynamically to the extraframework cations via an ion-exchange process.