Structural Characterization of Gigantic Pores in Metal-Organic Frameworks

Metal–Organic Frameworks (MOFs) are an emerging class of porous crystalline materials that exhibit exceptional tunability and potential for a wide range of applications, from gas storage and separation to catalysis and drug delivery. Recent advances in reticular chemistry have enabled the rational design and synthesis of MOFs with increasingly large pore sizes and unit cells.

We have successfully synthesized a series of highly porous MOFs with unit cell dimensions that far exceed those of conventional frameworks (>220 Å) which exhibit record-breaking gas captures. These materials show low-angle diffraction peaks, which fall outside the detection range of standard laboratory PXRD equipment. Furthermore, the large internal voids result in intrinsically weak diffraction intensities, making in-house characterization particularly challenging. To accurately resolve their structural features and confirm their long-range order, we require synchrotron-based small-angle X-ray scattering (SAXS). Access to synchrotron radiation will be essential to determine the crystallinity, periodicity, and pore architecture of these ultraporous frameworks, which cannot be properly characterized using conventional sources