Picking up 30 CO2 Molecules by a Porous Metal Oxide Capsule Based on the Same Number of Receptors

摘要

After the metal oxide clusters {Mo_(72)M_(30)} (M = V~(IV), Cr~(III), Fe~(III), Mo~v), {Mo_(132)} (Keplerate-type), {Mo_(154)}, {Mo_(176)}, {Mo_(248)} (wheel type), and also the (Mo_(368)} (hedgehog type) and some tungsten analogues were discovered, they were recognized as nanomaterials that allow a variety of research options in several disciplines. The corresponding results obtained from several groups refer to unusual chemical reactions (especially the work of Aida et al.) as well as electronic and magnetic properties, but also different aspects of materials science, including catalysis. In particular, the spherical nanocapsules/Keplerates of the (pentagon)_(12)(linker)_(30) = {(Mo)Mo5}_(12){Mo2}_(30) = {Mo_(132)} type containing 20 well-defined pores have been extensively investigated because of their unique structures and the related properties. This refers in particular to the option of tuning the internal capsule functionalities (including important hydrophobic types), which reveals several interesting features especially regarding interactions of the capsules with the environment. If the capsules are transferred, for example, to solutions containing different constituents at their disposition, they exchange their interior correspondingly. One example is the extremely fast exchange of 30 lower-charged acetate ligands coordinated to the 30 {Mo~v2O4}~(2+) linkers of the capsule {(Mo~(VI))Mo~(VI)5O_(21)(H2O)6}_(12) {Mo~v2O4(CH3COO)}_(30)~(42-) la by the corresponding number of more highly charged sulfate ions present in the new environment.