Reversible switching between self-assembled homomeric and hybrid capsules

Abstract

We present here the reversible, guest-controlled disproportionation of homomeric and hybrid capsules using photochemistry. The supramolecular containers are self-assembled from shallow and deep cavitand modules.

Precision Switching in a Discrete Supramolecular Assembly: Alkali Metal Ion‐Carboxylate Selectivities and the Cationic Hofmeister Effect

“…Whilst self‐assembly of discrete supramolecular architectures has reached some extraordinary heights in terms of sheer size of assembly product, there are still many open questions regarding how best to develop assemblies that respond to their environment and reversibly switch between assembly states. Along these lines of thought, Rebek has shown that both photochemical switching of an azobenzene guest, or the addition of a second type of assembly subunit, can induce assembly switching in a supramolecular host . Similarly, Nitschke and Schalley have reported how mixing two homoleptic Zn 4 L 6 tetrahedra forms a dynamic combinatorial library that can be controlled by the choice of added guest .…”

Efficient synthesis of benzo[c]cinnolines and azoarenes via dual C–N coupling of phthalhydrazide and trivalent halogen reagents

“…Et), was synthesized with low efficiency via NvN coupling. 18 In contrast, 6kd was obtained in a high yield of 95% through our method. These results show that the C-N coupling strategy is an efficient way to assemble symmetrical and unsymmetrical aromatic azo derivatives, circumventing the formation of homocoupled azo by-products.…”

Volume Conserving Geometric Isomerization of Encapsulated Azobenzenes in Ground and Excited States and as Radical Ion

“…Trans -azobenzenes 1 – 5 (Figure ) were synthesized, purified, and characterized by methods reported in the literature. , Complexation of 1 – 5 with OA in aqueous solution was achieved as outlined in the Supporting Information. Characteristic changes in the 1 H NMR signals of the host OA and the upfield shifts of the signals due to para -alkyl groups (CH 2 and CH 3 ) of the guest (note signals in the region of δ 5.5–8 and below 0 ppm, respectively, in Figure ) in the Na 2 B 4 O 7 –D 2 O solution containing 1 – 5 and OA confirmed the inclusion of the former within OA. , The continuous change in the 1 H NMR spectra with addition of the guest to the OA solution that ended with 0.5 equiv of the guest suggested ABs formed stable 1:2 complexes with OA (guest@OA 2 ) (Figures S1–S5).…”