Post-assembly Modification of Phosphine Cages Controls Host–Guest Behavior

Abstract

We report the design, synthesis and post-assembly modification of a new phosphine-paneled supramolecular cage framework, whose anion binding ability can be modified rationally through selective post-assembly functionalization. The parent phosphine-paneled cage can be modified in situ through oxidation, methylation, or auration. These covalent and coordinative modifications to the exterior of the cage strongly influence the guest binding properties of the host. X-ray data for 4 (CCDC 1900372) X-ray data for 11 (CCDC 1900370) X-ray data for 12 (CCDC 1900371

Confined space design by nanoparticle self-assembly

“…74,75 Notably, as already reported for molecular cages, guests uptake and release can be regulated also using post-assembly modifications. 100 For instance, it is possible to encapsulate, during the assembly process, molecules able to react with the inner cavities functional groups and trigger the aimed modification to tailor the cavities features and binding properties in situ. Moreover, as shown by Harraq et al, SP post-assembly modification via external stimuli can lead to SP reconfiguration, modulating guest's uptake and SP behaviour, thus allowing a single architecture to perform a variety of functions.…”

Emerging Spacers‐Based Ligands for Supramolecular Coordination Complexes

“…Nitschke and co‐workers reported a new M 4 L 4 supramolecular metallacage framework containing phosphine based spacer, tris(4‐(4‐(pyridin‐2‐yl)‐1H‐1,2,3‐triazol‐1‐yl)phenyl)phosphine (L 35 ) and Ni(II)/Fe(II)/Zn(II) [ 35 a ] 8+ [74] . The cages adopt tetrahedron geometry with a tricoordinated phosphorus center at each face.…”

Covalent Post‐Assembly Modification: A Synthetic Multipurpose Tool in Supramolecular Chemistry

“…N,N′-dimethyl-4,4′-bipyridinium ( 18), N,N′dimethylbipyridinium-4,4′-ethylene (19), or bipyridinium dithienylethene (DTE) (20), allowing electron donor-acceptor complexes to form between dopamine methacrylamide and the imprinting template. The mixture was then polymerized to form polyacrylamide hydrogels that were cooperatively cross-linked with bis-acrylamide and dopamine-template-dopamine complexes (Scheme 6).…”

“…One of the key features of PAM is the introduction of functional groups into self-assembled complexes where preassembly functionalization is impractical (e.g., due to poor reactive site selectivity) [19] or fails to preserve the self-assembled structure. [20] An increasing number of examples have been reported where PAM has been used to modify important properties of supramolecular complexes-from host-guest interactions [21] to hydrolytic stability [22] to spin-crossover properties. [23] PAM has also been used to construct seemingly impossible interlocked and topologically strained molecules, [24] covalently 'lock-down' metastable complexes, [25] and induce controlled structural transformations between different selfassemblies.…”