Tuning the Intercage Distance in Charge-Regulated Blackberry-Type Assemblies through Host-Guest Chemistry

Chemistry. 2019 Apr 17;25(22):5803-5808. doi: 10.1002/chem.201900800. Epub 2019 Mar 27.

Abstract

Charged or neutral adamantane guests can be encapsulated into the cavity of cationic metal-organic M6 L4 (bpy-cage, M=PdII (2,2'-bipyridine), L=2,4,6-tri(4-pyridyl)-1,3,5-triazine) cages through hydrophobic interaction. These encapsulations can provide an approach to control the net charge on the resulting cage-guest complexes and regulate their charge-dominated assembly into hollow spherical blackberry-type assemblies in dilute solutions: encapsulation of neutral guests will hardly influence their self-assembly process, including the blackberry structure size, which is directly related to the intercage distance in the assembly; whereas encapsulating negatively (positively) charged guests resulted in a shorter (longer) intercage distance with larger (smaller) assemblies formed. Therefore, the host-guest chemistry approach can be used to tune the intercage distance accurately.

Keywords: host-guest systems; intercage distances; macroions; metal-organic cages; self-assembly.