Postassembly Modification of Interior Spaces Within M12L24 Nanospheres

We described a procedure for the quantitative postassembly modification of the confined space within M₁₂L₂₄ nanospheres. Nanospheres with covalent linked interior pyridinium-carboxyaldehydes are prepared. These groups form imines with amine derivatives. The describe strategy establishes guidelines for postmodification of supramolecular systems, thus providing new opportunities for unique confined spaces.

Post assembly modification (PAM) of coordination-based supramolecular self-assemblies has developed in the past 10 years as a tool that allows expansion of the chemical diversity available in supramolecular synthesis. In this contribution we apply PAM to enable the creation of M₁₂L₂₄ nanospheres with unique interior spaces. We introduce alkyl N-pyridinium carboxy aldehydes (ANCA) as ideal orthogonal functional group for PAM. The herein presented nanospheres undergo quantitative PAM with a variety of aniline derivatives, allowing the creation of hydrophobic, chiral, catalytic, and other confined spaces. As the parent spheres can be easily characterized before PAM, this methodology not only allows for the preparation of highly desirable multifunctional confined spaces but also serves with its post modulation possibilities as a fast and efficient tool for screening secondary interactions and confined spaces on probes of interest.