Adhesive π-Clamping within Synthetic Multifunctional Pores

摘要

We report the design, synthesis, and evaluation of multifunctional pores with electron-deficient naphthalenediimide (NDI) π-clamps at their inner surface for molecular recognition by aromatic electron donor-acceptor interactions (i.e., 1, Figures 1 and 2). Stimuli-responsive synthetic pores attract increasing scientific attention because of their adaptable applicability in domains such as diagnostics (multicomponent sensing), drug discovery (inhibitor screening), and so on. However, the molecular recognition motifs elaborated so far for synthetic pores focus on multiple ion pairing. Here, we introduce π-clamping by aromatic electron donor-acceptor interactions as an attractive concept to complement molecular recognition within synthetic multifunctional pores with interactions that are (a) orthogonal to ion pairing and (b) beyond reach with biological multifunctional pores. In pore 1, NDIs with their sticky, π-acidic surfaces were selected as ideal abiotic amino acid side chains (π_A) to "clamp" π-basic guest molecules (Figure 2). Flanking lysines (K) were added for assistance with ion pairing as in the previous pore 2 without π-acidic clamps.