abstract
Despite their hydrophobic surfaces with localized pi-holes and rigid well-defined architectures providing a scaffold for preorganizing binding motifs, fullerenes remain unexplored as potential supramolecular host platforms for the recognition of anions. Herein, we present the first example of the rational design, synthesis, and unique recognition properties of novel fullerene-functionalized halogen-bonding (XB) heteroditopic ion-pair receptors containing cation and anion binding domains spatially separated by C-60. Fullerene spatial separation of the XB donors and the crown ether complexed potassium cation resulted in a rare example of an artificial receptor containing two anion binding sites with opposing preferences for hard and soft halides. Importantly, the incorporation of the C-60 motif into the heteroditopic receptor structure has a significant effect on the halide binding selectivity, which is further amplified upon K+ cation binding. The potassium cation complexed fullerene-based receptors exhibit enhanced selectivity for the soft polarizable iodide ion which is assisted by the C-60 scaffold preorganizing the potent XB-based binding domains, anion-pi interactions, and the exceptional polarizability of the fullerene moiety, as evidenced from DFT calculations. These observations serve to highlight the unique properties of fullerene surfaces for proximal charged guest binding with potential applications in construction of selective molecular sensors and modulating the properties of solar cell devices.
keywords
BASIS-SETS; ANION; CHEMISTRY; CONSTRUCTION; RECEPTORS; TRANS-1; DESIGN; STATES
subject category
Chemistry
authors
Bak, KM; Marques, I; Kuhn, H; Christensen, KE; Félix, V; Beer, PD
our authors
Vítor Félix
Associate Professor with AggregationProjects
CICECO - Aveiro Institute of Materials (UIDB/50011/2020)
CICECO - Aveiro Institute of Materials (UIDP/50011/2020)
Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)
acknowledgements
K.M.B. acknowledges EPSRC for postdoctoral funding (EPSRC Grant EP/P033490/1). H.K. thanks the EPSRC for studentship funding (EPSRC Grant EP/R513295/1). The theoretical studies were developed within the scope of the project CICECO-Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020, and LA/P/0006/2020, financed by national funds through the FCT/MCTES (PIDDAC). We also thank Diamond Light Source for an award of beamtime (CY26802).