Fig. 2: Characterization of metal-organic capsule H1 and HF.

a The structure of the octahedral cage Co6L46+ (H1) showing the large cavity volume and robust openings. b The simulation structure of cage Co6L46+ with fluorescein encapsulated showing the relative positions. c ESIāMS spectra of metal-organic capsule H1 (1.0āmM) in a CH3CN solution. d ESIāMS spectra of H1 (1.0āmM) with fluorescein (1.0āmM) in a CH3CN solution. The inserts show the theoretical and experimental isotopic patterns of the peaks mentioned.