Fig. 3: Host−guest chemistry of metallacage 4.

a Cartoon representations of the complexation between 4 and guests. b–l Partial 1H NMR (600 MHz, CD3CN, 295 K) and m–s 31P{1H} NMR (243 MHz, CD3CN, 295 K) spectra of metallacage 4, guests G1–G6 and their related host–guest complexes. [Host] = [Guest] = 2 mM. t The binding constants of 4⊃G1, 4⊃G2, 4⊃G3 and 4⊃G4.