Guest‐Reaction Driven Cage to Conjoined Twin‐Cage Mitosis‐Like Host Transformation

Abstract We report here a guest‐reaction‐induced mitosis‐like host transformation from a known Pd 4 L 2 cage 1 to a conjoined Pd 6 L 3 twin‐cage 2 featuring two separate cavities. The encapsulation of 1‐hydroxymethyl‐2‐naphthol ( G1 ), a known ortho‐quinone methide (o‐QMs) precursor, within the hydrophobic cavity of cage 1 is found crucial to realize the cage to twin‐cage conversion. Confined G1 molecules within the nanocavity undergo self‐coupling dimerization reaction to form 2,2′‐dihydroxy‐1,1′‐dinaphthylmethane ( G2 ) which then triggers the cage to twin‐cage mitosis. The same conversion also proceeds, in a much faster rate, via the direct templation of G2 , confirming the induced‐fit transformation mechanism. The structure of the ( G2 ) 2 ⊂ 2 host–guest complex has been established by X‐ray crystallographic study, where cis‐ to trans‐ conformational switch on one bridging ligand is revealed.