Reversible conversion of valence-tautomeric copper metal–organic frameworks dependent single-crystal-to-single-crystal oxidation/reduction: a redox-switchable catalyst for C–H bonds activation reaction

Upon single-crystal-to-single-crystal (SCSC) oxidation/reduction, reversible structural transformations take place between the anionic porous zeolite-like Cu(I) framework and a topologically equivalent neutral Cu(I)Cu(II) mixed-valent framework. The unique conversion behavior of the Cu(I) framework endowed it as a redox-switchable catalyst for the direct arylation of heterocycle C-H bonds.