Reversible solid-gas chemical equilibrium between a 0-periodic deformable molecular tecton and a 3-periodic coordination architecture.

The reversible crystal transformation between a hexagonal (R3[combining macron]) porous coordination architecture [Cu(L)(2)](n) (L = 3-(pyridin-4-yl)-5-(pyrazin-2-yl)-1H-1,2,4-triazole), and a monoclinic (C2/c) molecular tecton [Cu(L)(2)(H(2)O)], was chemically implemented and structurally interpreted.