A novel compound, [Cu(bimb)](2)(HPW(12)O(40)) x 3 H(2)O (bimb = 1,4-bis(imidazol-1-ylmethyl)biphenyl) with a polyoxometalate-encapsulated 3D metal-organic pseudo-rotaxane framework that can be described as a 2-fold dianet topology showing well-defined 1D nano-scale tunnels, has been synthesized hydrothermally, and its de-/rehydration behavior has been investigated.