Water soluble [5]rotaxane and [5]pseudorotaxane based on cucurbit[6]uril and anchored to a meso-tetraphenyl porphyrin have been synthesized and characterized by spectroscopic methods (1H-NMR, 13C-NMR and UV), and by elemental analysis, and mass spectrometry. The preliminary results of the pH-driven switching properties of [5]rotaxane investigated through 1H-NMR spectroscopy are reported. These results were compared with those obtained from a model porphyrin, which was prepared by the de-threading cucurbit[6]uril from [5]pseudorotaxane under basic conditions. © Springer 2006.