Dual-mode operation of a bistable [1]rotaxane with a fluorescence signal

We report the operation of a ferrocene-based bistable [1]rotaxane that can work in two parallel platforms. In an "active" signal mode, the relative mechanical movement of its ring and thread in response to external acid-base-stimuli can result in a remarkable fluorescence signal output observed by the naked eye, whereas no obvious fluorescence change occurred in a "silent" signal mode after oxidation. Its fluorescence responses to the different combinations of DBU and/or Fe(ClO4)3 corresponds to an INHIBIT logic gate.