A V-type molecule comprising a 2-[2-[4-(dimethylamino)phenyl]ethenyl]pyridinium cyanine branch and a p-aminophenoxy ethyl side arm was synthesized and can form quite different [2]pseudorotaxanes with cucurbit[7]uril (CB[7]) as a model thread in aqueous solution. The CB[7] ring can be switched reversibly from the cyanine branch to the aminophenoxy ethyl side arm by protonation of the aniline group, and the color of the solution was changed from orange red to yellow.