Interaction of a hemicyanine dye and its derivative with DNA and cucurbit[7]uril

Abstract

The host–guest interaction of trans-4-[4-(dimethylamino)styryl]-1-methylpyridinium iodide (DSMI) with cucurbit[7]uril (CB[7]) was investigated through fluorescence, absorption, ¹H NMR and mass spectrometry. DSMI can be included by CB[7] with 1 : 2 stoichiometry to form the DSMI/CB[7] complex, exhibiting a larger binding affinity than that of DNA. To make a comparison with DSMI, another pyridium vinyl group was introduced into the aniline ring of DSMI to get a hemicyanine derivative D2, and a ternary complex among D2, CB[7] and DNA was formed. All these provide new insights to investigate the interaction of organic dyes, CB[7] and DNA.