Insight into Unusual Downfield NMR Shifts in the Inclusion Complex of Acridine Orange with Cucurbit[7]uril (Eur. J. Org. Chem. 29/2009)

Abstract The cover picture shows the formation of the inclusion complex of acridine orange (AO) with cucurbit[7]uril (CB[7]) and the unusual downfield NMR shifts of the proton resonances. This shift is the net result of large downfield shifts arising from the deaggregation of AO aggregates followed by small upfield shifts resulting from the inclusion of AO into the CB[7] cavity. The background shows the color change of the aqueous AO solution from yellow to green in the absence and presence of CB[7]. Details are discussed in the article by J. Ma, X. Du et al. on p.4931 ff.