Probing the tolerance of cucurbit[7]uril inclusion complexes to small structural changes in the guest

The binding properties of the cucurbit[7]uril host with three structurally related ferrocene-containing guests, ferrocenyltrimethylammonium, ferrocenylmethyltrimethylammonium and ferrocenylethyltrimethylammonium, have been investigated using ¹H NMR spectroscopy, mass spectrometry, voltammetry and computational methods. The experimental and computational data indicate that the stability of the cucurbit[7]uril inclusion complexes is relatively insensitive to the number of methylenes connecting the trimethylammonium and the ferrocenyl groups, although some of their properties are affected in significant ways.