| Abstract
| - The template effects exerted by compounds 3,5, 6, and 8 in the ring closure reaction of the trication 13+to yield the [2]pseudorotaxanes 154+ and 174+ and the [2]rotaxanes 184+ and 204+ have been quantitatively evaluatedin acetonitrile at 62 °C by UV/vis spectrophotometry. Therate of ring closure of the trication 13+ largely increases inthe presence of the templates up to a maximum of ca. 200times in the case of 5 at a concentration of ca. 0.08 M. Theresults indicate that, in the self-assembly of a rotaxane, thetemplate effect of the guest is lowered by the presence oftwo large stoppers (triisopropylsilyl) at the end of the linearchains; this effect is more important the shorter the chainand can be mainly ascribed to steric effects. Previouslyhypothesized entropic effects appear to be of lesser importance.
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