Molecular Recognition within a Self-Assembled Cylindrical Host

Abstract

A change in geometry is necessary on entry into the capsule: a supramolecular associate approximately 1.8 nm long (see schematic representation), which consists of two halves stabilized by hydrogen bonds, influences the intra- and intermolecular interactions of the guest molecules encapsulated. Thus tertiary amides and anilides such as 1, which exist in solution preferably as E rotamers, are fixed in the Z conformation inside the capsule for steric reasons.

Self‐Assembled Nanoreactors

“…In a similar fashion, Rebek has used the hydrogen-bonded capsule 26-26 (see Figure 4) to stabilize a tertiary anilide in its Z-configuration. 107 Encapsulation can stabilize labile oligomers, which are formed in situ by the reaction of smaller molecular components. An illustrative example is the use of coordination cages as confined reaction chambers for the condensation of trialkoxysilanes.…”

Chemical amplification with encapsulated reagents

“…Specifically, deuterated mesitylene is appropriate for most guests and provides a convenient solvent for NMR spectroscopy of the encapsulation complexes. The capsule distinguishes shape and size in the molecular recognition of potential guests (10,11). For example, trans stilbene 2 is encapsulated but cis stilbene 3 is not (Eq.…”

Control of nanospaces with molecular devices

“…The isomerization of the long and narrow trans - 1 (Figure 1) causes its predictable folding to the shorter and wider cis - 1 . For the cylindrical capsule 2˙2 ,xv only the trans form can be accommodated and it provides a good fit of guest in the host, as might be expected from its affinity for the nearly isosteric benzanilides,xvi and stilbenes xvii. We arranged a competition between trans - 1 and n -tridecane in deuterated mesitylene.…”