β-cyclodextrin
(βCyD) derivatives equipped
with aromatic
appendages at the secondary face exhibit tailorable self-assembling
capabilities. The aromatic modules can participate in inclusion phenomena
and/or aromatic–aromatic interactions. Supramolecular species
can thus form that, at their turn, can engage in further co-assembling
with third components in a highly regulated manner; the design of
nonviral gene delivery systems is an illustrative example. Endowing
such systems with stimuli responsiveness while keeping diastereomeric
purity and a low synthetic effort is a highly wanted advancement.
Here, we show that an azobenzene moiety can be “clicked”
to a single secondary O-2 position of βCyD affording 1,2,3-triazole-linked
βCyD-azobenzene derivatives that undergo reversible light-controlled
self-organization into dimers where the monomer components face their
secondary rims. Their photoswitching and supramolecular properties
have been thoroughly characterized by UV–vis absorption, induced
circular dichroism, nuclear magnetic resonance, and computational
techniques. As model processes, the formation of inclusion complexes
between a water-soluble triazolylazobenzene derivative and βCyD
as well as the assembly of native βCyD/βCyD-azobenzene
derivative heterodimers have been investigated in parallel. The stability
of the host–guest supramolecules has been challenged against
the competitor guest adamantylamine and the decrease of the medium
polarity using methanol–water mixtures. The collective data
support that theE-configured βCyD-azobenzene
derivatives, in aqueous solution, form dimers stabilized by the interplay
of aromatic–aromatic and aromatic-βCyD cavity interactions
after partial reciprocal inclusion. Photoswitching to theZ-isomer disrupts the dimers into monomeric species, offering
opportunity for the spatiotemporal control of the organizational status
by light.