Dedicated to Prof. Mario Gattuso on the occasion of his retirement
Modulation and control of the molecular features of a given receptor/substrate, and hence their supramolecular properties, by means of external, nondestructive, stimuli is still a topic of current and increasing interest, not only from a fundamental perspective but also from that of future nanodevices. [1] Light is the most appealing on/off trigger. The combination of its ready availability and easy manipulation, together with the fast rate of photochemical reactions, makes photoregulated systems particularly suited for multifaceted applications in different fields, which range from molecular optoelectronics [2] and energy conversion, [3] to the environment [4] and biomedicine. [5] Control over host-guest complexation events is one of the fundamental areas in which photoresponsive centers play a key role. In this respect, the reversible trans-cis photoisomerization of azobenzene moieties has proved to be one of the most convenient tools for inducing conformational modifications that may influence functional properties at the nanoscale level. [6] Incorporation of an azobenzene moiety either into a receptor framework [7] or into a substrate [8] has provid-
[a] Dr.