Controlled disassembling of self-assembling systems: toward artificial molecular-level devices and machines

Abstract

Investigations on self-assembling/induced-disassembling systems have led to the design of molecular-level devices capable of performing a variety of functions. Some of the work carried out in this field is illustrated.

Figure 1

Schematic representation of a self-assembling/induced-disassembling/reset process that can be exploited to design molecular-level devices.

Figure 2

Acid/base controlled plug-in/plug-out of the (9-anthracenyl)benzylammonium ion 2H⁺ with the (±)-binaphthocrown ether 1. The occurrence of photoinduced energy transfer in the plug-in state is schematized.

Figure 3

Components of a three-pole supramolecular switch and schematic representation of the ranges of electrochemical stability of the three states available to the system.

Figure 4

Light-driven dethreading of pseudorotaxanes by excitation of a photosensitizer (a) contained as a stopper in the wire-type component, and (b) incorporated in the macrocyclic ring.

Figure 5

Controllable detreading/rethreading of a pseudorotaxane based on a trans-cis photoisomerization reaction.

Figure 6

Schematic representation of a chemical system (P) which performs the AND (a), OR (b), and XOR (c) logic operations under the action of two chemical inputs (X and Y). The truth tables of such operations are also shown, along with their representations based on electric circuit schemes.

Figure 7

Schematic representation of the threading/dethreading pattern of pseudorotaxane [7⋅8]²⁺, which corresponds to an XOR logic function.