Rewiring Chemical Networks Based on Dynamic Dithioacetal and Disulfide Bonds

Abstract

The control of the connectivity between nodes of synthetic networks is still largely unexplored. To address this point we take advantage of a simple dynamic chemical system with two exchange levels that are mutually connected and can be activated simultaneously or sequentially. Dithioacetals and disulfides can be exchanged simultaneously under UV light in the presence of a sensitizer. Crossover reactions between both exchange processes produce a fully connected chemical network. On the other hand, the use of acid, base or UV light connects different nodes allowing network rewiring.

Engineering multilayer chemical networks

“…Both mild Lewis acids stopped the disulde exchange and selectively catalyzed dithioacetal exchange; however, the equilibrium was reached in 24 h only with tin(II) triate. The exchange, formation or hydrolysis of dithioacetals has also been achieved using photoirradiation in the presence of photosensitizers such as 9,10-dicyano anthracene (DCA) 36 or rose bengal. 49,50 When applied to our starting solution of 1A1, B1, 11 and 2H, DCA/UV light induced a very slow exchange of dithioacetals and disuldes along with extensive decomposition ( Table 1, entry 11).…”

“…Dithioacetal exchange has been recently introduced into the eld of dynamic covalent chemistry. Although so far TFA has been the only Brønsted acid used to catalyze the reaction, 36,40,41 stronger acids may be more convenient to speed up the exchange ( Table 1, entries 3 and 4).…”

“…The combination of communicating reactions that can be sequentially activated represents a special study case since they give rise to multilayer networks. 36 In multilayer networks, each molecular network is described as a "layer" and the different layers are connected through common nodes, i.e. connector molecules involved in more than one reaction (Fig.…”

“…20,28 The only example of a two-layer dynamic chemical network reported is based on the sequential activation of dithioacetal and disulde exchanges. 36 Addition of a third communicating reaction, such as thioester exchange, and the implementation of different reaction conditions to selectively activate the reactions, individually or in pairs, may open the door towards further exploration of multilayer systems.…”

Design of Active Interfaces Using Responsive Molecular Components

“…On the other hand, the response time is limited by the rate of the reaction. Typical examples include dynamic covalent bonds such as boronate esters, hydrazones, and disulfides, which respond to pH changes, the addition of competing reagents, or (in some cases) irradiation or redox reactions. Noncovalent interactions such as hydrogen bonding, pi‐stacking, or host–guest chemistry are also highly sensitive to even minor changes in pH or temperature, so that the properties of supramolecular materials and their interfaces can be easily tuned by external stimuli …”