Dissipative Systems
M. Valentini, G. Ercolani, S. Di Stefano, Chemistry a European Journal 2024, e2023038, Early View (HOT PAPER).
When an Activated Carboxylic Acid (ACA) is employed to perturb a dynamic library of imines, the nature of the solvent has a crucial role in defining the non-equilibrium state of such library. A dissipative dynamic library in CD2Cl2, fully coupled with the decarboxylation of the ACA, or a kinetically trapped out-of-equilibrium dynamic library in CD3CN can be generated.
G. Capocasa, F. Frateloreto, S. Correale Cavallari, M. Valentini, O. Lanzalunga, S. Di Stefano Chemistry a European Journal, 2024, e202303897 (HOT PAPER, cover feature).
Time-controlled pH variations enabled by the decarboxylation of nitroacetic acid are transduced into time-controlled voltage variations. Such variations are exploited to govern the operation of simple electric devices such as LEDs or electromagnets.
A Doubly Dissipative System Driven by Chemical and Radiative Stimuli
M. Valentini, F. Frateloreto, M. Conti, R. Cacciapaglia, D. Del Giudice, S. Di Stefano, Chemistry a European Journal, 2023, 29, e2023018.
The motions of an alkali cation from and to the crown-ether moieties of different ligands (up to three) is controlled over time and in a dissipative fashion by contextually employing two orthogonal stimuli, namely a radiative one and a chemical one. When the stimuli are no longer supplied, moving from out-of-equilibrium states, the system reversibly returns to its equilibrium state.
Dissipative Systems Driven by the Decarboxylation of Activated Carboxylic Acids
D. Del Giudice, S. Di Stefano, Accounts of Chemical Research, 2023, 56, 889−899 (cover feature).
This Account describes dissipative systems based on the acid-base reaction whose operation is driven by the decarboxylation of activated carboxylic acids (ACAs). It is shown that ACAs have been used so far for time-controlling of molecular machines, host-guest systems, catalysts, smart materials and so on. Such generality is mainly due to the simplicity of the idea underlying the operation principle of ACAs, which always translates into simple experimental requirements
D. Del Giudice, M. Valentini, C. Sappino, E. Spatola, A. Murru, G. Ercolani, S. Di Stefano, Journal of Organic Chemistry, 2023, 88, 4379−4386.
2-Cyano-2-phenylpropanoic acid controls over time the conformational freedom of 2-Dimrthylaminobiohenyl structures in a dissipative fashion. The operation of the sysytem is allowed by the proton sharing of two basic functions present in the molecular scaffold
Autonomous Soft Robots Empowered by Chemical Reaction Networks
G. Fusi, D. Del Giudice, O. Skarsetz, S. Di Stefano, A. Walther, Advanced Materials, 2023 , 35, 2209870. (back cover)
By using a pH-flip based on a self-decarboxylating acid, transient control of a soft actuator is achieved. This method of control allows for tuning of actuation amplitude and duration, and can be coupled to further reactions for more complex self-regulation. Autonomous operation and unique “fire and forget” time-programmed applications are demonstrated.
Dissipative Dynamic Libraries (DDLs) and Dissipative Dynamic Combinatorial Chemistry (DDCC)
D. Del Giudice, E. Spatola, M. Valentini, G. Ercolani, S. Di Stefano, ChemSystemsChem 2022, e202200023 (VERY IMPORTANT PAPER, cover feature, TOP 10% of highly downloaded from ChemSystemsChem during its first 12 months of publication).
In this Concept the fundamental features of Dissipative Dynamic Libraries (DDLs) maintained out-of-equilibrium by the consumption of a fuel are described with particular emphasis on the factors that govern the composition of the libraries over the time.
Chemical Tools for the Temporal Control of Water Solution pH and Applications in Dissipative Systems
D. Del Giudice, F. Frateloreto, C. Sappino, S. Di Stefano, European Journal of Organic Chemistry, 2022, e202200407 (VERY IMPORTANT PAPER, Top 10 of highly cited works from Eur. J. Org. Chem. From 1 Jan 2022 to 31 Dec 2023, 1st cover page).
The chemical reagents and methodologies (tools) employed for accurately and precisely programming over time the pH of a water solution are described in detail. For each tool, a number of selected examples is reported in order to show its feasibility and usefulness.
F. Frateloreto, F. Tavani , M. Di Berto Mancini, D. Del Giudice, G. Capocasa, I. Kieffer, O. Lanzalunga, S. Di Stefano, P. D’Angelo, Journal of Physical Chemistry Letters, 2022, 13, 5522−5529.
Dissipative Dynamic Covalent Chemistry (DDCvC) Based on the Transimination Reaction
D. Del Giudice, M. Valentini, G. Melchiorre, E. Spatola, S. Di Stefano, Chemistry a European Journal, 2022, 28, e202200685. (HOT PAPER)
Dissipative dynamic libraries (DDLs) of imines are generated by addition of 2-cyano-2-(4’-chloro)phenylpropanoic acid employed as a chemical fuel to equilibrated dynamic libraries (DLs). At the addition of the fuel the initial composition of the library dictated by the thermodynamic equilibrium is perturbed and a transient, temporal controllable, out of equilibrium state is obtained, which reverts to the initial equilibrium when the fuel is exhausted.
F. Rispoli, E. Spatola, D. Del Giudice, R. Cacciapaglia, A. Casnati, L. Baldini, S. Di Stefano, Journal of Organic Chemistry, 2022, 87, 3623-3629.
The host-guest interaction between a calix[6]arene functionalized with three amino groups (the host) and the N-methylisoquinolinium ion (the guest) is controlled over time in a dissipative fashion by means of 2-cyano-2-(4’-chloro)phenylpropanoic acid used as convenient chemical fuel.
Dissipative Control of the Fluorescence of a 1,3-Dipyrenyl Calix[4]arene in the Cone Conformation
E. Spatola, D. Del Giudice, F. Rispoli, R. Cacciapaglia, A. Casnati, L. Marchiò, L. Baldini, S. Di Stefano, Organic and Biomolecular Chemistry, 2022, 20, 132-138. (HOT ARTICLE)
The temporal control (ON/OFF/ON) of the fluorescence of a dichloromethane/acetonitrile 1:1 solution of a calix[4]arene decorated with two pyrenyl moieties at the upper rim is attained by addition of CCl3CO2H used as a convenient chemical fuel
Dissipative operation of pH-responsive DNA-based nanodevices
D. Mariottini, D. Del Giudice, G. Ercolani, S. Di Stefano, F. Ricci, Chemical Science 2021, 12, 11735–11739.
We demonstrate here the use of 2-(4-chlorophenyl)-2-cyanopropanoic acid (CPA) and nitroacetic acid (NAA) as convenient chemical fuels to drive the dissipative operation of DNA-based nanodevices.
D. Del Giudice, E. Spatola, M. Valentini, C. Bombelli, G. Ercolani, S. Di Stefano, Chemical Science 2021, 12, 7460–7466.
Predictable and time-programmable sequences of the kind pH1(high)‑pH2(low)‑pH3(high) in water solution are obtained by a judicious choice of the concentration of nitroacetic acid undergoing decarboxylation.
D. Del Giudice, E. Spatola, R. Cacciapaglia, A. Casnati, L. Baldini, G. Ercolani, S. Di Stefano, Chemistry A European Journal 2020, 26, 14954 – 14962.
The shape of the cone calix[4]arene scaffold can be controlled by means of chemical fuels. The time in which the calix[4]arene platform persists in the “locked” shape is controlled by varying nature and amount of the chemical fuel.
C. Biagini, G. Capocasa, D. Del Giudice, V. Cataldi, L. Mandolini, S. Di Stefano, Organic and Biomolecular Chemistry 2020, 18, 3687-3873. (HOT ARTICLE)
Aminolysis of the anhydride of 2-cyano-2-phenylpropanoic acid can be employed to conveniently regulate the liberation rate of the related acid which, in turn, can be used as a fuel for acid-base operated molecular machines.
C. Biagini, S. Di Stefano, Angewandte Chemie International Edition 2020, 59, 8344-8354.
Natural molecular machines require a continuous fuel supply to perform motions and/or remain in a functional state. Consequently, the aim of developing artificial devices and materials with life-type properties has motivated a growing interest in abiotic chemical fuels and in their supply modalities. Many artificial molecular machines have been developed in which the sequential addition of several chemical reagents allows the machine to perform complete cycles of motion. Only recently, examples of molecular machines whose cycles of motion are triggered by a single pulse of fuel have been reported. The latter systems are the object of this Minireview where the abiotic chemical fuels used so far to trigger the complete cycles of motion of molecular machines are described, with particular emphasis on the operation mechanism of the machine/fuel system.
C. Biagini, G. Capocasa, V. Cataldi, D. Del Giudice, L. Mandolini, S. Di Stefano, Chemistry A European Journal, 2019, 25, 15205 – 15211.
This work has been aimed at making phenomenologically autonomous the otherwise step-wise operation of a catenane-based molecular switch, chemically triggered by the decarboxylation of 2-cyano-2-phenylpropanoic acid (2). Given that any amount of 2 in stoichiometric excess with respect to the catenane is wasted in a side reaction, we resorted to the corresponding anhydride 5, whose slow hydrolysis due to adventitious water in dichloromethane continuously produces in situ the actual fuel 2. As a consequence, the machine does not require a reloading after each cycle, but switches back and forth as long as fuel is present.
P. Franchi, C. Poderi, E. Mezzina, C. Biagini, S. Di Stefano, M. Lucarini, The Journal of Organic Chemistry, 2019, 84, 9364−9368.
The back and forth motions of a crown-ether based wheel along the axis of a bistable rotaxane are triggered by the decarboxylation of2-cyano-2-phenyl
propanoic acid and detected by the oscillation of the EPR nitrogen splitting of a dialkyl nitroxide function mounted within the macrocyclic ring.
C. Biagini, S. D. P. Fielden, D. A. Leigh, F. Schaufelberger, S. Di Stefano, D. Thomas, Angewandte Chemie International Edition 2019, 2019, 58, 9876 –9880
(HOT PAPER and 1st cover page, top downloaded paper 2018-2019).
An out-of-equilibrium state of a synthetic molecular machine is used to control catalysis. A rotaxane is transiently converted from a catalytically inactive state to an
active form by CCl3CO2H. The acid decarboxylates, promoted by deprotonation by the rotaxane, returning the system to its original state and stopping catalysis. The
process allows temporal control of a coupled biomimetic reduction reaction.
Photoinduced Release of a Chemical Fuel for Acid–Base-Operated Molecular Machines
C. Biagini, F. Di Pietri, L. Mandolini, O. Lanzalunga, S. Di Stefano, Chemistry A European Journal, 2018, 24, 10122 – 10127 (HOT ARTICLE, soptlighted in Angewandte Chemie International Edition).
Photocontrol of the back and forth motions of a molecular switch is attained by use of an inactive pre‐fuel, which is transformed into the active form by irradiation with light at the proper wavelength.
C. Biagini, S. Albano, R. Caruso, L. Mandolini, J. A. Berrocal, S. Di Stefano, Chemical Science, 2018, 9, 181 – 188 (EDITOR'S CHOICE COLLECTION).
Moderate variations in the fuel structure cause large changes in the rate of the back and forth motions experienced by a chemically fuelled catenane-based switch.
J. A. Berrocal, C. Biagini, L. Mandolini, S. Di Stefano, Angewandte Chemie International Edition 2016, 55, 6997–7001.
Carboxylic acid 1 is described as a convenient fuel for the operation of a molecular switch that move under the influence of protonation-deprotonation steps. The cyclic motions of the switch take place at the sole expenses of the chemical energy supplied by the decarboxylation of 1, without recourse to additional stimuli.