Thermodynamic features and environmental effects in a two-states molecular device under strict electrochemical control
Costantino Zazza1 , Giordano Mancini1, 2, Nico Sanna1 and Massimiliano Aschi3
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Supercomputing Centre for University and Research, Caspur, via dei Tizii 6/b, 00185 Rome, Italy |
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CNR-IMIP sezione di Bari, c/o Dipartimento di Chimica, Università di Bari, via Orabona 4, Bari, Italy |
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Dipartimento di Chimica, Ingegneria Chimica e Materiali, Università di L’Aquila, via Vetoio (Coppito 1), 67010 L’Aquila, Italy |
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Costantino Zazza (Corresponding
author) |
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Massimiliano Aschi (Corresponding
author) |
Received: 10 November 2008 Accepted: 29 January 2009 Published online: 17 February 2009
Abstract The thermodynamic features of a synthetic molecular thread, recently proposed acting as an electrochemically-driven two-states molecular device, have been systematically investigated by means of nanoseconds time-scale classical molecular dynamics (MD) simulations and basic statistical mechanics relations. Results clearly suggest that the accessible conformational space of such a potential molecular switch shows a strong environmental dependence: the reversible molecular switching mechanism observed in liquid solution is effectively suppressed when the synthetic thread is hypothesized working in vacuo. Such a result has been related to a subtle energetic/entropic balance experienced by the whole system (solute and solvent) during the intramolecular conformational transition of the molecular thread, in presence and in absence of the solvent.
Keywords Molecular machines and devices - Environmental effects