The effect of force on thermodynamics and kinetics of single molecule reactions.
The usual variables chemists use to affect a chemical reaction are temperature and pressure. We consider here an additional variable: force, F. By attaching a molecule to the tip of a cantilever of an atomic force microscope, or to a bead in a laser light trap, we can control the force on a single molecule. This mechanical force can drive a reaction to completion, or stabilize the reactants. Force changes the thermodynamic stability of a molecule; it can thus increase or decrease the free energy change for the reaction. Force can also speed or slow rates of reactions; it changes the free energy of activation of the reaction.
Tinoco
Ignacio
I
Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA. intinoco@lbl.gov
Bustamante
Carlos
C
D007700:Kinetics; D011312:Pressure; D013696:Temperature; D013816:Thermodynamics