Tinoco Ignacio, Bustamante Carlos
Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA.
Biophys Chem. 2002 Dec 10;101-102:513-33. doi: 10.1016/s0301-4622(02)00177-1.
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.
化学家用来影响化学反应的常见变量是温度和压力。我们在此考虑另一个变量：力，F。通过将一个分子连接到原子力显微镜悬臂的尖端，或者连接到激光光阱中的珠子上，我们可以控制作用在单个分子上的力。这种机械力可以驱动反应完成，或者使反应物稳定。力会改变分子的热力学稳定性；因此它可以增加或减少反应的自由能变化。力还可以加快或减慢反应速率；它改变反应的活化自由能。
