近年来,棘轮机制已经改变了对随机分子系统的理解和设计-生物,化学和物理-摆脱了在1990年代和2000年代初期主导分子动力学思想的机械宏观类比(例如活塞,弹簧,etc),支持当今分子科学失衡研究的更多与规模相关的概念。Ratcheting已将分子纳米技术确立为能量转导和代谢的研究前沿,并实现了生物分子机械的逆向工程,提供有关分子“行走”和基于轨道的合成器如何操作的见解,化学反应的加速如何使能量被催化剂转化,以及动态(超)分子系统如何摆脱平衡。分子棘轮机制在生物学中的认识,以及他们在合成系统中的发明,在超分子化学等不同领域被证明具有重要意义,系统化学,动态共价化学,DNA纳米技术,聚合物和材料科学,分子生物学,多相催化,endergonic合成,和化学科学的许多其他分支。简单地说,棘轮机构给化学方向。动力学不对称,由棘轮的结果量化,是结构不对称性(即手性)的动态对应物。鉴于棘轮机制的无处不在,这当然也同样重要。
Over the last two decades ratchet mechanisms have transformed the understanding and design of stochastic molecular systems-biological, chemical and physical-in a move away from the mechanical macroscopic analogies that dominated thinking regarding molecular dynamics in the 1990s and early 2000s (e.g. pistons, springs, etc), to the more scale-relevant concepts that underpin out-of-equilibrium research in the molecular sciences today. Ratcheting has established molecular nanotechnology as a research frontier for energy transduction and metabolism, and has enabled the reverse engineering of biomolecular machinery, delivering insights into how molecules \'walk\' and track-based synthesisers operate, how the acceleration of chemical reactions enables energy to be transduced by catalysts (both motor proteins and synthetic catalysts), and how dynamic systems can be driven away from equilibrium through catalysis. The recognition of molecular ratchet mechanisms in biology, and their invention in synthetic systems, is proving significant in areas as diverse as supramolecular chemistry, systems chemistry, dynamic covalent chemistry, DNA nanotechnology, polymer and materials science, molecular biology, heterogeneous catalysis, endergonic synthesis, the origin of life, and many other branches of chemical science. Put simply, ratchet mechanisms give chemistry direction. Kinetic asymmetry, the key feature of ratcheting, is the dynamic counterpart of structural asymmetry (i.e. chirality). Given the ubiquity of ratchet mechanisms in endergonic chemical processes in biology, and their significance for behaviour and function from systems to synthesis, it is surely just as fundamentally important. This Review charts the recognition, invention and development of molecular ratchets, focussing particularly on the role for which they were originally envisaged in chemistry, as design elements for molecular machinery. Different kinetically asymmetric systems are compared, and the consequences of their dynamic behaviour discussed. These archetypal examples demonstrate how chemical systems can be driven inexorably away from equilibrium, rather than relax towards it.