Stopped-flow Spectrometer for Supramolecular Dynamics Studies

停流光谱仪用于测量以毫秒为单位发生的化学反应的速度。测量发生在毫秒内的化学反应的动力学太快了，不能用手工混合溶液来研究。在停流实验中，通过对注射器施加压力，两个注射器中包含的两种不同的溶液在混合室中混合。化学反应之后，测量消失的试剂或出现的产物的吸收或发射(荧光)。所要求的系统包括分析同时或按顺序发生多个反应的数据的能力。停流光谱仪是我们研究超分子动力学的中心设备。超分子化学在复杂性和功能性方面占据了单个分子和宏观系统之间的空间。超分子体系总是可逆的，随着分子构造物和超分子之间的不断相互转化。一个系统中的各种物种共存并相互竞争。任何超分子体系的表征都需要研究物种之间的相互转化，而这种信息只能从动力学研究中获得，在动力学研究中，我们观察到系统向平衡状态演化。我的研究计划的目标是了解复杂性的增加如何影响每个系统的结果，以便创建一个概念框架，说明如何有目的地利用系统的复杂性来实现在生活系统中看到的各种紧急特性。这一概念框架可应用于功能材料的合理设计。在一个研究项目中，我们将确定建立一个系统的最低要求，在这个系统中，组件可以保持远离平衡，同时以光的形式向系统提供能量。这些研究依赖于一类多种多样的大环宿主(葫芦巴[n]尿素)的主客体化学。第二个研究领域侧重于了解水凝胶是如何形成的，以及这些材料的结构如何影响这些材料中的流动性。第一个项目推进了对超分子体系功能的基本认识。这一理解适用于系统化学领域，该领域的重点是拥抱复杂性，以解释无法从研究单个分子之间相互作用的性质中预测出的新性质的出现。第二个项目将对任何凝胶的设计产生影响，如果凝胶的功能需要分子在材料内部以及材料与外部环境之间的运动。第二个项目的成果将导致开发更好的功能材料，例如开发定制的药物输送系统。

The stopped flow spectrometer is used to measure the speed of chemical reactions that occur in milliseconds. Measurements of the kinetics for chemical reactions that occur in milliseconds are too fast to be studied by mixing solutions by hand. In a stopped-flow experiment two different solutions contained in two syringes are mixed in the mixing chamber by the application of pressure to the syringes. The chemical reactions are followed by either measuring the absorption or the emission (fluorescence) for the reagents that disappear or for the products that appear. The requested system includes the ability to analyze data where multiple reactions occur simultaneously or in sequence. The stopped-flow spectrometer is the central equipment for our studies in supramolecular dynamics. Supramolecular chemistry occupies the space between individual molecules and macroscopic systems in terms of complexity and functionality. Supramolecular systems are always reversible with the continuous interconversion between molecular building blocks and supermolecules. The various species in a system co-exist and compete with one another. The characterization of any supramolecular system requires studies on the interconversion between species, and this information can only be obtained from kinetic studies, where we observe the system evolving toward its equilibrium state. The objective of my research program is to understand how increases in complexity affect the outcomes of each system in order to create a conceptual framework on how the system's complexity can be purposely exploited to achieve the types of emergent properties seen in living systems. This conceptual framework can then be applied to the rational design of functional materials. In one research project we will determine the minimum requirements to build a system where the components can be kept away from equilibrium, while energy in the form of light is provided to the system. These studies rely on the host-guest chemistry of a versatile class of macrocyclic hosts (cucurbit[n]urils). The second area of research focusses on the understanding on how hydrogels form and how the structure of these materials affects the mobility within these materials. The first project advances the fundamental understanding on the function of supramolecular systems. This understanding is applicable to the field of systems chemistry, where the focus is to embrace complexity to explain the emergence of new properties that cannot be predicted from the properties derived from the studies of interactions between individual molecules. The second project will have impact on the design of any gel where the function requires the movement of molecules within the material and between the material and the external environment. The outcome from the second project will lead to the development of better functional materials, such as the development of tailored drug delivery systems.