Experimental Study of Nonadiabatic Dynamics in Photoinduced Reactions of Complexes

在原子或分子之间的碰撞中，重原子核的动量可能会提供反应发生的驱动力(或能量)。随后，电子在原子或分子的原子核之间的重新分配导致化学键的形成或断裂。这一解释是合理的，因为与电子相比，原子核的质量要大得多。然而，在化学中有这样的例子，在化学转变的过程中，是电子的运动驱动了原子核。其结果是形成了一种原本可能出人意料的产品。这项工作的目的是研究这些过程的机制。下面将描述这些反应的两个有代表性的例子。这涉及一种用于治疗癌症的药物的化学成分和一种相当不寻常的反应机制。(1)光动力疗法：一种治疗癌症和其他疾病的实验性疗法。氧气分子在人体的血液和组织中被吸收。能量转移到这些分子将产生一种高度活性的氧气，可以用来摧毁患病的细胞。这可以通过氧与另一种高能分子的碰撞来实现。另一种分子是一种给患者服用的药物，它通过吸收光能而被激活。合适的光源是激光，通过插入患者体内的光纤光导，光可以直接传输到肿瘤部位的药物。(2)鱼叉反应：碱金属(即Li、Na、K)与卤素(氟、氯、溴分子)的反应。该反应的机理涉及将电子从碱金属原子转移到卤素分子。这种现象被称为鱼叉效应，因为它是在原子和分子相距很远的时候被观测到的。电子转移形成的离子对(鱼叉)的静电吸引导致卤素分子卷进碱金属。这项研究旨在发现有关电子转移事件的基本信息，并将扩展到涉及从生物分子的金属中心进行电荷转移的化学过程。在被称为物理化学的化学的一个分支学科中，物理学原理用于研究化学反应。同样的方法将应用在这项工作中，使用涉及生物学和医学中感兴趣的分子或机制的化学反应的例子。这是研究这一领域的一种新方法，它将提供独一无二的原始数据。

During a collision between atoms or molecules, the momentum of the heavy nuclei might be expected to supply the driving force (or energy) for a reaction to take place. Subsequently, the redistribution of electrons between the nuclei of the atoms or molecules leads to the formation or breaking of chemical bonds. This explanation is justified by the much heavier mass of the nuclei compared with electrons. However, there are examples in chemistry where it is the motion of electrons that drive the nuclei on the course of a chemical transformation. The result is the formation of a product that might otherwise have been unexpected. It is the object of this work to examine the mechanism for these processes. Two representative examples of these reactions will be described below. These involve the chemistry of a drug used to treat cancer and a rather unusual reaction mechanism.(1) Photodynamic Therapy: an experimental treatment for patients with cancer and other diseases.Oxygen molecules are absorbed in the blood and tissue of a human body. The transfer of energy to these molecules will generate a highly reactive form of oxygen that can be used for the destruction of diseased cells. This can be achieved in collisions between oxygen and another highly-energetic molecule. This other molecule is a drug that has been administered to a patient and it has been activated by the absorption of energy from light. A suitable source of light is a laser and, using a fibre-optic light guide inserted into the patient's body, the light can be delivered directly to the drug in the location of a tumor.(2) The Harpooning Reaction: the reactions of alkali metals (i.e. Li, Na, K) with halogens (fluorine, chlorine, bromine molecules).The mechanism of this reaction involves the transfer of an electron from an alkali-metal atom to a halogen molecule. This event has been referred to as harpooning because it is observed whilst the atom and molecules are widely spaced apart. The electrostatic attraction of the ion pair formed by the transfer of an electron (the harpoon ) results in the halogen molecule being reeled Into the alkali metal. This research is aimed at discovering fundamental information about the electron-transfer event and it will be extended to chemical processes involving charge-transfer from metal centres of biological molecules.In a sub-discipline of Chemistry referred to as Physical Chemistry, the principles of Physics are used to study chemical reactions. The same approach will be applied in this work using examples of chemical reactions involving molecules or mechanisms of interest in biology and medicine. This is a novel approach to the study of this field and it will provide unique and original data.