Two-Photon Chemistry of Small Organic Chromophores

通常，分子可以通过吸收具有与这两种状态之间的能量差相匹配的能量的光（或光子）而被诱导从其正常基态进入激发态。 然而，正如诺贝尔奖获得者玛丽亚·戈佩特·迈耶（Maria Goeppert Mayer）在20世纪30年代所预测的那样，从基态到激发态的变化有时可以（取决于分子的性质）使用两个光子来诱导，每个光子在称为双光子吸收的过程中具有大约一半的所需能量。由于双光子吸收（2PA）比传统的单光子吸收（1PA）具有几个优点，因此对这种现象有强烈的兴趣：由于更高的穿透能力，2PA所需的能量更低，与生物系统中的光化学更相容，并且对双光子的要求提供了更大的照射微观区域的能力，从而提高了照射的准确性。 这些优点导致了双光子化学在从健康相关领域（光动力疗法）到高科技领域（3D数据存储）的各种领域中的广泛应用。 我们对双光子光化学的研究涉及发现新的有机分子，这些分子具有双光子吸收的能力，并且具有一些潜在的功能，特别是在健康相关领域。 我们的方法是迭代的，其中我们检查基线化合物的双光子吸收能力，然后使用合成有机化学进行合理的修改，以创建具有更好性能的分子。我们创造的化合物有望为生物系统中的光笼和荧光探针领域带来显着的好处。 这项工作的其他好处也是显而易见的，特别是它将为加拿大年轻人提供培训。 这项研究教授学生基本的化学技能，以及激光技术等高科技领域的技能。 还提供了一个智力技能，如创造性的解决问题的技能，允许发展和蓬勃发展的环境。

Normally, a molecule can be induced to go from its normal ground state to an excited state by absorbing light (or a photon) with energy that matches the difference in energy between those two states. However, as predicted by Nobel laureate Maria Goeppert Mayer in the 1930's, the change from ground state to excited state can sometimes (depending on the properties of the molecule) be induced using two photons with each photon having about half the needed energy in a process called two-photon absorption. There is intense interest in this phenomena, since two-photon absorption (2PA) has several advantages over the more conventional one-photon absorption (1PA): the lower energy needed for 2PA is more compatible with photochemistry in biological systems due to the higher penetration abilities, and requirement for two-photons provides a much greater ability to irradiate microscopic areas, thus increasing the accuracy of irradiation. These advantages have led to a wide range of applications of two-photon chemistry in diverse areas ranging from health related fields (photodynamic therapy) to high tech fields (3D data storage). Our research into two-photon photochemistry involves discovering new organic molecules that have the ability to undergo two-photon absorption and that have some potential function, especially in health related fields. Our method is in iterative one, in which we examine the two-photon absorbing ability of a baseline compound, and then make rational modifications using synthetic organic chemistry to create a molecule that has better properties. The compounds we create are expected to bring significant benefits to the areas of photocages and fluorescent probes in biological systems. Other benefits of this work are also apparent, especially with regards to the training it will provide to young Canadians. The research teaches students basic chemistry skills, as well as skills in high tech areas such as laser technology. An environment in which intellectual skills, such as creative problem solving skills, are allowed to develop and flourish is also provided.