Adventurous Research in Chemistry at the University of Bristol 2005

化学研究正在迅速发展，因此，化学现在通过从分子如何行为的角度看待问题来解决其他传统科学领域（如生物学）中的重要问题。人们早就知道，许多具有重要生物学意义的分子，如氨基酸和蛋白质，它们的原子排列都有自己的偏好，这种现象被称为同手性。一个分子的手性意味着，一个分子在镜子中的反射会产生另一个分子，而这个分子不能完全放在开始的分子上，就像你的右手和左手不能完全匹配一样。生物分子对特定手性形式的明显偏好长期以来一直困扰着科学家，因为制造这些分子的正常方法应该产生等量的不同手性形式，而不会对其中一种或另一种给予总体的自然偏好。人们对天然同手性的原因提出了一些建议，但这些论点中存在弱点，阻碍了它们发展成令人信服的理论。在本提案中描述的第一个项目中，提出了一种形成天然手性分子的新方法，该方法涉及将许多小分子（可能在地球上生命进化之前就存在的那种分子）连接在一起，形成称为聚合物的大分子。如果这些聚合物可以作为一个支架，其他小分子以同样的方式连接在一起，那么这些手性聚合物的复制速度就会比其他具有不同手性的分子更快。第二个项目将开发一个火柴盒大小的微型核磁共振光谱仪。核磁共振在化学中是一种非常强大的技术，它可以测量分子的形状和结构。在医学上，它被广泛应用于核磁共振扫描仪来拍摄人体器官的图像。大多数核磁共振仪器都很大（比一个人还大）、很重而且非常昂贵，因为它们需要很大的磁铁才能正常工作。在这个项目中，将建造一个更小的核磁共振机器，它使用无线技术向计算机发送信号。它将比普通的核磁共振仪器便宜得多，而且在化学实验室、工业研究实验室、制造工厂和医学实验室中作为标准设备使用起来更加方便。第三个项目侧重于化学的核心领域，即开发新的方法来制造新的、有趣的和重要的分子（称为化学或分子合成）。苯环（六个碳原子连接成六边形）存在于许多分子中，化学家希望能够控制苯环中不同碳原子之间形成新键的方式。例如，如果六边形顶端的1号碳已经与另一个原子（如氧）成键，那么与它旁边的碳原子（环上的2号和6号原子）形成新的键就相对容易。专门与后面两个碳原子（环上的3号和5号）形成化学键还不能精确地完成，但如果能做到这一点，就可以制造出许多新的分子。这个项目将测试一些令人兴奋的新想法，即如何只在3号和5号位点（所谓的元位置）的碳上添加原子，从而开辟化学合成的新领域。

Research in chemistry is evolving fast and, as a result, chemistry now addresses important questions in other traditional scientific areas such as biology by looking at problems from the point of view of how molecules behave. It has long been known that many biologically important molecules such as amino acids and proteins have preferred arrangements of their atoms, a phenomenon known as homochirality . Chirality in a molecule means that a reflection of the molecule in a mirror results in another molecule that cannot fit exactly over the starting molecule, just as your right and left hands do not exactly match. The clear preference for particular chiral forms in biological molecules has puzzled scientists for a long time because the normal ways of making these molecules should produce equal amounts of the different chiral forms, giving no overall natural preference for one or another. Some suggestions have been made for reasons for the natural homochirality, but there are weaknesses in the arguments that have stopped them being developed into convincing theories. In the first of the projects described in this proposal, a new way to form a naturally chiral molecule is suggested, which involves connecting together a number of small molecules (of the type that might have been present before life evolved on Earth) to form larger molecules called polymers. If the polymers can then act as a scaffold on which other small molecules join together in the same way, extra copies of these chiral polymers will be made more quickly than other molecules with different chiral properties.The second project will develop a miniature NMR spectrometer the size of a matchbox. NMR is a very powerful technique in chemistry that allows the shapes and structures of molecules to be measured. In medicine it is widely used in MRI scanners to take images of the organs in the body. Most NMR machines are large (bigger than a person), heavy and very expensive because they need big magnets to work well. In this project, a much smaller NMR machine will be built that uses wireless technology to send a signal to a computer. It will be considerably cheaper than normal NMR machines, and much more convenient to pick up and use as a standard piece of equipment in chemistry labs, industrial research labs and manufacturing plants, and medical labs.The third project focuses on an area at the heart of chemistry, which is to develop new ways to make new, interesting and important molecules (known as chemical or molecular synthesis). Benzene rings (six carbon atoms joined in a hexagon) occur in many molecules and chemists would like to be able to control the ways in which new bonds are formed to the different carbon atoms in a benzene ring. If, for example, carbon number 1 at the top of the hexagon is already bonded to another atom such as oxygen, it is relatively easy to make new bonds to the carbon atoms next to it (atoms number 2 and 6 in the ring). Making bonds specifically to the next two carbon atoms (numbers 3 and 5 round the ring) cannot yet be done in a precise way, but if this could be done many new molecules could be made. This project will test some exciting new ideas about how to add atoms only to the carbons at sites 3 and 5 (so-called meta positions) and thus open up new areas of chemical synthesis.