X-RAY CRYSTALLOGRAPHY
X-RAY CRYSTALLOGRAPHY
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DOI：
10.1038/scientificamerican0768-58
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发表时间：
1968-01-01
影响因子：
3
通讯作者：
BRAGG, L
中科院分区：
文献类型：
--
作者：
BRAGG, L
五十六年前，随着德国的马克斯·冯·劳厄发现一束X射线可以被晶体中排列有序的原子有序地衍射或散射，一门新的分支科学诞生了。起初，人们对冯·劳厄的阐述主要关注的是它与X射线性质争论的关系;它证明了X射线是波而不是粒子。然而，我们中的一些人很快就明白了，这种效应开辟了一种研究物质的新方法，事实上，人类已经拥有了一种新形式的显微镜，比任何光学显微镜都强大几千倍，原则上可以重新解决物质的结构，直到原子尺度。自1912年以来，X射线晶体学的发展已经超过了我们早期的预期。它不仅揭示了原子在许多不同形式的物质中的排列方式，而且使人们对原子间力的性质和物质的大尺度性质有了大量的了解。在许多情况下，这种新知识导致了对其他科学分支的思想的根本性修正。在过去的几年里，随着对生命物质的几种基本分子--蛋白质--的结构分析的成功，X射线晶体学达到了一个高潮。蛋白质中的每一个分子都由成千上万个原子通过一个令人难以置信的复杂的化学键网络连接在一起。本文的目的是追溯过去半个多世纪以来X射线晶体学的发展历程，并对其进行概括性的总结。在这样做的时候，我将试图回答两个关键问题：为什么是X射线？为什么是水晶？X射线晶体学是一门奇特的分支科学。持续多年的调查结果可能是
Fifty-six years ago a new branch of science was born with the discov ery by Max von Laue of Germany that a beam of X rays could be diffracted, or scattered, in an orderly way by the orderly array of atoms in a crystal. At first the main interest in von Laue's dis covery was focused on its bearing on the controversy about the nature of X rays; it proved that they were waves and not particles. It soon became clear to some of us, however, that this effect opened up a new way of studying matter, that in fact man had been presented with a new form of microscope, several thou sand times more powerful than any light microscope, that could in principle re solve the structure of matter right down to the atomic scale. The development of X-ray crystallography since 1912 has more than fulfilled our early expecta tions. It not only has revealed the way atoms are arranged in many diverse forms of matter but also has cast a flood of light on the nature of the forces be tween the atoms and on the large-scale properties of matter. In many cases this new knowledge has led to a fundamental revision of ideas in other branches of sci ence. A culmination of sorts has been reached in the past few years with the successful structural analysis of several of the basic molecules of living matter the proteins-each of which consists of thousands of atoms held together by an incredibly intricate network of chemical bonds.The purpose of this article is to go back to the beginning and broadly sum marize the course of X-ray crystallog raphy over the past half-century or so. In so doing I shall try to answer two key questions: Why X rays? Why crystals? X-ray crystallography is a strange branch of science. The result of an in vestigation lasting many years can be