Significance of Small Molecule Crystal Structural Studies

4 Significance of Small Molecule Crystal Structural Studies 

These advances have made X-ray and neutron single crystal analysis the principal methods for exploring and mapping the nanometer world of interatomic interactions for the past decade. It is a world where the nanometer, 10 A, has the same place as the meter in the macroscopic world of everyday life. It is a striking observation that the level of understanding of biological structure and function has, over the past three decades, been directly proportional to the level of crystallinity 

The crystallographic data explosion. A consequence of the development of the direct methods of crystal structure analysis combined with automation of the experimental measurements has been the dramatic increase in the number of crystal structure analyses reported, as illustrated in Fig. 1.6. Fortunately, this explosion in crystallographic data has been accompanied by the development of data bases where this vast amount of structural information at atomic resolution is stored. Equally important has been the computer software development, whereby this information can be retrieved in forms appropriate to the interests of the interrogators of the data bases [39, 40]. 

As shown in Fig. 1.7, with the protein structures excepted, there has not been a correspondingly large increase in the complexity of the structures analyzed. This is because of the increased difficulty in growing single crystals of adequate size as 

Since this structural data consists of atomic parameters which describe the interatomic vectors in three dimensions, the simultaneous evolvement of computer graphics has played an important role in the way the data can be used. The data base which is the particular source for the hydrogen bond data analyzed in this monograph is the Cambridge Crystallographic Structure Data Base [39, 40]. There is also a vast amount of structural information in the protein and nucleic acid data 

---