Cambridge Data Base

Table B.l. Short format references to Cambridge Data Base entries cited in this book REFCODE Journal, volume, page, year...

Fragment search in the Cambridge Crystallographic Data Base reveals 127 hits out of 42381 entries (state May 1985) having dimethyl sulfoxide as the search query and allowing for the presence of metal atoms. In absence of such elements, the number of hits is reduced to 27. 

The collection of these data bases include five that are available exclusively from Cambridge Scientific Abstracts (CSA) Pollution Abstracts, Toxicology Abstracts, Ecology Abstracts, Health and Safety Science Abstracts, and Aquatic Pollution and... 

POLTOX also contains two other useful data bases Toxline (described earlier) and the Food Science and Technology Abstracts (FSTA) libraries. The FSTA component is a reasonably comprehensive collection of information regarding toxicological aspects of compounds found in food, including contamination, poison, and carcinogenic properties. The CD-ROM product is available from Compact Cambridge, 7200 Wisconsin Avenue, Bethesda, MD 20814. 

Figure 2. Schematic diagram of the hydrogen-bond structure in the crystal structure of gentiobiose (GENTOSOl REFCODE in Cambridge Crystallographic Data Base). The arrows indicate infinite chains. Distances are H—O in A, angles are 0-H—O in degrees. The covalent 0-H bond lengths have been normalized to 0.97 A.

In the first phase, a data base is acquired from one of a variety of sources. Some of the CIS data bases have been developed specifically for the CIS, an example of this being the mass spectral data base (2). Others, such as the Cambridge Crystal File (4), are leased for use in the CIS and still others, such as the X-ray powder diffraction file (5), are operated within the CIS by their owners, in this case the )oint Committee on Powder Diffraction Standards. 

Molecular structure data bases are particularly useful in the analysis and engineering of zinc coordination polyhedra, and statistical results from the Brookhaven Protein Data Bank (Bernstein et al., 1977) and the Cambridge Structural Database (Allen et al., 1983) are presented... 

The comparison can be made manually on the basis of collections of tables (for example, A. Cornu R. Massot Compilation of Mass Spectral Data) or may be effected with computer assistance large databases can be used (e.g. Mass Spectral Data Base, Royal Society of Chemistry, Cambridge). 

Recent research on the Cambridge structural data base shows139 11 alkenes (and 2 alkynes) which are involved in interactions with the —OH group, with distance H- C of olefin <2.4 A. 66 is an instance of intramolecular hydrogen bonding interactions140. Intermolecular hydrogen bonds can be observed in 67141 and 68142. 

The text has been substantially revised, many new examples incorporated and errors corrected. A substantial new chapter dealing with supramolecular chemistry has been incorporated. Once again, a deliberate decision was made to try to limit references to the secondary rather than the primary literature. Where structural data have been presented, the use of the files of the Cambridge Crystallographic Data Centre and the Brookhaven Protein Structure Data Base are gratefully acknowledged. 

Cambridge Structural Data Base (CSD). Cambridge Crystallographic Data Centre, University Chemical Laboratory, Cambridge, England. 

Kovari, Z., Bocskei, Zs., Kassai, Cs., Fogassy, E., and Kozma, D. Investigation of the structural background of stereo- and enantioselectivity of 0,0 -dibenzoyl-(2/ ,3R)-tartaric acid-alcohol supramolecular compound formation, Chirality 2003, submitted for publication. Crystal data are deposited at the Cambridge Crystal Structure Data Base under the following numbers CCDC 181497, 181498, 181499,181500, 181501, 181502, 181503, 181504,181505. 

Experimental structures are often the basis for computational studies they are used as input structures for structure optimizations and conformational searches, for the parameterization and validation of force fields and for analyzing the effects of crystal lattices. More than 200,000 experimental structures have been reported, and the majority are found in the Cambridge Structural Data Base (CSD, small molecular structures which include carbon atoms) the Inorganic Crystals Structure Database (ICSD) and the Protein Data Base (PDB this database includes X-ray as well as optimized structures based on NMR data). 

A simultaneously performed search in the Cambridge Structural Data Base revealed that expanded X-C-C bond angles are more or less common (see Table 1) [13-15]. 

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... 

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