Structure databases literature

With the increasing number of publications on block copolymer micelles (a database literature search with these three associated keywords already gives more than 500 references), an exhaustive description of all previous works would not be possible in the framework of the present review. This contribution has rather as its purpose giving a general overview about block copolymer micelles for the nonspecialist and will therefore try to answer such practical questions as how does one prepare block copolymer micelles How does one characterize them What are the different types of structures that can be formed How can we predict them How does one tune the morphology of these micelles These basic questions and the corresponding answers will be illustrated by selected examples. Then, we will focus on the new directions that are currently implemented in this field. 

SIS s Toxicology and Environmental Health Information Program (TEHIP) produces TOXNET (TOXNET 2007), a collection of toxicology and environmental health databases that includes, among others, the Hazardous Substances Data Bank (HSDB), a database of potentially hazardous chemicals, TOXLINE (containing references to the world s toxicology literature), and ChemIDplus (a chemical dictionary and structure database). 

The basis for the collection of the literature of this chapter was an inquiry in Chemical Abstracts (CA) and the Cambridge Structural Database (CSD) , August 2002. 

Each compound mentioned in this book is followed by its collection code (number) in the Inorganic Crystal Structure Database (Bergerhoff et al. 1983) or its refcode (letters) in the Cambridge Crystallographic Database (Allen et al. 1979). A reference to the original paper describing the structure of the compound is listed under this code in the literature references in Appendix 5. 

GlycosidlQ www.glycosuite.com Joshi et al. (22) Matches MS data to a theoretical fragmentation of a database of reported glycan structures in literature. Not open access and requires subscription. 

ChemSpider currently searches over 14 million compounds in multiple chemical structure databases. These include databases of curated literature data, chemical vendor catalogs, molecular properties, enviromnental data, toxicity data, analytical data, and so on. ChemSpider intends to aggregate into a single database all chemical structures available within open access and commercial databases and to provide the necessary pointers from the ChemSpider search engine to the information of interest. This service will allow users to either access the data immediately via open-access links or have the information necessary to continue their searches into commercially available systems. 

Structure registration is the process of entering structural information in a centralized repository, usually a structure database. These repositories serve as a pool for providing structure information that has been created in other departments of a company. Structure databases are set up according to the individual needs of a department or company. They consist of a common representation of a structure in a standardized file format, such as MolFile, SDF, reaction (RXN) (MDL), JCAMP (International Union of Pure and Applied Chemistry), or simplified molecular input line entry specification. Any additional data can be stored with the structure depending on the context typical examples are structure properties, reaction conditions, and literature references. 

A number of statistical analyses of the literature have been carried out in an attempt to estimate the extent of polymorphism. A search of the Cambridge Structural Database on the keywords polymorph , form , modification and phase indicates that about 3.5% of the -350 000 entries fall into this category. Approximately 25 % of the entries are either solvates or hydrates. At the other end of the spectrum, Byrn has reported that of the >150 compounds submitted for crystal form screening and analysis to SSCI, Inc. 85 % exhibit more than one crystal form, 37% are solvates and 31 % are hydrates [40]. Other studies based on different selection criteria reveal results falling somewhere between these two extremes [41]. For instance, Griesser and Burger have collected information on about 600 polymorphic forms and solvates (including hydrates) pharmaceutical compounds that are solid at 25 °C [41c],... 

Ihe literature search ol X-ray crystal diffraction data was conducted In means of the Cambridge Structural Database t l[Pg.299]

Many surfaces exhibit a different periodicity than expected from the bulk lattice, as is most readily seen in the diffraction patterns of LEED often additional diffraction features appear which are indicative of a superlattice. This corresponds to the formation of a new two-dimensional lattice on the surface, usually with some simple relationship to the expected ideal lattice [5]. For instance, a layer of adsorbate atoms may occupy only every other equivalent adsorption site on the surface, in both surface dimensions. Such a lattice can be labelled (2x2) in each surface dimension the repeat distance is doubled relative to the ideal substrate. In this example, the unit cell of the original bulk-like surface is magnified by a factor of two in both directions, so that the new surface unit cell has dimensions (2 x 2) relative to the original unit cell. For instance, an oxygen overlayer on Pt (111), at a quarter-monolayer coverage, is observed to adopt an ordered (2 X 2) superlattice this can be denoted as Pt (111) -i- (2 x 2)-0, which provides a compact description of the main crystallographic characteristics of this surface. This particular notation is that of the Surface Structure Database [141 other equivalent notations are also common in the literature, such as Pt (111)-(2 x 2)-0 or Pt... 

Discussion is restricted to N- and 0-donor ligands for reasons of space. Finally, discussion will concentrate on cage eompounds containing six or more metal centers. Literature searching has predominantly used the Cambridge Structural Database. Some examples will have been missed ... 

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