Notation Wiswesser

In Sections 2,.3.1-2.3.4, only the four most popular line notations, Wiswesser (WLN), ROSDAL. SMILES, and Sybyl (SEN), arc discussed. Whereas WLN is now almost obsolete, SMILES is quite an important representation and is widely used (Figure 2-7). 

An alternative way to represent molecules is to use a linear notation. A linear notation uses alphanumeric characters to code the molecular structure. These have the advantage of being much more compact than the connection table and so can be particularly useful for transmif-ting information about large numbers of molecules. The most famous of the early line notations is the Wiswesser line notation [Wiswesser 1954] the-SMILES notation is a more recent example that is increasingly popular [Weininger 1988]. To construct the Wiswesser... 

Wiswesser line notation The Wiswesser line-formula notation (WLN) is a method for expressing the more usual graphical structure of a chemical compound as a linear string of symbols. The resulting alternative notation is unambiguous, short and particularly suitable for computer processing and retrieval but can also be understood easily by chemists after minimal training in its use. 

WLN Wiswesser line notation, wolfram An alternative name for tungsten. 

The Wiswesser Line Notation (WLN) was introduced in 1946, in order to organize and to systematically describe the cornucopia of compounds in a more concise manner. A line notation represents a chemical structure by an alphanumeric sequence, which significantly simplifies the processing by the computer [9-11], (n many cases the WLN uses the standard symbols for the chemical elements. Additionally, functional groups, ring systems, positions of ring substituents, and posi-... 

W.J. Wiswesser, A Line-Formula Chemical Notation, Y. Thomas Crowell, New York, 1954. 

W. J. SUis esseT,AEine-Formula Chemical Notation, Thomas Y. CroweU Co., New York, 1954. E. G. Smith and P. A. Baker, The Wiswesser Eine-Formula Chemical Notation (lELiV), 3rd ed.. Chemical Information Management, Inc. (CIMI), Cherry Hill, N.J., 1975. 

The above is based on the calculation of a collective r for the whole molecule. This value changes the HOMO of either the diene or dienophile, as is necessary. This equation is accurate to about 0.5 eV on either side of the known values [15]. The value of ttotal is inserted into the HOMO-LUMO calculation as the parameter r Y), Note that in its pure form, this equation only yields values for the HOMO orbitals. Corrections are used for the calculation of the LUMO values. Table 1 contains examples of the Wiswesser Line Notation and the raw r values used in the computation of orbital energies. 

Smith, Elbert G., ed.. The Wiswesser Line - Formula Chemical Notation, McGraw-Hill, New York, 1968. 

Fritts, Lois E., Margaret Mary Schwind, Using the Wiswesser Line Notation (WLN) for Online, Interactive Searching of Chemical Structures, J. Chem. Inf. Comput. Sci., 22, (1982), pp. 106-109. 

Smith, E. Baker, P. The Wiswesser Line-Formula Chemical Notation (WLN)" 3rd Ed., CIMI, New Jersey, 1975. 

Figure 4. Representation using Wiswesser line notation...

Eakin [13] describes the chemical structure information system at Imperial Chemical Industries Ltd., where registration is based on Wiswesser Line Notation. For connection tables, the unique, unambiguous representation is derived automatically, i.e., a single, invariant numbering of the connection table is algorithmically derived. 

Programs now exist to convert Wiswesser Line Notation [29], Hayward [30], and IUPAC [18] linear notations to connection tables. Because fragment codes alone do not provide the complete description of all structural detail, conversion to other representations is typically not possible. 

Hyde, E., F. W. Matthews, Lucille H. Thompson, and W. J. Wiswesser, "Conversion of Wiswesser Notation to a Connectivity Matrix for Organic Compounds," Journal of Chemical Documentation, 7(4), 200-203 (1967). 

Ebe, Tommy, and Antonio Zamora, "PATHFINDER II, A Computer Program That Generates Wiswesser Line Notations for Polycyclic Structures," Journal of Chemical Information and Computer Sciences, 16( 1), 36-39 (1976). 

A Chemically Oriented Information Storage and Retrieval System II. Computer Generation of the Wiswesser Notation of Complex Polycyclic Structures," Journal of Chemical Documentation, (3), 133-138 (1968). 

This column gives the name and, below it, the Wiswesser Line Notation (WIN) designation of each compound included. Some of the names are the simplest and shortest trivial names for the compounds they denote others follow Chemical Abstracts nomenclature. The WLN designation is given only once for each compound when an entry continues onto the following pair of pages the name of the compound is repeated but the WIN designation is not. 

Atlas of Spectral Data and Physical Constants for Organic Compounds (1975), 2nd edn. Eds J. G. Grassell and W. M. Ritchey. Cleveland, Ohio CRC Press. Six volumes containing the following data on 21 000 compounds Wiswesser Line Notation, i.r., u.v., lH and l3C n.m.r. and m.s. data. 

Wiswesser Line Formula Chemical Notation Number of EMIC references Teratogenic data availability Mutagenic data availability Carcinogenic data availability Environmental occurrence Toxicity data availability Chemical information availability Chemical fragment names... 

The Pesticide Index (ref. 14) lists the following categories of pesticides acaricides, attractants, chemosterilants, defoliants, fungicides, herbicides, insecticides, molluscicides, nematicides, plant regulators, repellents, and rodenticides. Listings are in alphabetical order with structural and molecular formulae for single chemical entities. Other data include CAS nomenclature and number Wiswesser Line Notation LD-50 and test animal data when available physical appearance and safety information. Also provided are a CAS nomenclature index separate molecular (line) formulae of chemicals identified by their common names a separate section of Wiswesser line notations, also with common names an appendix of manufacturers, and an appendix of recent publications dealing with pesticide names. 

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