Names, trivial

These trivial names may be used for the unsubstituted hydrocarbon only  

Table 1.5 Trivial Names of Heterocyclic Systems Suitable for Use in Fusion

Table 1.6 Trivial Names for Heterocyclic Systems That Are Not Recommended

Colan The trivial name given to di-phenylethyne (diphenyl acetylene), CflHs C = C CeHs- Obtained as volatile colourless crystals, m.p. 6TC, by HgO oxidation of benzil bis-hydrazone. 

TABLE 1.5 Trivial Names of Heterocyclic Systems Suitable for Use in Fusion Names Listed in order of increasing priority as senior ring system. 

Recognized trivial names for composite radicals are used if they lead to simplifications in naming. Examples are 

Tablel.10 Retained Trivial Names of Alcohols and Phenols with Structures 1.24

Neville-Wintber acid The trivial name given to 4-hydroxy-1-naphthalene sulphonic acid. 

In the example of Figure 2-5, the compound has the trivial name phenylalanine but the lUPAC name is 2-amino-3-phenylpropanoic acid, which indicates a carbon 

Eulvene, for methylenecyclopentadiene, and stilbene, for 1,2-diphenylethylene, are trivial names that are retained. 

The systematic lUPAC nomenclature of compounds tries to characterize compounds by a unique name. The names are quite often not as compact as the trivial names, which are short and simple to memorize. In fact, the lUPAC name can be quite long and cumbersome. This is one reason why trivial names are still heavily used today. The basic aim of the lUPAC nomenclature is to describe particular parts of the structure (fi agments) in a systematic manner, with special expressions from a vocabulary of terms. Therefore, the systematic nomenclature can be, and is, used in database systems such as the Chemical Abstracts Service (see Section 5.4) as index for chemical structures. However, this notation does not directly allow the extraction of additional information about the molecule, such as bond orders or molecular weight. 

Monocyclic Aromatic Compounds. Except for six retained names, all monocyclic substituted aromatic hydrocarbons are named systematically as derivatives of benzene. Moreover, if the substituent introduced into a compound with a retained trivial name is identical with one already present in that compound, the compound is named as a derivative of benzene. These names are retained  

Enzymes are classified in terms of the reactions which they catalyse and were formerly named by adding the suffix ase to the substrate or to the process of the reaction. In order to clarify the confusing nomenclature a system has been developed by the International Union of Biochemistry and the International Union of Pure and Applied Chemistry (see Enzyme Nomenclature , Elsevier, 1973). The enzymes are classified into divisions based on the type of reaction catalysed and the particular substrate. The suffix ase is retained and recommended trivial names and systematic names for classification are usually given when quoting a particular enzyme. Any one particular enzyme has a specific code number based upon the new classification. 

In 1814, J.J. Berzelius succeeded for the first time in systematically naming chemical substances by building on the results of quantitative analyses and on the definition of the term "element by Lavoisier. In the 19th century, the number of known chemical compounds increased so rapidly that it became essential to classify them, to avoid a complete chaos of trivial names (see Section 2.2.4). 

The problem of perception complete structures is related to the problem of their representation, for which the basic requirements are to represent as much as possible the functionality of the structure, to be unique, and to allow the restoration of the structure. Various approaches have been devised to this end. They comprise the use of molecular formulas, molecular weights, trade and/or trivial names, various line notations, registry numbers, constitutional diagrams 2D representations), atom coordinates (2D or 3D representations), topological indices, hash codes, and others (see Chapter 2). 

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