Nomenclature name

Substitutive lUPAC nomenclature names epoxides as epoxy derivatives of alkanes According to this system ethylene oxide becomes epoxyethane and propylene oxide becomes 1 2 epoxypropane The prefix epoxy always immediately precedes the alkane ending it is not listed m alphabetical order like other substituents... 

Halogen Derivatives. Using substitutive nomenclature, names are formed by adding prefixes listed in Table 1.8 to the name of the parent compound. The prefix perhalo- implies the replacement of all hydrogen atoms by the particular halogen atoms. 

Benennung, /, nomenclature name, naming, title, denomination, term,... 

The most frequently used systematic nomenclature names the fatty acid after the hydrocarbon with the same number and arrangement of carbon atoms, with -oic being substituted for the final -e (Genevan system). Thus, saturated acids end in -anoic, eg, octanoic acid, and unsaturated acids with double bonds end in -enoic, eg, octadecenoic acid (oleic acid). 

The systematic naming of substances and presentation of formulae involve the construction of names and formulae from units that are manipulated in accordance with defined procedures in order to provide information on composition and structure. There are a number of accepted systems for this, of which the principal ones will be discussed below. Whatever the pattern of nomenclature, names and formulae are constructed from units that fall into the following classes ... 

Specialists in nomenclature recognise two different categories of nomenclature. Names that are arbitrary (including the names of the elements, such as sodium and hydrogen) as well as laboratory shorthand names (such as diphos and LithAl) are termed trivial names. This is not a pejorative or dismissive term. Trivial nomenclature contrasts with systematic nomenclature, which is an assembly of rules, themselves arbitrary. The function of specialists in nomenclature is to codify such rules so that everyone can use them to identify pure substances, rather like many of us use an alphabet to represent words. There may be more than one way to name a compound or species, and no one way may be superior to all the others. Names also vary in complexity, depending upon how much information needs to be conveyed. For example, a compositional name conveys less information than a structural (or constitutional) name, because this includes information about the arrangement of atoms in space. 

Two older systems of nomenclature name aliphatic azo compounds diazenes or diimines, as in structure VII. 

Anions. The hydrogen nomenclature name described above consists of two parts, the second of which is an anion name. This can stand alone to represent the anion itself. 

Table I is a list of all the enzymes that will be mentioned in this article. Neither the E.C. number nor the nomenclature name is convenient for repeated use in a discussion. Therefore, for the running text, we shall use mostly the time-established trivial names. We shall use 1 to 3-letter symbols in the Tables. For these, we have followed common practice as much as possible, but we had to innovate in some cases in order to avoid confusion.

IUPAC nomenclature names ethers as alkoxy alkanes, alkoxy alkenes, or alkoxy alkynes. The group in the chain that has the greatest number of carbon atoms is designated the parent compound. In the case of aromatic ethers, the benzene ring is the parent compound. 

Furthermore, the use of special subgroup names such as fenchenes, which applies to a series of synthetic compounds to indicate their derivation from fenchyl and iso-fenchyl derivatives and reportedly (33) to distinguish them from closely related naturally occurring terpenes, obviously complicates the problem of systematizing nomenclature. Names such as cyclofenchene and /8-difenchene are two additional memory exercises. Such irregularities in nomenclature have, of course, been carried over into the nomenclature of derivatives of these bicyclic hydrocarbons. 

Full-featured structure drawing and presentation program. Supports IUPAC nomenclature (names to structures, structures to names). Integrated with CBIS. Supports personal databases of structures, reactions, and graphics. 

Fig. 15 A molecule having two equally acceptable nodal nomenclature names, rather than a single canonical name.

In other words, the nomenclature describes the relevant physics and one need not be concerned with the nature of the orbitals (tc ). On the other hand, had this been merely a transition state that is followed by a rearrangement to form a skew rhombus with traditional single bonds, this would also be reflected in the nomenclature namely the final product would then be nomenclated as ... 

Systematic names or nomenclature names (e.g., International Union of Pure and Applied Chemistry [IUPAC])... 

IUPAC-like expressions, true IUPAC nomenclature names, and InChl and SMILES representations of chemical compounds are well suited for detection by machine learning approaches. Conditional random fields (CRFs)41 and support vector machines have been used for the detection of IUPAC expressions in scientific literature 42 Other approaches are based on rules sets43 44 or combinations of machine learning with rule-based approaches 45 All these approaches have in common that they face one significant problem the name-to-structure problem. 

The three-dimensional structure is the most unique description of a chemical compound. That is why chemical entities should be compared on the basis of their structure as represented in a connection table, not on their common or nomenclature name. Comparison of structures, however, requires that mentions of chemical entities in text are translated into connection tables this is typically done by name-to-structure (N2S) tools. On a conference on chemical information in Sitges (International Chemistry Information Conference [ICIC]) 2007), preliminary data on attempts at benchmarking N2S tools were reported 46 Although this analysis is preliminary and care should be taken to avoid drawing conclusions that are not supported by the analysis, these data suggest that the N2S tools currently available are correctly converting only between 30% and 50% of all named entities. 

Recognition of chemical nomenclature names (rule-based approach for the recognition of chemical fragment strings)... 

Alloy phases will be described sfructurally using the following multiple (and somewhat redundant) nomenclature Name(s) Prototype (Pearson Symbol, Stmcture Report Symbol). As an example CuZn ( 8-Cu-Zn, /3-brass) CsCl (cP2, B2) type. (Note The Pearson symbol already contains the crystal system and Bravais lattice). Alloy phase compilations with stmctural data are available. 

Amino acids exist in nature as only one of these enantiomers. Except when the R group is CH2SH, the stereogenic center on the a carbon has the S configuration. An older system of nomenclature names the naturally occurring enantiomer of an amino acid as the L isomer, and its unnatural enantiomer the D isomer. 

In an/ science there are two basic requirements — classification and nomenclature (names) ... 

Whatever the pattern of nomenclature, names are constructed from entities such as ... 

These names are easy for us to remember because we come into contact with these compounds often. However, as the number of compounds increased, organic chemists realized that historical names were not adequate because they revealed nothing about the structure of a compotmd. Thousands of such compounds and their common names had to be memorized What was needed was a set of nomenclature (naming) rules that would produce a unique name for every organic compound. Furthermore, the name should be so descriptive that, by knowing the name, a student or scientist could write the structure. 

The stereochemistry of side-chain substituents is described by the sequence rule procedure, where any chiral centers formed by substituents at C-20 or above are assigned the (R) or (S) configuration. This designation, when employed, precedes the entire nomenclature name (see Section 3.5.2.2). For brevity, the side-chain stereochemistry will not be described in further detail. 

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