IUPAC nomenclature general

The IUPAC nomenclature system recognizes that most of the common (commercial) polymers have source-based or semisystematic names that are well established by usage. IPUAC does not intend that such names be supplanted by the IUPAC names but anticipates that such names will be kept to a minimum. The IUPAC system is generally used for all except the common polymers. The IUPAC names for various of the common polymers are indicated below the more established source or semisystematic name in the following ... 

This chapter presents a concise overview of the present conventions in coordination nomenclature. Generally, the IUPAC rules and recommendations have been followed. For the cases where the IUPAC practices seemed to be out of date or incomplete, the author has drawn upon the vast expertise in nomenclature available at Chemical Abstracts Service. Sections 3.2.3 and 3.4 deal with ligand locant notation and the numbering of polynuclear complexes may be considered provisional. These concepts are still under active consideration in the various national and international nomenclature commissions and committees. The presentation is relatively brief, but it is hoped that the nomenclature principles are evident, especially when examples presented are closely... 

The IUPAC rules are not the only nomenclature system in use today. Chemical Abstracts Service surveys all the world s leading scientific journals that publish papers relating to chemistry and publishes brief abstracts of those papers. The publication Chemical Abstracts and its indexes are absolutely essential to the practice of chemistry. For many years Chemical Abstracts nomenclature was very similar to IUPAC nomenclature, but the tremendous explosion of chemical knowledge has required Chemical Abstracts to modify its nomenclature so that its indexes are better adapted to computerized searching. This means that whenever feasible, a compound has a single Chemical Abstracts name. Unfortunately, this Chemical Abstracts name may be different from any of the several IUPAC names. In general, it is easier to make the mental connection between a chemical structure and its IUPAC name than its Chemical Abstracts name. 

Names, while following the IUPAC nomenclature, are generally alphabetized by the central atom to facilitate their location. An example of the table organization is given below for A13C4, aluminum tetracarbide. It is entered in Table2.1 as follows ... 

One particular domain in which the alternate method of naming is of significance is that of natural products (perhaps, because of the occurrence of many ring assemblages). Note that this is a domain which, because of the complexity of the IUPAC nomenclature, has opted to formulate its own set of parochial rules of nomenclature, in much the same way as the organic chemistry community formulated IUPAC nomenclature to include 35 "basis" aromatic compounds on which all other "comparable" compounds were to be named [18], This is in contradistinction to various systematic approach, such as a geometry-based proposals for the fusion of benzene modules [19] and for general arenes [20],... 

We have been using the common nomenclature of ethers, which is sometimes called the alkyl alkyl ether system. The IUPAC system, generally used with more complicated ethers, is sometimes called the alkoxy alkane system. Common names are almost always used for simple ethers. 

Other entries in the following sources can also be used in their unabbreviated or acronym forms, botti in the text and in formulae instead of exphcitly drawn structures List of Radical Names in lUPAC Nomenclature of Organic Chemistry, 1979 Edition, Pergamon Press, Oxford, 1979, p. 305-322 (http //www.acdlabs.com/iupac/ nomenclature/79/r79 1036.htm) Acronyms and abbreviations in the general section of lUPAC Gold Book (htQ) // goldbook.iupac.org/list s.html). 

IUPAC nomenclature is generally followed . The cyclic structures are called heterometallacycles and dimetallacycles. When the ring is composed of a metal, a nonmetal, and a carbon, the rings are numbered in that order. When two metals are present, the higher atomic number metal takes precedence. Metallacyclic three-rings which contain a double bond may possess cyclopropenyl cation-like aromaticity and such structures have been proposed <84AG(E)89>. 

As we cover new functional groups in later chapters, the applicable IUPAC rules of nomenclature will be given. In addition, Appendix A at the back of this book gives an overall view of organic nomenclature and shows how compounds that contain more than one functional group are named. For the present, let s see how to name branched-chain alkanes and learn some general naming rules that are applicable to all compounds. 

Alkanes are a class of saturated hydrocarbons with the general formula C H2n. -2- They contain no functional groups, are relatively inert, and can be either straight-chain (normal) or branched. Alkanes are named by a series of IUPAC rules of nomenclature. Compounds that have the same chemical formula but different structures are called isomers. More specifically, compounds such as butane and isobutane, which differ in their connections between atoms, are called constitutional isomers. 

Currie LA (1995), IUPAC, Analytical Chemistry Division, Commission on General Aspects of Analytical Chemistry. Nomenclature in evaluation of analytical methods including detection and quantification capabilities. Pure Appl Chem 67 1699... 

Before proceeding one needs to mention Chemical Abstracts (CA), a journal published by the American Chemical Society, that abstracts the world s chemical hterature and has developed its own nomenclature rules. The CA rules are generally very close to the IUPAC rules, but there are some differences. Most of the differences are not important at the level of the discussions in this book. One difference that needs to be mentioned is the placement of locants. CA does not place locants immediately before the part of the name to which they apply. Thus, the CA name for the first subunit in XV is 2,4-pyridinediyl instead of pyridine-... 

The general formula for boric acid esters is B(OR)3. The lower molecular weight esters such as methyl, ethyl, and phenyl are most commonly referred to as methyl borate [121 -43-7], ethyl borate [150-46-9], and phenyl borate [1095-03-0], respectively. Some of the most common boric acid esters used in industrial applications are Us ted in Table 1. The nomenclature in the boric acid ester series can be confusing. The IUPAC committee on boron chemistry has suggested using thalkoxy- and triaryloxyboranes (5) for compounds usually referred to as boric acid esters, trialkyl (or aryl) borates, trialkyl (or aryl) orthoborates, alkyl (or aryl) borates, alkyl (or aryl) orthoborates, and in the older literature as boron alkoxides and aryloxides. Cyclic boric acid esters, which are trimeric derivatives of metaboric acid (HB02), are known as boroxines (1). 

Another type of anion, confined for practical purposes to boron compounds, has no unshared electrons at the anionic site, and must be thought of as being formed by addition of hydride to a boron atom (or other atom with an incomplete valence shell). Such structures were not anticipated at the time general heterocyclic nomenclature was developed, and they are only recently being fitted into systematic nomenclature (IUPAC Provisional Recommendation 83.2). Proposals for a suffix to indicate such structures are under consideration (1982). 

The most recent recommendations by IUPAC for naming heterocyclic skeletons include only a small number of basic nomenclature systems, and, as a consequence of its need to provide unique names, the number of systems employed by Chemical Abstracts is even smaller. Of the systems now to be outlined, most are described in detail in the Appendix (to which reference is made where appropriate) the following text will cover only the general principles involved. Many of the systems are modifications of those used for carbocycles. 

The application of replacement nomenclature has already been discussed (Section II, B, 1, b) and will not be dealt with further here (although replacement names will be given where appropriate). Also it is unnecessary to discuss the use of the trivial names allowed by IUPAC they may be applied whenever it appears appropriate. Those cases in which ring assembly nomenclature should be used are generally obvious and require no comment. Problems do arise, however, in deciding whether to use fusion nomenclature or von Baeyer nomenclature. 

A comprehensive treatment of the nomenclature of substituted heterocycles will not be given here. This section will deal only with the general principles involved and with a few specific topics. For a detailed exposition, the reader should consult the IUPAC Organic Nomenclature Rules, Section C.6... 

Heterocyclic systems can be named by various methods, depending on ring size, the presence or absence of metal atoms, the availability of trivial names, etc. For this index the naming of the heterocyclic parents has generally followed the practices of IUPAC and Chemical Abstracts. Thus Hantzsch-Widman names have been employed for all monocyclic systems and for the other systems when the smallest ring size is five atoms or more, but replacement nomenclature has usually been followed for bicyclic and higher systems when they contain three- and four-membered rings. 

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