Names of compounds

A compound can be identified either by its formula (e.g., NaCl) or by its name (sodium chloride). In this section, you will learn the rules used to name ionic and simple molecular compounds. To start with, it will be helpful to show how individual ions within ionic compounds are named. 

Click Coached Problems for a self-study module on polyatomic ions. 

Nearly all cations are monatomic the majority of anions are polyatomic. 

To name a compound, you have to decide whether it is molecular or ionic the rules are different 

Monatomic cations take the name of the metal from which they are derived. Examples include 

There is one compHcation. As mentioned earlier, certain metals in the transition and post-transition series form more than one cation, for example, Fe and Fe +. To distinguish between these cations, the charge must be indicated in the name. This is done by putting the charge as a Roman numeral in parentheses after the name of the metal  

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Both common and systematic names of compounds are used throughout this volume, depending on which the Editor-in-Chief felt was more appropriate The Chemical Abstracts indexing name for each title compound, if it differs from the title name, is given as a subtitle Systematic Chemical Abstracts nomenclature, used in both the 9th and 10th Collective Indexes for the title compound and a selection of other compounds mentioned in the procedure, is provided in an appendix at the end of each preparation. Registry numbers, which are useful in computer searching and identification, are also provided in these appendixes. Whenever two names are concurrently in use and one name is the correct Chemical Abstracts name, that name is adopted. For example, both diethyl ether and ethyl ether are normally used. Since ethyl ether is the established Chemical Abstracts name for the 8lh Collective Index, it has been used in this volume The 9th Collective Index name is 1,1 -oxybisethane, which the Editors consider too cumbersome. 

Translate names of compounds the chief function of which is alcoholic (or phenolic) so that the name ends in -ol as, glycerol, resorcinol, mannitol, pinacol (not pinacone). 

Names of compounds m small capital Utters indicate substances for which directions are given the numbers m bold face type refer to volumes of Organic Syntheses, numbers in italics refer to pages in those volumes on which preparative directions are given and num bers in Arabic refer to pages on which the compounds or subjects are mentioned in connection with other preparations For example Acetoacetic Ester 4 45 6, 36 indicates... 

Part I contains entries referring to the names of compounds according to the Chemical Abstracts Systematic Nomenclature (see Index Guide, Chemical Abstracts vol 76, 1972) The systematic name is followed by Chemical Abstracts Registry Number m brackets (see Chemical Abstracts Registry Handbook 1965-71 and Supplements) and page number... 

The index consists of two parts. Part I contains entries referring to the conventional names of compounds as they appear in the preparations of this volume followed by the systematic names in brackets, if the nomenclature differs The bracketed names conform to the systematic nomenclature adopted by the Chemical Abstracts Service starting with Chemical Abstracts Volume 76 (1972) Part II of the index contains entries of the subjects of this volume with compound names in a reversed order of Part I... 

Many compounds were given informal, common names before their compositions were known. Common names include water, salt, sugar, ammonia, and quartz. A systematic name, on the other hand, reveals which dements are present and, in some cases, the arrangement of atoms. The systemic naming of compounds, which is called chemical nomenclature, follows the simple rules described in this section. 

This index is divided into two parts. Part 1 gives the names of compounds as used in these volumes as well as general terms for classes of compounds, types of reactions, synthetic applications, special apparatus, and unfamiliar methods. The complete names of all specific compounds are given in normal order as written in the text (e.g., ethyl cyano-acetate appears under ethyl). Some entries are common names and others are systematic Chemical Abstracts names, whichever was used in the text. 

The chemical name of compounds composed of only two elements usually ends with the suffix ide. The chemical name for water, for example, which is composed of two atoms of hydrogen and one of oxygen, and whose chemical formula is H20, is, therefore, hydrogen oxide. The chemical name for common table salt, composed of one atom of sodium and one of chlorine, and has the formula is NaCI, is sodium chloride. Pyrite, an iron ore composed of one atom of iron (ferrum in Latin) and one of sulfur, has the formula FeS, and its chemical name is ferrous sulfide. 

The name of compounds whose molecules contain three or more elements, usually including oxygen, ends in the suffix ate. Thus the chemical name for limestone, whose chemical formula is CaC03, is calcium carbonate. That of green vitriol, also known as copperas, whose formula is FeS04, is iron sulfate. The names and formulas of some chemical compounds related to archaeological studies are listed in Table 7. 

A further complication that may be encountered in the nomenclature of branched-chain monosaccharides is in the numbering of the carbon atoms of the molecule. There is some precedent for numbering the carbon atoms of the branched moiety continuously with the carbon atoms of the main chain. However, this can result in confusion and ambiguity, especially when there are further substituents on the branched carbon atoms. In this connection, the Geneva system of nomenclature11 provides a reasonable solution, which is illustrated in the naming of compounds XII10 and XIII. 

A standard style is used to assign names of compounds in the tables of density data. These are called Table Names. These names, along with other kinds of names are included in the Chemical Name Index provided at the end of the volume. 

Shown below are the aromatic ring systems and names of compounds in this book used for Method 1. There are two types of these. The ori/zo-fused and the ortho- and peri-fused rings. For each of the ori/zo-fused ring systems the corresponding saturated ring system and the name obtained by Method 2 is shown. 

Method 1 is used for the Table Names of compounds and their derivatives in the list above. Method 2 is used for other fused-ring compounds. Several examples of Method 1 and Method 2 names for the same compounds are ... 

Nomenclature is the term referring to the naming of compounds. In this section, we will investigate how to name inorganic compounds. We will see how to name organic compounds in Chapter 21. In order to name compounds correctly, you will need to memorize certain elements and ions, and you will need to apply a few rules. 

Similarly, well before Lavoisier, in London in the mid-eighteenth century, the Royal College of Physicians convened the Pharmacopoeia Committee, which adopted the principle that names of compounds should be related to their constituents rather than to their observable properties or to analogies with things like butter and flowers. The physicians 1746 dictionary of names influenced Macquer s 1766 dictionary of chemistry. 43... 

If we think about other and later changes in symbols, vocabulary, and imagery, the struggle for invention and control of language, and thereby of theory, is obvious, whether in controversies over atomic symbols (spheres or letters ), molecular formulas (O = 8 or 16 ), functional groups ("radicals" or "residues" ), or names of compounds ("rational" or "empirical" ). 

IUPAC NAMES OF COMPOUNDS INVESTIGATED IN BOTH POSITIVE- AND NEGATIVE-ION MODES... 

An aromatic compound A on treatment with aqueous ammonia and heating forms compound B which on heating with and KOH forms a compound C of molecular formula CgH N. Write the structures and lUPAC names of compounds A, B and C. 

The names of compounds are capitalized only at the start of a sentence, in which case only the hrst letter is capitalized. Even at the start of a sentence, words that signal stereochemistry—such as ortho (o), meta (m), para (p), ds, and trans—are lowercase (and italicized). 

The recent TUPAC Compendium of Chemical Terminology—The Gold Book recommends that the name of compounds having the structure R2N—O" R2N +—0 is more appropriately that of aminoxyl radicals . The synonymous terms nitroxyl radical or nitroxide are accordingly not desirable, even though quite popular in various fields of science and technology. This chapter follows a previous chapter of the series and, for this historical reason, retains the old terminology of the compounds in the title, but this use will be discontinued from now on in the text. 

A name is given to each elementary substance, that is, each substance which has not been decomposed the name generally expresses some characteristic property of the substance, or tells something about its origin or the place of its discovery. The names of compounds are formed by putting together the names of the elements which combine to produce them and the relative quantities of these elements are indicated either by the use of Latin or Greek prefixes, or by variations in the terminal syllables of the names of the elements. 

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