Anion nomenclature system

Nitric, sulfuric, and phosphoric acids have important variations with different numbers of oxygen atoms. The acid and anion nomenclature system in Table 6.3... 

Along with the theory of coordination, Werner proposed5 a system of nomenclature for coordination entities which not only reproduced their compositions but also indicated many of their structures. Werner s system was completely additive in that the names of the ligands were cited, followed by the name of the central atom (modified by the ending ate if the complex was an anion). Wemer also used structural descriptors and locants. The additive nomenclature system was capable of expansion and adaptation to new compounds and even to other fields of chemistry. 

If the cation and anion exist in only one common charged form, there is no ambiguity between formula and name. Sodium chloride must be NaCl, and lithium sulfide must be Li2S, so that the sum of positive and negative charges is zero. With many elements, such as the transition metals, several ions of different charge may exist. Fe ", Fe + and Cu+, Cu + are two common examples. Clearly, an ambiguity exists if we use the name iron for both Fe + and Fe + or copper for both Cu" and Cu +. Two systems have been developed to avoid this problem the Stock system and the common nomenclature system. 

Names of ionic compounds are derived from the names of their ions. The name of the cation appears first, followed by the name of the anion. In the Stock system for naming an ion (the systematic name), a Roman numeral indicates the charge of the cation. In the older common nomenclature system, the suffix -ous indicates the lower of the ionic charges, and the suffix -ic indicates the higher ionic charge. 

The following example gives you the opportunity to practice what you have learned about acid and anion nomenclature. If you have memorized what is necessary and know how to apply the rules, you will be able to write the required names and formulas with reference to nothing other than a periodic table. If you have really mastered the system, you will be able to extend it to the last substance in each column. 

The Stock Oxidation-Number System. Stock sought to correct many nomenclature difficulties by introducing Roman numerals in parentheses to indicate the state(s) of oxidation, eg, titanium(II) chloride for TiCl2, iron(II) oxide for FeO, titanium(III) chloride for TiCl, iron(III) oxide for Fe203, titanium(IV) chloride for TiCl, and iron(II,III) oxide for Fe O. In this system, only the termination -ate is used for anions, followed by Roman numerals in parentheses. Examples are potassium manganate(IV) for K2Mn02, potassium tetrachloroplatinate(II) for K PtCl, and sodium hexacyanoferrate(III) for Na3Fe(CN)3. Thus a set of prefixes and terminations becomes uimecessary. 

A remarkable variety of compounds in the Ca-(B,C,N) system has opened a window for research in related fields. With the elements boron, carbon and nitrogen, substance classes such as borocarbides, boronitrides, and carbonitrides can be considered to contain anionic derivatives of binary compounds B4C, BN, and C3N4. Until now, most compounds in these substance classes have been considered to contain alkali, alkaline-earth, or lanthanide elements. Lanthanide borocarbides are known from the work of Bauer [1]. Lanthanide boronitrides represent a younger family of compounds, also assigned as nitridoborates [2] following the nomenclature of oxoborates. 

The nomenclature of boron compounds involves some intricacies. IUPAC rules allow the terms borabenzene or borinine for 2 the older name borin has become obsolete with the recent revision of the extended Hantzsch-Widman system (6). Anions 4 are termed boratabenzene ions an alternative would be borininate instead of the earlier borinate (7). 

This system is additive and was developed originally to name coordination compounds, although it can be used in other circumstances when appropriate. For a discussion, see the Nomenclature of Inorganic Chemistry, Chapter 10. The compound to be named is considered as a central atom together with its ligands, and the name is developed by assembling the individual names of the constituents. This system has also been applied to name oxoacids and the related anions. Coordination names for oxoanions are cited in the examples throughout the text, and they are presented in detail in Section 4.4.5 (p. 69). 

The terms in Equation 1.3 (Malkin s autocatalytic model) are described in Nomenclature. In Malkin s autocatalytic model, the concentration of the activator, [A], is defined as the concentration of the initiator times the functionality of the initiator. For a difimctional initiator [e.g., isophthaloyl-bis-caprolactam, the concentration of the activator (acyllactam) is twice the concentration of the initiator]. The term [C] is defined as the concentration of the metal ion that catalyzes the anionic polymerization of caprolactam. In a magnesium-bromide catalyzed system, the concentration of the metal ion is the same as the concentration of the caprolactam-magnesium-bromide (catalyst) because the latter is monofunctional. 

The following nomenclature has been used in this review The ring system is named as the appropriate heterocation and the exocyclic group carrying the negative charge is named as the appropriate anion (i.e., olate, thiolate, aminide, or methylate). Thus, compounds of type 9 are named as... 

Polymeric chain, band- and sheet silicate structures have been discussed previously (page 742), and it should not be surprising to learn that cyclic silicate anions, such as [Si3Oy]ft and [Si601B]l2 (Fig. 16.28) are known. These anions are sometimes referred to as metasilicates in line with the older system of nomenclature, which assigned vrtlto to the most fully hydrated species [as in orthosilicic acid." Si(QH)J and metu to the acid (and anion) from which one mole of water has been removed [either in fact or formally for example, "metasilicic acid," OSi(OH)2]. 

When writing a chemical formula, you learned that you write the metal element first. Similarly, the metal comes first when naming a chemical compound. For example, sodium chloride is formed from the metal sodium and the non-metal chlorine. Think of other names you have seen in this chapter, such as beryllium chloride, calcium oxide, and aluminum oxide. In each case, the metal is first and the non-metal is second. In other words, the cation is first and the anion is second. This is just one of the rules in chemical nomenclature the system that is used in chemistry for naming compounds. 

A system of coordination nomenclature is used for anions containing H , and, thus, [A1H4] is called the tetrahydridoaluminate(l—) ion anions containing boron are exceptions, and [BH4] is the tetra-hydroborate(l-) ion. 

---