Cations nomenclature of, 45

In this part we shall use the nomenclature of Si lien and Martel 1 (76) to define stability constants, medium and experimental techniques. We shall only deal with overall stability constants of the cation M with the ligand L according to reaction (25)... 

The abbreviations for the investigation methods are also taken from the nomenclature of Sillen and Martel 1 (76) aiex = anion exchange cal = calorimetry ciex = cation exchange dis = distribution between two phases est = estimate red = e.m.f. with redox electrode sp = spectrophotometry. Our selected data, rather limited in number, arise from the present status of the IAEA assessment of inorganic complexes of the actinides (12). 

Cationic dyes, nomenclature of, 25 Cellular exchanges, thiazolium salts as activators in, 80... 

Regulating growth factors, of plants, thiazolium salts as, 80 Resonance theory, 68 Rhodacyanines, see Neutrorhodacyanines cationic, tables of, 180 nomenclature of. 27 nonionic dyes, tables of. 184 synthesis of, 64... 

Unlike the lanthanides, the actinides U, Np, Pu, and Am have a tendency to form linear actinyl dioxo cations with formula MeO and/or Me02. All these ions are paramagnetic except UO and they all have a non-spherical distribution of their unpaired electronic spins. Hence their electronic relaxation rates are expected to be very fast and their relaxivities, quite low. However, two ions, namely NpO and PuOl", stand out because of their unusual relaxation properties. This chapter will be essentially devoted to these ions that are both 5/. Some comments will be included later about UOi (5/°) and NpOi (5/ ). One should note here that there is some confusion in the literature about the nomenclature of the actinyl cations. The yl ending of plutonyl is often used indiscriminately for PuO and PuOl and the name neptunyl is applied to both NpO and NpOi. For instance, SciFinder Scholar" makes no difference between yl compounds in different oxidation states. Here, the names neptunyl and plutonyl designate two ions of the same 5f electronic structure but of different electric charge and... 

Additive nomenclature1 is based on the combination of element names or roots of element names and/or ligand names. The simplest and oldest additive nomenclature is binary nomenclature that expresses two components, e.g. sodium chloride. The cationic or electropositive portion of the compound expressed in a binary name is the element name unchanged or a group name ending in -ium , and the anionic or electronegative portion of a compound expressed in the name ends in -ide, -ite or -ate. The proportions of cations and anions in neutral compounds are indicated by Stock numbers or simple or multiplicative prefixes (see Section 3.3.2). Additive nomenclature denotes composition. For examples see Table 1. 

We use the term carbocation to refer to any cationic carbon species. For more about the nomenclature of carbocations, see Chapter 6, p. 288. 

We now extend the structural basis set for cobalt(III) hexaamines with one additional structure with relatively long Coin-N bonds. The [Co(tmen)3]3+ cation (tmen = 2,3-dimethylpropane-2,3-diamine) is a highly strained species with long Com-N bonds because of the four methyl substituents (see Fig. 17.12.1). The structure of the cation has been determined by an X-ray diffraction study, and the conformation in the crystal has been defined as 065 (see Section 17.3 for the nomenclature of the conformers). Due to the elongation of the Com-N bonds to 1.997 A, there is a remarkable shift in the ligand field spectra (the first d-d transition ( Ai- ) is at 515 nm vs 470 nm for [Co(en)3p ) and the redox potential (-0.18 V vs +0.28 V)[56>231]. 

Nomenclature of Carboxylic Acid Salts Salts of carboxylic acids are named simply by naming the cation, then naming the carboxylate ion by replacing the -ic acid part of the acid name with -ate. The preceding example shows that sodium hydroxide reacts with acetic acid to form sodium acetate. The following examples show the formation and nomenclature of some other salts ... 

Figure 5 Structure and nomenclature of oxygen/sulfur five-membered cations.

We use the term silylium ion for R3Si+, rather than silicenium ion, silylenium ion, or silyl cation, thus following IUPAC recommendations. See Nomenclature of Inorganic Chemistry G.J. Leigh, Ed. Blackwell Oxford, U.K., 1990, p. 106. 

In the first part of this section the elucidation of the mechanism will be presented, while the second part will be devoted to a discussion of the effect of cations on the viscoelastic properties. Both of these topics are grouped together because, as will be shown below, the relaxation mechanism of all the polymers discussed here is perfectly normal, i.e., simple molecular flow, [or the a mechanism according to the nomenclature of Ferry (27, 28, 29) and Hoff 37a), and the materials can thus be called chemically inactive. Finally, the work on viscoelasticity of bulk organic polyelectrol5des will be mentioned. The next section will be devoted to a discussion of the viscoelastic properties of materials in which, in addition to the a mechanism, bond interchange (the x mechanism) is also encoimtered, the chemical (hence x) activity being due to catalysis by transition metal ions. 

IR-1.5.3.2 Compositional nomenclature IR-1.5.3.3 Substitutive nomenclature IR-1.5.3.4 Additive nomenclature IR-1.5.3.5 General naming procedures IR-1.6 Changes to previous IUPAC recommendations IR-1.6.1 Names of cations IR-1.6.2 Names of anions IR-1.6.3 The element sequence of Table VI IR-1.6.4 Names of anionic ligands in (formal) coordination entities IR-1.6.5 Formulae for (formal) coordination entities IR-1.6.6 Additive names of polynuclear entities IR-1.6.7 Names of inorganic acids IR-1.6.8 Addition compounds IR-1.6.9 Miscellaneous... 

The Nomenclature of Hydrides of Nitrogen and Derived Cations, Anions, and Ligands,... 

Constructing a substitutive name generally involves the replacement of hydrogen atoms in a parent structure with other atoms or atom groups. Related operations, often considered to be part of substitutive nomenclature, are skeletal replacement (Section IR-6.2.4.1) and functional replacement in oxoacid parents (Section IR-8.6). Note that some operations in parent hydride-based nomenclature are not substitutive operations (e.g. formation of cations and anions by addition of H+ and H, respectively, cf. Sections IR-6.4.1 and IR-6.4.5). Names formed by the modifications of parent hydride names described in those sections are still considered part of substitutive nomenclature. 

To avoid ambiguity, the name should not be used as the root for the systematic nomenclature of carboca-tions. The corresponding difficulty confused carbonium ion nomenclature for many years. For example, the term ethylcarbonium ion has at times been used to refer either to CH3CH2+ (ethyl cation) or (correctly) to CH3CH2CH2+ (propyl cation). 

We begin with a brief overview of the types of cations and anions that are known in the field, as of mid-2008. Part of our goal here is to provide a guide to some of the nomenclature that follows in the remainder of the chapter. 

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