Nomenclature Considerations

Vegvari, A., and Guttman, A. (2006). Theoretical and nomenclatural considerations of capillary electrochromatography with monolithic stationary phases. Electrophoresis 27, 716—725. 

It should be understood that the choice of this name, based mainly on practical nomenclature considerations, does not define the real electronic structure of the molecule, which will be discussed later in Section VI. 

The largest part of the subject is the nomenclature of organic compounds, simply because there are so many of them, and of such diverse nature. The types of compounds and stmctures differ considerably among organic, inorganic, and biochemical substances, and each of their respective nomenclatures has developed somewhat differendy, although not independendy. Macromolecular nomenclature and pharmaceutical nomenclature have practical requirements of their own. It is therefore appropriate to treat each of these several areas separately. 

Elemental composition, ionic charge, and oxidation state are the dominant considerations in inorganic nomenclature. Coimectivity, ie, which atoms are linked by bonds to which other atoms, has not generally been considered to be important, and indeed, in some types of compounds, such as cluster compounds, it caimot be appHed unambiguously. However, when it is necessary to indicate coimectivity, itaUcized symbols for the connected atoms are used, as in trioxodinitrate(A/,A/), O2N—NO . The nomenclature that has been presented appHes to isolated molecules (or ions). Eor substances in the soHd state, which may have more than one crystal stmcture, with individual connectivities, two devices are used. The name of a mineral that exemplifies a particular crystal stmcture, eg, mtile or perovskite, may be appended. Alternatively, the crystal stmcture symmetry, eg, rhombic or triclinic, may be cited, or the stmcture may be stated in a phrase, eg, face-centered cubic. 

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 (lUPAC Provisional Recommendation 83.2). Proposals for a suffix to indicate such structures are under consideration (1982). 

Meanwhile, the A convention combined with replacement nomenclature may be used to indicate the changed bonding number of the anionic site, and the suffix -ide appended, as shown in (202) and (203). Proposals for an anionic replacement prefix, analogous to the cationic -onia prefixes, are under consideration. 

Protonation of the anion [SN2] by acetic acid in diethyl ether produces the thermally unstable sulfur diimide S(NH)2. Like all sulfur diimides, the parent compound S(NH)2 can exist as three isomers (Scheme 5.5). Ab initio molecular orbital calculations indicate that the (cis,cis) configuration is somewhat more stable than the (cis,trans) isomer, while the (trans,trans) isomer is expected to possess considerably higher energy. The alternative syn,anti or E,Z nomenclatures may also be used to describe these isomers. The structures of organic derivatives S(NR)2 (R = alkyl, aryl) are discussed in Section 10.4.2. 

According to these consideration the diamino-substituted phosphenium (an alternative suggestion for its nomenclature is phosphanylium) cation, 5, and the phosphanetriylammonium (iminophosphenium) cation, 6, possess the largest intrinsic (gas phase) stabihties. Since in the X-ray structures the molecules are to a first-order isolated, this theoretical stability scale determined for the gas phase should also mimic the various trends of the stabilities of the cations and their chelation behaviour. The methylenephosphenium, 7, and the PjH cations, 8, suffer from poor stabihties. On the other hand the phosphirenium cation, 11, is considered to be fairly well stabilized. It is due to n-electron delocalisation of the positive charge in the phosphirenium cation. Intermediate cases in stabihty are the PO+ (9) and PS+ cations (10). Of further interest are the frontier orbital considerations, as shown in Fig. 2. 

Mastocytomas and diffuse cutaneous mastocytosis are further manifestations of cutaneous mastocytosis (CM) [9]. Solitary mastocytomas are common in children. Most are present at birth or develop in infancy. These lesions are flat or mildly elevated, well demarcated, solitary yellowish red-brown plaques or nodules, typically 2-5 cm in diameter. Diffuse cutaneous mastocytosis is a rare disorder characterized by diffuse mast cell infiltration of large areas of the skin that presents in infants in the first year of life. Severe edema and leathery indurations of the skin leads to accentuation of skin folds (pseudo-lichenified skin) and a peau-dbrange-like appearance. Systemic complications include hypotension and gastrointestinal hemorrhage. Infants and young children with considerable mast cell infiltration of the skin sometimes exhibit blister formation in the first 3 years of life. MPCM and other forms of CM have been classified in a consensus nomenclature (table 1) [10]. 

Many of the new insecticidal chemicals are complex organic materials with long and complicated names. There is need for simple common names. Without simplified terminology costly losses may result from relatively minor errors in nomenclature. Coined names must be protected if they are to remain available for general use, and must be defined with sufficient accuracy to assure that a standard product will be marketed. Selection of such names requires cooperative consideration by many agencies. Chemists can make important contributions to this undertaking. 

Assist in Standardization of Nomenclature. The profusion of trade names, initials, numbers, and combinations thereof for pesticides contributes to misuse and errors in the handling of these preparations. The coining of common or generic names for pesticides is a recent and commendable innovation in this field of science. It presents many problems which require the services of many groups. The many years of experience of the Council on Pharmacy and Chemistry in the development of generic names for drugs is at the disposal of the committee in its consideration of nomenclature problems. 

Wherever possible, official definitions of IUPAC, ISO and other international organizations have been used, in particular in the Glossary of Analytical Terms compiled at the end of the book. However, uniformity could not be achieved in every case. In a few instances, special comments and proposals (characterized as such) have been added. Although progress in the field of harmonization of nomenclature and definitions has been considerable, some things still remain to be done. 

Chapter i gives a broad general historical survey of the work, and the more precise details of nomenclature, experimental procedures and theoretical considerations are reserved for later chapters. 

In view of the rapid growth of the organic chemistry of phosphorus since 1939, considerable attention has been paid to nomenclature. It has not always been easy to achieve agreement among workers in different parts of the world as to the most logical, convenient and simple system. It may not be out of place therefore to trace the inner history of some of the changes and developments that have taken place. However, the reader who is interested only in the details of the nomenclature as now accepted should turn at once to p. 25. 

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