Nomenclature colloquial

Ruthless adherence to full systematic nomenclature throughout these volumes would serve little useful purpose. While it is necessary for the Chemical Abstracts indexes to avoid colloquial forms, most of our contributors seem to agree that insistence on the use of, e.g. 4(17f)-pyridinone at every point, rather than the traditional but less precise 4-pyridone , produces a pedantic effect on the English style. So old-fashioned forms like pyridone coexist here with systematic names, the choice being dictated by the individual authors of the chapters. 

It is often the case that chemists involved or familiar with ethylene oxide (oxiran) chemistry refer to these cyclic oligomers as EO-4, EO-6 and EO-7 respectively. Such designations are informal if not colloquial but, like any name, are useful if they correctly convey an idea. The difficulty with these informalities, indeed with the crown nomenclature system is that it cannot adequately deal with complicated structures or even isomers of simple ones. 

In the previous paragraphs a brief account has been given of the fundamental aspects of the crystallographic description of the structures and structure types of solid phases. A number of symbols and names have been defined and their application to intermetallic compounds exemplified. It must, however, be underlined that both for historical reasons and for the need to improve classification and interpretation of the structural characteristics of intermetallic phases, other symbols and nomenclature criteria have been invented. Some of them have a mathematical basis, others are more colloquial. A selection of these criteria will be given in the following. 

We close this section with one more note on careful nomenclature. A code renders a model into a set of instructions that can be understood by a digital computer. Thus, if one applies a particular model, let us say the molecular mechanics model called MM3 (which will be described in the next chapter) to a particular problem, say the energy of chair cyclohexane, the results should be completely independent of which code one employs to carry out the calculation. If two pieces of software (let s call them MyProg and YourProg) differ by more than the numerical noise that can arise because of different round-off conventions with different computer chips (or having set different tolerances for what constitutes a converged calculation) then one (or both ) of those pieces of software is incorrect. In colloquial tenns, there is a bug in the incorrect code(s). 

Because of the cumbersome and usually exasperating nature of the von Baeyer system of formal nomenclature,422 especially when applied to complex polycyclic systems, a colloquial nomenclature has been developed for the higher poly-quinanes.415,42 The system applies only to polycondensed, fused, equal-size ringed molecules (no spiro fusions) and states the total number of carbon atoms, the number of basic rings, and their size. An indicator of ring juncture stereochemistry is also required on occasion, a symmetry designation must be added. Thus, all-cis-484 is (Q-C 14-tetraquinane and all-cis-485 is(C2)-Ci4-tetraquinane. 

GLOSSARY OF MISCELLANEOUS TERMS AND TECHNIQUES USED IN NOMENCLATURE, INCLUDING COLLOQUIAL TERMS... 

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