Early nomenclature

Before 1940, compound (I) would have been called diethyl chloro-phosphate without any good reason. One of the fundamental rules 

The chlorophosphate is derived from the phosphate (II) by the replacement of OH, not H, by chlorine, hence the designation chloro- 

This difficulty was overcome by describing (I) as diethyl chloro phosphonate, and the use of this term was later endors by the 

Nomenclature Committee of the Publication Committee of tha Chemical Society. 

Analogy with sulphur chemistry is useful here. If one OH grcxy in sulphuric acid is replaced by a H atom, the hypothetical sulphoois acid (IV) is obtained. 

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In the early nomenclature this sugar was termed L-xylose. 

By comparing the above summaries, it is seen that the ortho compound of the earlier chemists is identical with the present meta nitrotoluene, and vice versa. That the early view was incorrect may be further proved by investigating the properies of the meta compounds. In all reactions the meta compounds react differently from the ortho and para compounds. For instance, in the nitration of toluene, the ortho and para nitrotoluenes are formed in large amounts, and the meta in small amounts. Further, when the mono-nitrotoluenes are nitrated to dinitrotoluene, the ortho and para mononitrotoluenes are very easily nitrated further, and the meta difficultly so. In other words, the ortho and para compounds form one part of the class, while the meta stands alone as the other part. With the early nomenclature, the meta and para would be placed together, while the ortho would stand alone. If, now, this view of the matter is accepted. Von Richter s statement becomes entirely correct. 

Besides the nomenclature work done by the general ACS nomenclature committee, sporadic early nomenclature work was done by committees of the ACS divisions. It was not until the need for more nomenclature activity, made evident in the chemical work done during World War II, was emphasized by Howard S. Nutting and Stewart S. Kurtz, Jr., that nomenclature work by committees of the divisions really began in earnest. Now there are numerous divisional nomenclature committees a list is presented in Table I. The work on pectic substances by a committee of the ACS Division of Agricultural and... 

Carbon atoms are the most frequently found radical centers with their electron septet occupying an intermediate position between the carbenium ions and the carbanions. Radicals are often called free radicals, a term that arose from early nomenclature systems in which a radical was a substituent group that was preserved as a unit through a chemical transformation. Thus, the CH3 group as a substituent was known as the methyl radical, so a neutral CHj group became a free radical. The terms radical and free radical are now used interchangeably. Some common examples of radicals include the methyl radical (1), vinyl radical (2), phenyl radical (3), triphenylmethyl radical (4), allyl radical (5), and benzyl radical (6) (Figure 4.1). 

There is another fluorescence type that was not specified in early nomenclature schemes that has now been widely observed and also is a component in some PARAFAC models (Coble, unpubhshed). This type of fluorescence has been observed in very clear open ocean surface waters and is most likely the result of extensive photobleaching. Figure 3.5 shows the EEM for a sample collected in the Gulf of Mexico along with the PARAFAC component that is similar. 

We make one important note here regarding nomenclature. Early explanations of CIDNP invoked an Overhauser-type mechanism, implying a dynamic process similar to spin relaxation hence the word dynamic m the CIDNP acronym. This is now known to be incorrect, but the acronym has prevailed in its infant fomi. 

Nomenclature is the compilation of descriptions of things and technical terms in a special field of knowledge, the vocabulary ofa technical language. In the history of chemistry, a systematic nomenclature became significant only rather late. In the early times of alchemy, the properties of the substance or its appearance played a major role in giving a compound a name. Libavius was the first person who tried to fix some kind of nomenclature in Alckeinia in 1,597. In essence, he gave names to chemical equipment and processes (methods, names that are often still valid in our times. 

The solution to this problem is to use more than one basis function of each type some of them compact and others diffuse, Linear combinations of basis Functions of the same type can then produce MOs with spatial extents between the limits set by the most compact and the most diffuse basis functions. Such basis sets arc known as double is the usual symbol for the exponent of the basis function, which determines its spatial extent) if all orbitals arc split into two components, or split ualence if only the valence orbitals arc split. A typical early split valence basis set was known as 6-31G 124], This nomenclature means that the core (non-valence) orbitals are represented by six Gaussian functions and the valence AOs by two sets of three (compact) and one (more diffuse) Gaussian functions. 

Nomenclature. The compound on which the enzyme acts is known as the substrate. The name of the enzyme is now usually obtained by adding the termination ase to the name of the substrate. Thus an enzyme which hydrolyses an ester is known as an esterase. Nevertheless the older names of many enzymes still persist owing to their early disco ieiy. In some cases the name of the enzyme indicates the reaction w hich it catalyses, e.g. oxidase. 

Heteroeyeles structurally based on the phenalene ring system form an interesting elass, frequently possessing distinetive eolours. With nitrogen as the central atom we have the unstable 9b-azaphenalene (24), whieh has only fairly reeently been prepared and is still comparatively little studied (76JCS(Pl)34l). The cyclazine nomenclature is commonly applied to this and related compounds thus, (24) is (3.3.3)cyclazine. With further aza substitution, in positions alternant to the central atom, their stability increases the heptaazaphenalene (25) is (thermally) a very inert compound, derivatives of which, e.g. the triamine, have been known since the early days of organic chemistry (see Chapter 2.20). 

The word locomotive means, literally, power for moving from one place to another. Early locomotives were given the nickname iron horse because of their material and function. Most European languages use similar nomenclature for railroads, as in the French chcinin dc fer, Italian ferrovie, Spanish ferroarril and German eisenh hn, all of which mean iron way in literal English. 

Carb-O. Historical development of carbohydrate nomenclature 0.1. Early approaches 0.2. The contribution of Emil Fischer 0.3. Cyclic forms 0.4. Nomenclature commissions 2-Carb-l. Definitions and conventions... 

Carb-0. Historical development of carbohydrate nomenclature [15] 2-Carb-O.l. Early approaches... 

The literature in this field is confusing because of a somewhat haphazard method of nomenclature that has arisen historically. This is compounded by some mistakes in structure determination, reported in early papers, and which are occasionally quoted. The first part of this chapter deals with nomenclature and with a brief overview of early work. Subsequent sections deal with the formation and metabolism of di-D-fructose dianhydrides by micro-organisms, and the formation of dihexulose dianhydrides by protonic and thermal activation. In relation to the latter topic, recent conclusions regarding the nature of sucrose caramels are covered. Other sections deal with the effects of di-D-fructose dianhydrides upon the industrial production of sucrose and fructose, and the possible ways in which these compounds might be exploited. An overview of the topic of conformational energies and implications for product distributions is also presented. 

Since the early 1970s a panel convened by the International Union of Pure and Applied Chemistry and the International Union of Biochemistry and Molecular Biology has been working to formulate recommendations for carbohydrate nomenclature that meet developing needs of research and electronic data handling, while retaining links to the established literature base on carbohydrates. The realization of these endeavors is presented here in the final document Nomenclature of Carbohydrates, which provides a definitive reference for current researchers, both in the text version and in the version accessible on the World Wide Web (http //www.chem.qmw.ac.uk/iupac/2carb/), where amendments and revisions are maintained. 

As early as 1902 Gomberg suggested that the word carbonium was inappropriate for such species because onium signifies a covalency greater than that of the neutral atom. But the nomenclature went on till about 1964 when George Olah and his coworkers found evidence by mass spectroscopy... 

Nelson DR, Kamataki T, Waxman DJ, et al. (1993) The P450 superfamily update on new sequences, gene mapping, accession numbers, early trivial names, and nomenclature. DNA Cell Biol 12 1-51... 

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