This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...formulas but such a method is not here available and the ordinary structural formulas must suffice. The following compounds illustrate these substitutions and the nomenclature of them: For convenience in naming compounds, C6H5, is frequently called phenyl, and C6H4, phenylene. The term "hydroxy" in these names is often ...
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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1905 Excerpt: ...formulas but such a method is not here available and the ordinary structural formulas must suffice. The following compounds illustrate these substitutions and the nomenclature of them: For convenience in naming compounds, C6H5, is frequently called phenyl, and C6H4, phenylene. The term "hydroxy" in these names is often abbreviated to "oxy." Thus, C6H5HO is called oxybenzene. The conditions of symmetry in benzene are such that no isomerism is to be expected (and none has been observed) in the compounds formed by a single substitution of the hydrogen. Hence, phenol, hydroxybenzene, is identical in nature no matter how prepared. When two or more hydrogen atoms are replaced, isomerism at once becomes possible, and instances become very numerous when several different substituting molecules are introduced. To aid in expressing the formulas of these isomeric bodies, and also in distinguishing them by name, the normal benzene-molecule is represented by a hexagon which, when unmodified, stands for C6H6; it is termed a "ring-symbol." A symbol or formula at any angle of this hexagon indicates that an atom of hydrogen is replaced by the body represented by that symbol or formula. The annexed diagrams will show the detailed structural formula and ring-symbol. The carbon atoms are here again represented by dots. X represents any monad elements or radicle. The position of the substituting body is immaterial in this case, but it is usually placed at the upper angle. When two hydrogen atoms are replaced three isomeric bodies will be formed, whether the replacement is by the same or different bodies. To assist in indicating, the angles are distinguished by numbers in the order of those on a clock, thus: 4 Substitution of two hydrogen-atoms are ...
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