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. 1891 Excerpt: ...can be represented in an extremely simple fashion, retaining the ordinary notation CRjR2CR3R4, but giving real significance to the successive order in the groups RjR2 and R3R4. Prediction of isomerism.--Besides the relative position of the four groups RjR2R3R4 which has been described, there is a second position which ...
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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. 1891 Excerpt: ...can be represented in an extremely simple fashion, retaining the ordinary notation CRjR2CR3R4, but giving real significance to the successive order in the groups RjR2 and R3R4. Prediction of isomerism.--Besides the relative position of the four groups RjR2R3R4 which has been described, there is a second position which equally satisfies the conditions laid down, but is nevertheless not identical with the first; in short, the groups Ra may be situated in the same plane with R3R4, and united each to the same atom of carbon as before, but with this difference, that R; is opposite R4, and R2 opposite R3, as shown by the symbol CRjR2 CR4R3. Consequently we are in a position to predict an isomerism not accounted for by the old structural formulae, and it is clear that this isomerism is to be expected equally in all cases where the group Rj is different from R2, and R3 from R4, no matter whether there is equality or not between the groups attached to different carbon atoms, so that the case CRjR2CRjR;i involves the same prediction of isomerism. II. Verification Of The Fundamental Conception. General character of the isomerism foreseen in the case of doubly-linked carbon atoms.--We propose first to discuss the nature of the isomerism in question, because we have to notice a marked difference between the new isomerism and that which results from the presence of the asymmetric carbon atom. In fact, according to the principles laid down, there is here neither dissymmetry nor enantiomorphism in the atomic structure. So that there is no question of rotatory power with contrary sign in the two cases, or of the particular hemihedral crystalline form which accompanies this optical property; these properties in fact, as we shall see, are absent. But if these distinctive trai...
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