Sur le spectre d'absorption de quelques corps organiques incolores et ses relations avec la structure moléculaire

Spring, W. Bull. Acad. roy. Belgique (1897), 33(3), 165-95; SciFinder (Chemical Abstracts Service: Columbus, OH); https://scifinder.cas.org (accessed July 8, 2010).

The available, very detailed work follows the observations of the author's on the color water. During view of very thick layers of organic products author finds also the so-called uncolored compounds colored and observes that all compounds, which contain a hydroxyl group show a blue color, which all the more approaches the color water, when those is short the OH the following carbon chain. If the hydroxyl group is missing, then the products possess more or less deep, gold-yellow color. The spectral investigations more numerously, in groups of matching, organic compounds leads to the following general conclusions: The so-called uncolored organic compounds give a spectrum without absorption bands, if you consist mole of carbon chains, around those the heterologous atoms or groups in a homogeneous or symmetrical way distributed are. If these heterologous atoms or groups are however concentrated at an end of a chain or combines, then the compounds concerned give spectra with absorption bands. The number of the absorption bands seems to stand in direct relation to the number of the hydrocarbon remainders, which one can differentiate with respect to the examined compound; thus an ester two strips, their the acid radical, give whose different one corresponds to the alkyl, while the acid or the alcohol spectra with ever only one strip supplies. The position of the strips seems to be characteristic for each of the groups and remains generally the same, much with which other group the first being connected likes to apply only with more complicated compounds seems this rule not. If two groups are very closely with each other connected, then the positions of the individual absorption bands changed by the mutual influence (methyl benzene), it unite occasionally even to gang. Generally author regards his observations as a support of the ideas and the modern theory of the organic compounds, introduced by Kekuele into the science.

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