Investigations of Infra-red Spectra ...: pt. I. Infra-red absorption spectra. pt. II. Infra-red emission spectra

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Carnegie institution of Washington, 1905
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Pagina 113 - nucleus," in common with many of the compounds studied, which causes absorption bands, characteristic of the great groups of organic compounds, but we do not know what that " something " is. The presence of these groups of
Pagina 322 - On the .other hand, the other bands increase in intensity with increase in pressure, become a maximum at about 2 mm. pressure, then decrease in intensity with a further increase in pressure, which agrees with observations in the visible spectrum. All lines increase in intensity with increase in current as found in the visible spectrum.
Pagina 319 - ... which is proportional to the mean square of the ionic speeds will attain a maximum. At a still lower pressure, on account of the scarcity of the molecules, there will be fewer collisions in a given time, the ionization will decrease and the " electrical temperature
Pagina 109 - Of course, as is well known now, the nearest approximation to such a law is Balmer's Law and the numerous other convergent series formulae used by Kayser and Runge, and by others. Nevertheless, in spite of these warnings, and fully realizing the danger from lack of dispersion, experimental errors, etc., I venture to call attention to certain marked absorption bands which occur so frequently, in positions which so closely fulfill this relation, that it is necessary...
Pagina 320 - ... the neutral gas molecules. The gas molecule as a whole will suffer an increase in its kinetic energy, and, in colliding with other molecules, will cause a rise in the thermal temperature of the gas. With increase in pressure, ie, in the number of gas molecules, the number of collisions will increase, the intensity of the thermal radiation will increase but will not pass through a maximum, as is true of the other bands, because a stage will be arrived at where there will be a decrease in the ionization...
Pagina 320 - At a high pressure the constricted portion of the vacuum tube is the hotter while at low pressure it is quite cool, and the region surrounding the electrodes is the hotter. Third, the emission increases with the pressure (equivalent to an increase in the thickness of the emitting layer) and approaches a limiting value. Paschen (loc. cit.) has found for CO2 at atmospheric pressure, in a brass tube heated by a bunsen burner that a column 7 cm. long emitted and absorbed energy just as strong as a column...
Pagina 105 - Fig. 10. Illustrating the persistence of the benzene bands at 3.25/7 and 6.75^ in the spectra of its derivatives. Considering the bands of ammonia and of the compounds containing NH2, or certain ones containing nitrogen, the coincidence appears to be somewhat accidental. Farther in the infra-red we have numerous cases of the coincidence of absorption bands. As a whole the most definite conclusion we can draw, at present, is that the alcohols have a characteristic band at about 2.95 // just as the...
Pagina 111 - ... using a radiometer, two mirror spectrometers and rock salt prism. Out of a total number of at least 135 compounds examined with the rock salt prism, 131 have been recorded in this paper. They include solids, liquids, and gases. In addition to this, 19 compounds were examined to 2.7 p, using a quartz prism.
Pagina 97 - ... tion of heat waves, it will simplify matters to discuss each of these topics separately. A few transmission curves are included to give the reader an idea of their general appearance. Effect of Structure. — In order to learn what effect a group of atoms in a molecule has upon infra-red absorption spectra, the most logical procedure is to study isomeric compounds in order to determine fully that the phenomenon is intramolecular, and after that attempt to locate the particular group of atoms...
Pagina 98 - H atoms in benzene do we find bands, eg, 3.43 fjt, in common with those of the chain compounds. If, then, we had no knowledge of organic chemistry, the evidence presented here would be sufficient to conclude that we are dealing with two distinct classes of compounds.

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