Ein Neues Drehprismenverfahren zur Photographischen Ermittlung der Dispersion, and Applications of Raman Spectra to Chemistry

Author: Anderson, Thomas Foxen

Year: 1936

Degree: Dissertation (Ph.D.)

Advisor: Yost, Don M.

Committee Member: Unknown, Unknown

Option: Chemistry

DOI: 10.7907/07vb-w743

Abstract

I. Ein Drehprismenverfahren zur Ermittlung der Dispersion

An inexpensive ultraviolet spectrograph using concave mirrors instead of lenses is described. After trial determinations of the known dispersion of quartz and KCl, the instrument was used to determine the dispersion of CsCl to 2265Å. Refractive index results are good to one unit in the fourth decimal place.

II. Applications of Raman Spectra to Chemistry

A. The Raman Spectra and Molecular Constants of Phosphorus Trifluoride and Phosphine.

The Raman frequencies of PF3 and PH3 are reported together with the molecular constants and entropies of PH3, PF3, PCl3, AsF3, and AsCl3. From these data ΔF298 is calculated for PH3 and PCl3 together with S*298 for P(s, white).

B. The Entropy of Phosphorus.

A more accurate value of S*298 for P(s, white) is calculated using recent electron diffraction and Raman spectrum results for P4. This leads to a more accurate value of ΔF298 for PCl3

C. The Raman Spectrum of Arsenic Trichloride.

It is pointed out that the assignment of frequencies of AsCl3 made in an article by Brodskii and Sack is contradicted by polarization experiments. From this is follows that a central force treatment alone does not suffice for the treatment of the AsCl3 type of molecule as Brodskii and Sack assert.

D. The Raman Spectrum of Deuterium.

The Raman spectrum of D2 is reported. From the frequencies of the two rotation lines and the one vibration line observed it is concluded that the potential function for D2 is the same as that for H2. This suggests that M-D potential functions are equal to those for M-H.

E. The Raman Spectrum of Tetraethyl Silane. Vibrational Resonance in Tetraalkyls.

The Raman Spectrum of Si(C2H3)4 is reported. The presence of extra lines in its spectrum and in the spectra of other tetraalkyls is ascribed to vibrational resonance between various modes of vibration of the tetrahedral molecule. Quantum mechanical treatments of the effects are given in some detail.

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