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

Citation

Anderson, Thomas Foxen (1936) Ein Neues Drehprismenverfahren zur Photographischen Ermittlung der Dispersion, and Applications of Raman Spectra to Chemistry. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/07vb-w743. https://resolver.caltech.edu/CaltechTHESIS:11012024-203800967

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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