Degree Type

Dissertation

Date of Award

1984

Degree Name

Doctor of Philosophy

Department

Chemistry

Abstract

The polarized crystal spectra for twenty compounds of the type M(A)(,2,4)MX(,4), where M = Pt or Pd; A = NH(,3), CH(,3)NH(,2), or ethylenediamine; X = Cl or Br, are reported for both 6K and room temperature. Crystals of seventeen of the compounds were indexed; from the unit cells obtained, the metal-metal spacings, d(M-M), were calculated. The relationships of the transitions observed in the spectra and the metal-metal spacings are discussed;Assignment of the absorptions to electronic states are made. The temperature dependence of the peaks in the spectra suggest that the ('1)B(,1g) (<---) ('1)A(,1g) transition undergoes the greatest shift in energy as d(M-M) is decreased. For each series of salts--PdCl(,4)('2-), PdBr(,4)('2-), PtCl(,4)('2-), and PtBr(,4)('2-)--the ('1)B(,1g) (<---) ('1)A(,1g) transition was determined to have red-shifted from the energy of the ('1)E(,g) (<---) ('1)A(,1g) transition in the potassium salt;Several allowed transitions were observed in the spectra. The moderately weak ((epsilon) (TURNEQ) 600 cm('-1)M('-1)) peaks in z-polarization for Pt(en)(,2)PdCl(,4), Pt(CH(,3)NH(,2))(,4)PdCl(,4), and Pt(NH(,3))(,4)PdCl(,4) were assigned to the interionic electron-transfer, ('1)A(,2u) (<---) ('1)A(,1g) (b(,1u)cation (<---) b(,2g)anion). The sharp bands between 33,600 cm('-1) and 31,900 cm('-1) in the x,y-polarized spectra of Pt(en)(,2)PtCl(,4), Pt(CH(,3)NH(,2))(,4)PtCl(,4) and Pt(NH(,3))(,4)PtCl(,4) at 6K were tentatively assigned to a second interionic electron transfer transition, p(,z)cation (<---) d(,xz,yz)anion;The intensities of vibrational structure observed in several bands are reported and discussed. A rationalization of the intensities, based on the spatial restriction of the metal-halogen bending vibration, (nu)(,7), in the excited state, is proposed;An attempt to solve the crystal structure of Pt(en)(,2)PdCl(,4) by single-crystal x-ray diffraction is reported, and important values tabulated.

DOI

https://doi.org/10.31274/rtd-180813-5525

Publisher

Digital Repository @ Iowa State University, http://lib.dr.iastate.edu/

Copyright Owner

Michael Lee Rodgers

Language

en

Proquest ID

AAI8423737

File Format

application/pdf

File Size

184 pages

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