Degree Type

Dissertation

Date of Award

1986

Degree Name

Doctor of Philosophy

Department

Chemistry

Abstract

X-ray powder diffraction patterns of lead dioxide electrodes electrodeposited with Bi, As, or Tl were taken and analyzed via the Rietveld procedure. The doped oxides have a structure correspond- ing to a metal-substituted (beta)-PbO(,2). Unit cell volume of the Bi-doped oxides increases as Bi / Pb in the deposition solution increases. The diffraction patterns of the electrodeposited electrodes show strong preferred orientation and particle size broadening of the diffraction peaks. Variations of these two properties as a function of Bi / Pb seem to be closely correlated to the electrochemical oxidizing catalytic activities of the electrodes;A study of X-ray radiation damage on a molecular single crystal, Cr(CO)(,3)(C(,6)H(,6)), was carried out, in order to better understand its influence on crystallographic parameters. The crystal was irradiated with high flux of Mo radiation for nine different periods. After each irradiation, intensity data were collected and analyzed via least-squares refinement procedures. The results are lattice expansion, slight systematic variation of the positional parameters, and system- atic increases in the temperature factors. Apparently, the severe irradiation caused gradual loss of crystalline character, probably by weakening intermolecular packing forces. Little changes in intra- molecular geometry was noticed;The crystal structure determination of HB(pz)(,3) (CO)(,2)W (eta)('2)-CH- (SMe) (.)CF(,3)SO(,3), 1, confirmed the presence of the (eta)('2)-thiocarbene ligand, bonded to the tungsten through both the C and S atoms. In the phosphine adducts of 1, the phosphine adds to the carbene C preserving the same atomic connectivity as the carbene cation in the HB(pz)(,3))(CO)(,2)W((eta)('2)-CH(SMe) portion of the molecule. The reaction product of HB(pz)(,3) (CO)(,2)W(CS)('-) and Au(PR(,3))('+) (R = Ph or Me) has a structure with a W-Au bond bridged by semibridging CS and CO ligands;The Patterson superposition method was successfully applied to the determination of the crystal structures of LiMo(,8)O(,10) and 4PPh(,4) (.) O(,2)MoS(,2)FeS (,2) (.) 6H(,2)O, whose solutions had been greatly hindered by the existence of pseudo-symmetry. It is also demonstrated that ripples in Fourier maps due to series termination errors can aid structural solutions via Patterson superposition method.

DOI

https://doi.org/10.31274/rtd-180813-11897

Publisher

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

Copyright Owner

Sangsoo Kim

Language

en

Proquest ID

AAI8703720

File Format

application/pdf

File Size

176 pages

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