Degree Type

Dissertation

Date of Award

1990

Degree Name

Doctor of Philosophy

Department

Chemistry

First Advisor

John D. Corbett

Abstract

The compositional variety of zirconium chloride cluster phases, has been expanded by the synthesis and characterization of over 30 new compounds in nine distinctive structure types. Similar to known zirconium chloride clusters that are centered by small main-group elements (H,Be-N), all of the new cluster compounds have discrete (Zr[subscript]6Cl[superscript] i[subscript]12Z) Cl[superscript] a[subscript]6 (Cl[superscript] i = edge-bridging, inner Cl, Cl[superscript] a = terminal, outer Cl; Z = H, Be-C, Mn-Ni) units as the basic building blocks, and their cluster electron counts are at or close to the optimal values. However, incorporation of transition metals (Mn-Ni) into the cluster cores and the accommodation of alkaline-earth-metal or rare-earth-metal cations into the lattice have provided many new structural possibilities. The characterization of Ba[subscript]2Zr[subscript]6Cl[subscript]17B with a new structure type completes the (Zr[subscript]6Cl[superscript] i[subscript]12Z) Cl[superscript] a[subscript] n series in which n varies from zero to six. The discovery of Cs[subscript]3(ZrCl[subscript]5)Zr[subscript]6Cl[subscript]15Mn also provides a unique structure type with many novel features. The synthesis and characterization of the Li[subscript] xZr[subscript]6Cl[subscript]15M (M = Mn-Ni, x = 0, 1, 2) series with the Nb[subscript]6F[subscript]15 structure and the discovery of KZr[subscript]6Cl[subscript]15Fe with a super-structure of CsNb[subscript]6Cl[subscript]15 type reveals correlations between structure and the size of the cluster core. Systematic studies on the Zr[subscript]6Cl[subscript]18Z compounds in five structure types, namely Li[subscript]6Zr[subscript]6Cl[subscript]18H, K[subscript]4Nb[subscript]6Cl[subscript]18, K[subscript]2ZrCl[subscript]6· Zr[subscript]6Cl[subscript]12H, CsLuNb[subscript]6Cl[subscript]18, and Ba[subscript]3Zr[subscript]6Cl[subscript]18Be, and on the MZr[subscript]6Cl[subscript]14Mn family (M = alkali metal) also demonstrate that the changes in charge, size and occupancies of the counteractions may induce intriguing structure modifications;Solid state NMR with [superscript]7Li was employed in combination with X-ray diffraction techniques to locate Li atoms in the lattice of three cluster phases, Li[subscript]6Zr[subscript]6Cl[subscript]18H, Li[subscript]2Zr[subscript]6Cl[subscript]15Mn and LiZr[subscript]6Cl[subscript]14Mn.

DOI

https://doi.org/10.31274/rtd-180813-12315

Publisher

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

Copyright Owner

Jie Zhang

Language

en

Proquest ID

AAI9110584

File Format

application/pdf

File Size

244 pages

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