Degree Type

Dissertation

Date of Award

1990

Degree Name

Doctor of Philosophy

Department

Chemistry

First Advisor

John D. Corbett

Abstract

Fifteen centered zirconium chloride cluster phases with five different interstitial atoms (Z = H, Be, B, C, Fe) were successfully derivatized in solution by replacing the six terminal or intercluster bridging chlorine ligands of the starting (Zr[subscript]6Cl[subscript]12Z)Cl[subscript]6 type clusters with a variety of neutral (RNH[subscript]2, R[subscript]3P) or charged (Cl[superscript]-, Br[superscript]-) ligands. Acetonitrile was the only solvent used successfully for derivatization reactions;Reactions of solid KZr[subscript]6Cl[subscript]15C, Rb[subscript]5Zr[subscript]6Cl[subscript]18B, K[subscript]3Zr[subscript]6Cl[subscript]15Be, Na[subscript]4Zr[subscript]6Cl[subscript]16Be and KZr[subscript]6Cl[subscript]15Fe with X[superscript]- (X = Cl,Br) led to the isolation and X-ray crystallographic analyses of a series of eleven compounds containing ((Zr[subscript]6Cl[subscript]12Z)Cl[subscript]3X[subscript]3][superscript]4- clusters (Z = Be, B, C, for X = Cl; Z = Fe for X = Cl, Br), many with Et[subscript]4Y[superscript]+ (Y = N,P) or Ph[subscript]4P[superscript]+ cations. Oxidation of some of the normal 14-electron clusters centered by main group elements to the 13- and 12-electron clusters by the solvent was observed. While 13- and 14-electron clusters are known for solid state precursors, the 12-electron (Zr[subscript]6Cl[subscript]18Be)[superscript]4- cluster has been obtained exclusively by the non-aqueous solution route. The bond distances within the 13- and 12-electron clusters reflect the loss of one and two electrons from the metal-metal bonding HOMO (t[subscript] 2g[superscript]6) with an average increase in Zr-Zr bond lengths of 0.05A and 0.10A, respectively, relative to the distances in the solid state phases;Cyclovoltammograms of a (Zr[subscript]6Cl[subscript]18B)[superscript] n- solution in acetonitrile indicate the presence of not only 14-, 13-, and 12-electron clusters, which have already been isolated with different interstitial atoms, but also of a possible 15-electron cluster;Primary amines and Et[subscript]3P were used for the successful derivatization of K[subscript]3Zr[subscript]6Cl[subscript]15Be, Na[subscript]4Zr[subscript]6Cl[subscript]16Be and Li[subscript]6Zr[subscript]6Cl[subscript]18H in acetonitrile and subsequent isolation and X-ray crystallographic analysis of (Zr[subscript]6Cl[subscript]12Z)(RNH[subscript]2)[subscript]6·CH[subscript]3CN (Z = Be, R = Et, i-Pr; Z = H, R = Et) and (Zr[subscript]6Cl[subscript]12Be)(Et[subscript]3P)[subscript]6. The average bond lengths within these clusters show that the change from Cl[superscript]- exo ligands in the original phases to the neutral organic bases in the derivatives essentially does not affect the bond distances within the (Zr[subscript]6Cl[subscript]12Z) cluster core. ftn*This research was supported by the National Science Foundation - Solid State Chemistry - Grants DMR - 8318616 and - 8902954.

DOI

https://doi.org/10.31274/rtd-180813-12619

Publisher

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

Copyright Owner

Friedhelm Rogel

Language

en

Proquest ID

AAI9100499

File Format

application/pdf

File Size

195 pages

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