Undergraduate Honors Thesis Projects

Date of Award

4-15-2015

Document Type

Honors Paper

Degree Name

Chemistry-BS

Department

Chemistry

Advisor

Dean H. Johnston, Ph.D.

First Committee Member

Dean H. Johnston, Ph.D.

Second Committee Member

Robin E. Grote, Ph.D.

Third Committee Member

Karen Steigman, Ph.D.

Keywords

Metal Halide Cluster, Metal Organic Framework, Ionic Liquid, Imidazolium

Subject Categories

Inorganic Chemistry

Abstract

This study investigated two different schemes of imidazolium and carboxylate salts to assess their use in preparing metal halide cluster networks. The first scheme used salts of 1-ethyl-3-methylimidazolium [EMIM]+ and 1-butyl-3-methylimidazolium [BMIM]+ as the cations and benzene-1,3,5-tricarboxylate [TMA]-, benzene 1,3-dicarboxylate [IPA]-, and benzene-1,4-dicarboxylate [TPA]- as the anions. The anions are commonly used in porous inorganic materials synthesis, as the size of the cation has been shown to often impact the final structure of the materials. The anions are common bridging ligands used to create network solids. The second scheme used 1,3-dimethylimidazolium triflate [DMIM]+ [OTf]- and sodium and tetrabutylammonium salts of the carboxylate linkers. This triflate anion of this second scheme was chosen because it does not coordinate as strongly to the clusters as carboxylate ligands.

The first scheme was found to be unsuitable because the synthetic procedure resulted in media that contained small amounts of water and other contaminants that would degrade the cluster. The ionic liquid used in the second scheme was prepared using a synthetic procedure that avoided the same contamination. DSC also revealed it had suitable melting point and liquid range for this application. Successful dissolution of the clusters in the ionic liquid was found to be dependent upon the terminal ligand on the cluster matching the anion of the ionic liquid. Similarly, dissolution of the carboxylate salt in the ionic liquid was dependent on the lattice energy of the cation and carboxylate anion. Upon dissolution of the cluster and tetrabutylammonium carboxylate in [DMIM]+[OTf]-, the solution undergoes an intense color change from light yellow orange to deep red, but no product was able to be isolated.

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