Date Thesis Awarded

4-2018

Document Type

Honors Thesis

Degree Name

Bachelors of Science (BS)

Department

Chemistry

Advisor

Robert D. Pike

Committee Members

Deborah C. Bebout

William R. McNamara

Marc T. Sher

Abstract

The reaction of copper(I) iodide (CuI) and alkyl pyridinium, quinolinium, 4,4ʹ-bipyridinium iodides, and butyl 3-substituted pyridinium (where the substitution = I, Br, Cl, OMe, and CN) salts ([RPy]+[I], [RQn]+[I], [R2(4,4ʹ-Bpy)]2+[I]2, and [Bu 3-PyX]+[I]) in alcohol with recrystallization in acetonitrile (MeCN) yields salts comprised of the arylinium cation and iodocuprate(I) anion. The iodocuprate(I) ions show a variety of stoichiometric and structural types, ranging from the 1-D chain structure {[CuI2]}n to the discrete cluster [Cu8I13]5–. A diverse range of anion types is particularly notable for [R2(4,4ʹ-Bpy)]2+, while [RPy]+, [RQn]+ and [Bu 3-PyX]+ are commonly paired with the 1-D chain {[Cu5I7]2–}n. Increasing the size of the organic cation alkyl chain appears to also increase the size of the iodocuprate anion, but only up to cations where R = Bu. Diffuse reflectance spectroscopy at 298 K was performed on the n-butyl – alkylated pyridinium, quinolinium, and substituted pyridinium salts (compounds 5, 9, and 18 – 22), and revealed that increasing the electron withdrawing capacity of the n-butyl arylinium system reduced the absorption edge of the iodocuprate salt. UV emission spectra at 298 and 78 K of compounds 5, 19, 20, and 22 showed two different emission peaks, one consistent with a cluster-centered halide to metal charge transfer (XMCT) and the other consistent with an intermolecular mixed halide/metal charge transfer to the organic cation. The emission intensity and emission wavelength of the mixed halide/metal to cation charge transfer (XMCCT) appears to depend on the organic cation substitution.

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