ORCID ID

0000-0002-3198-1986

Date Awarded

Fall 2016

Document Type

Thesis

Degree Name

Master of Science (M.Sc.)

Department

Chemistry

Advisor

Robert D Pike

Committee Member

Deborah C Bebout

Committee Member

John C Poutsma

Abstract

A series of CuSCN compounds were synthesized. Ligands included the alkyl sulfides methyl sulfide (Me2S), ethyl sulfide (Et2S), isopropyl sulfide (Pri2S) and tetrahydrothiophene (THT); diimine ligands pyrazine (Pyz), 2,3-dimethylpyrazine (2,3- Me2Pyz), 2,5-dimethylpyrazine (2,5-Me2Pyz), 2-aminopyrazine (2-NH2Pyz) and 2- methoxypyrazine (2-MeOPyz); two-ring diimines quinoxaline (Qox), quinazoline (Qnz), phthalazine (Ptz); and 3-halopyridines 3-chloropyridine (3-ClPy), 3-bromopyridine (3- BrPy), 3-iodopyridine (3-IPy). Crystal structures were solved for twelve products. With the exception of one Cu(II) compound, all could be classified in the common motifs of chains, ladders or sheets. Alkyl sulfides formed either 1:2 (CuSCN)L2 1-D chains (L = Me2S, 1a and THT, 4) or 1:1 (CuSCN)L2 1-D ladders (L = Et2S, 2 and Pri2S, 3) when reacted with CuSCN. New compounds of CuSCN with diimine ligands included two 2:1 (CuSCN)2LL 2-D bridged ladders (LL = Qox, 5 and 2-NH2Pyz, 8), two (CuSCN)L 1:1 2-D sheets (L = Qnz, 6 and 2-MeOPyz, 9) and one 1:1 (CuSCN)LL 2-D sheet (Ptz, 7). Structures of the known 1:2 (CuSCN)L2 compounds, where L = 3-ClPy (15a) or 3-BrPy (16) were solved as 1-D chains. Optical memory experiments sought to rapidly and significantly reduce the peak intensity in the ultraviolet/visible (UV/Vis) emission spectra of the synthesized compounds as a means of storing binary information. Fully emissive states were assigned as “unwritten,” while states with reduced emission were assigned as “written.” Samples were exposed to a high-energy tunable UV laser at 80 K for five minute intervals in order to affect emission intensities. Recovery capabilities were assessed by warming the samples to 298 K, allowing them to reach thermal equilibrium, and cooling them to 80 K before obtaining final scan. The known compounds (CuSCN)2LL, where LL= 2,3- dimethylpyrazine (2,3-Me2Pyz, 11), 2,5-dimethylpyrazine (2,5-Me2Pyz, 12) demonstrated reduced emission after irradiation, but suffered from fatigue after only one write/read/erase cycle. Compound 16 proved the most promising, displaying both significant emission depletion and complete recovery of initial intensity after three cycles. The x-ray crystal structure of 16 indicates numerous close carbon-bromine and sulfur- bromine interactions. Combined with computational calculations indicating an elongation of the pyridine C-Br bond in the most probable excited state, it is plausible that structural features play a role in the optical memory behavior of this compound.

DOI

http://doi.org/10.21220/S2K01Q

Rights

© The Author

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