Document Type

Article

Publication Date

Fall 10-17-2017

Abstract

We report on the photoluminescence of {CuSCN(3-XPy) 2 } n crystals (X = Br, Cl; Py = pyridine). Laser excitation at 266 nm for CuSCN(3-BrPy) 2 at 78 K results in a decrease in the luminescence intensity with increasing irradiation time. Heating the sample to 298 K and re- cooling to 78 K results in recovery of the original luminescence intensity, hence manifesting an optical memory effect. Laser irradiation at longer or shorter wavelengths fails to produce a reduction in emission intensity. Interestingly, CuSCN(3-ClPy) 2 , despite being isomorphic, does not undergo emission intensity changes regardless of laser irradiation wavelength variation. Density Functional Theory (DFT) and Time Dependent DFT (TD-DFT) calculations were performed on an adjacent chain model to explore the photochemical change that occurs upon laser irradiation. The observed reduction in luminescence intensity is attributed to photo-induced electron transfer quenching in which Cu(I) is oxidized to a non-luminescent Cu(II) with capture of the halogen by a neighboring SCN ligand on the adjacent coordination polymer chain.

Journal Title

JOURNAL OF PHYSICAL CHEMISTRY C

DOI

10.1021/acs.jpcc.7b06871

Volume

121

Issue

45

Journal Article URL

https://pubs.acs.org/doi/10.1021/acs.jpcc.7b06871

First Page

25430

Publisher Statement

This document is the unedited author's version of a Submitted Work that was subsequently accepted for publication in the Journal of Physical Chemistry C, copyright © American Chemical Society after peer review. To access the final edited and published work see 10.1021/acs.jpcc.7b06871.

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