Photofunctional molecular crystals
department or school: Science, Faculty of
department or school: Chemistry, Department of
data provider: DSpace
degree campus: UBCV
creator: Hean, Duane
issued: 2022-11-30T08:00:00Z
issued: 2021
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: Novel solid state photofunctional materials have been designed, and their structure-properties relationships are investigated. This thesis focuses on two distinct photofunctional properties: generating photomechanical motion in photoswitch-based crystals and ‘afterglow’ emission from organic alloy crystals and novel organic emitters. A novel hemithioindigo (HTI) photoswitch is functionalized with an anthracene group, and its photophysical properties are investigated in the solution and solid state. When irradiated with light, the photoswitch exclusively undergoes photoisomerization. In the crystalline state, E- isomer crystals isomerize and undergo a photosalient effect upon exposure to green light, while the Z- isomer undergoes a thermosalient event when heated. [2+2] Photodimerization is also employed to generate photomechanical motion in hemithioindigo photoswitch analogs. Hemithioindigo can undergo solid state reactions generating photoproducts not observable in solution. Three hemithioindigo photoswitch analogs are designed and used to elicit photomechanical motion in the crystalline state. Additionally, further mechanical motion is observed when previously irradiated crystals are heated. Crystallography and 1H NMR spectroscopy were used to provide insights into the mechanism of photomechanical motion. These proof-of-concept photomechanical responses in crystalline hemithioindigo photoswitches demonstrate their potential use as light-driven microactuators. The facile synthesis of HTIs enables tuning the photomechanical system based on the desired application. Solid state host-guest chemistry is employed to produce a series of seven organic alloys of two organic emitters with contrasting photophysical properties. One emitter has a long lifetime with ‘afterglow’ emission, while the other has a high photoluminescence efficiency. By carefully tuning the composition of the components between 30% - 100%, interesting photophysical properties emerge in addition to the …
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/80161
note: PHOTOFUNCTIONAL MOLECULAR CRYSTALS by Duane Hean M.Sc., The University of the Witwatersrand, 2015 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in THE FACULTY OF GRADUATE AND POSTDOCTORAL STUDIES (Chemistry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) November 2021 © Duane Hean, 2021 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Photofunctional Molecular Crystals submitted by Duane Hean in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Chemistry Examining Committee: Dr. Michael O. Wolf, Chemistry, UBC Supervisor Dr. Mark M. MacLachlan, Chemistry, UBC Supervisory Committee Member Dr. David M. Perrin, Chemistry, UBC University Examiner Dr. Gregory R. Dake, Chemistry, UBC University Examiner Additional Supervisory Committee Members: Dr. Mark Thachuk, Chemistry, UBC Supervisory Committee Member Dr. Parisa Mehrkhodavandi, Chemistry, UBC Supervisory Committee Member iii Abstract Novel solid state photofunctional materials have been designed, and their structure-properties relationships are investigated. This thesis focuses on two distinct photofunctional properties: generating photomechanical motion in photoswitch-based crystals and ‘afterglow’ emission from organic alloy crystals and novel organic emitters. A novel hemithioindigo (HTI) photoswitch is functionalized with an anthracene group, and its photophysical properties are investigated in the solution and solid state. When irradiated with light, the photoswitch exclusively undergoes photoisomerization. In the crystalline state, E- isomer crystals isomerize and undergo a photosalient effect upon exposure to green light, while the Z- isomer undergoes a thermosalient event when heated. [2+2] Photodimerization is also employed to generate photomechanical motion in hemithioindigo photoswitch analogs. Hemithioind…
has type: Thesis/Dissertation
date issued: 2022-05
is shown at: 10.14288/1.0403344
language: eng
degree discipline: Chemistry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
contributor: Wolf, Michael O.
type: Text
type: Still Image
identifier URI: http://hdl.handle.net/2429/80161