Exploring the Reactivity of Phosphonium Salts with Group 14 Halides
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University of Windsor Scholarship at UWindsor Electronic Theses and Dissertations Theses, Dissertations, and Major Papers 9-26-2018 Towards Putting the ‘P’ in Perovskite: Exploring the Reactivity of Phosphonium Salts with Group 14 Halides Emily Helen Omahen University of Windsor Follow this and additional works at: https://scholar.uwindsor.ca/etd Recommended Citation Omahen, Emily Helen, "Towards Putting the ‘P’ in Perovskite: Exploring the Reactivity of Phosphonium Salts with Group 14 Halides" (2018). Electronic Theses and Dissertations. 7552. https://scholar.uwindsor.ca/etd/7552 This online database contains the full-text of PhD dissertations and Masters’ theses of University of Windsor students from 1954 forward. These documents are made available for personal study and research purposes only, in accordance with the Canadian Copyright Act and the Creative Commons license—CC BY-NC-ND (Attribution, Non-Commercial, No Derivative Works). 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Towards Putting the ‘P’ in Perovskite: Exploring the Reactivity of Phosphonium Salts with Group 14 Halides By Emily Helen Omahen A Thesis Submitted to the Faculty of Graduate Studies through the Department of Chemistry and Biochemistry in Partial Fulfillment of the Requirements for the Degree of Master of Science at the University of Windsor Windsor, Ontario, Canada 2018 © 2018 Emily Helen Omahen Towards Putting the ‘P’ in Perovskite: Exploring the Reactivity of Phosphonium Salts with Group 14 Halides by Emily Helen Omahen APPROVED BY: ______________________________________________ C. Weisener Great Lakes Institute for Environmental Research ______________________________________________ J. Rawson Department of Chemistry & Biochemistry ______________________________________________ C. Macdonald, Advisor Department of Chemistry & Biochemistry September 18th, 2018 DECLARATION OF ORIGINALITY I hereby certify that I am the sole author of this thesis and that no part of this thesis has been published or submitted for publication. I certify that, to the best of my knowledge, my thesis does not infringe upon anyone’s copyright nor violate any proprietary rights and that any ideas, techniques, quotations, or any other material from the work of other people included in my thesis, published or otherwise, are fully acknowledged in accordance with the standard referencing practices. Furthermore, to the extent that I have included copyrighted material that surpasses the bounds of fair dealing within the meaning of the Canada Copyright Act, I certify that I have obtained a written permission from the copyright owner(s) to include such material(s) in my thesis and have included copies of such copyright clearances to my appendix. I declare that this is a true copy of my thesis, including any final revisions, as approved by my thesis committee and the Graduate Studies office, and that this thesis has not been submitted for a higher degree to any other University or Institution. iii ABSTRACT Inorganic/organic hybrid perovskites have emerged as synthetic materials that exhibit light-harvesting properties. Although perovskites with alkylammonium cations have been previously reported, a perovskite family with phosphonium cations has not been investigated. Firstly, a library of phosphonium salts was made with the intention of further reaction with the group 14 halides towards creating a perovskite crystal. The composition of these salts were elucidated via NMR spectroscopy, and the crystal structures of three of the phosphonium salts were determined. The phosphonium iodide salts were then reacted with the lead, tin, and germanium iodides and bromides to discover if variant perovskitic structures are obtained. The reaction of lead(II) iodide with various phosphonium salts produced - a charge-balanced network of PbI3 fragments connecting in a face-sharing octahedral motif. These phosphonium-templated iodoplumbates were found to possess semi-conducting properties, as suggested by the results of UV-Vis and their high thermal stability was confirmed by TGA experiments. Three novel crystal structures were isolated from reaction of phosphonium salts with tin(II) and tin(IV) iodide, each of them producing an iodostannate anion with a unique geometry. In a reaction with SnI4 an unpredictable oxidation of starting material produced a potentially Lewis acidic tin(IV) cation. Finally, the reaction of phosphonium salts with germanium(II) halides produced charge-balanced compounds with an ABX3 general formula that did not crystallize in a perovskitic manner. Germanium(IV) iodide formed a series of co-crystals when reacted with the phosphonium iodide salts. These species were found to form Ge-I‧‧‧‧I halogen-bonding interactions. iv ACKNOWLEDGEMENTS Some of the best journeys we take in life are often the ones that are unexpected. I never planned on going to graduate school, but after the conclusion of my undergraduate degree I had a gut feeling that it was something I should pursue. I am certainly glad I chose to take this path, as I have grown a lot over the past two years as a chemist and a person. It wasn’t easy to juggle graduate studies, teaching, and being an elite athlete and I would like to thank all of the people who supported me on this journey and made the completion of this degree possible. Firstly, I would like to thank my supervisor, Dr. Chuck Macdonald, for his support and guidance throughout my graduate studies as well as during my undergraduate degree. I joined the Macdonald Research Group as an Outstanding Scholar in my second year, and ever since then Chuck has been instrumental in my development as a chemist and moreover as a researcher. Not only did he answer the questions I had with regards to my projects, he also taught me how to ask the questions that needed an answer, and ultimately that is what research is about. I would also like to thank my other committee members, Dr. Weisener and Dr. Rawson, for taking the time to read this thesis. I would like to thank Justin Binder and Dr. Stephanie Kosnik for taking me under their wings when I was an undergrad and being outstanding mentors. Not only did they train me in all the areas I needed to be a good chemist, but they were always available to troubleshoot research problems with me and find a solution. Thank you to Ala’aeddeen Swidan and Brad Jacobs for being there to bounce ideas off, in both v chemistry and in life, and for their constant life chats. I’d also like to thank the other members of the Macdonald Group, past and present, for all the laughs that we have had in the office, most of the time at the expense of each other. Thanks to Max, Louae, and Balakey for being the most comical group of 410 students around. I’d also like to thank the friends I have made during my time as part of the department. To Nadia Stephaniuk, thank you for being the best roommate I could have asked for. You have always brought positive energy to any situation, even when I needed to rant. To Dominique Leckie, thank you for being someone I can depend on to talk about anything from chemistry to life choices. To Lara Watanabe, thank you for also being someone that I can chat with, vent to about thesis things, and talk about the crazy East Coast weather with. To Adit and Dan, thanks for helping to make my first chemistry conference such a lit time. These people have truly made my experience in graduate school one to remember. There are also so many people outside the department that I’d like to thank. Last May, I was seriously considering dropping out of the program, and without these people I would not have been able to persevere and write this thesis. To my coach, Brett Lumley, thank you for your guidance on and off the track throughout the course of my degree. Thank you for being so accommodating when I had deadlines or experiments to run, and helping me balance being an elite athlete with being a graduate student. Not only have you made me a better athlete, but you have also made me a better person. To Ben Warnock, who is pretty much my big brother, thank you for constantly pushing me to achieve my goals and being a great inspiration for overcoming adversity. To Mayce Mirza, Joanne Yu, Matthew vi McLaughlin, and Leslie Hernandez, thank you for never allowing me to give up on my studies and, in a broader sense, my overall life goals. Each of you has inspired me in your own way to keep “reaching for the stars” (as cheesy as that sounds) and to keep going after my passion. You are all success stories in your own way and I feel privileged that I was able to watch each of you achieve your goals. I hope one day I may be as successful as you. I would also like to thank my loving and supportive parents and sister. Although I may not always show it, I truly appreciate all the times you let me take the car to go to lab, all the times you let me pack the leftovers for lunch, and for the constant nagging that pushed me to finish my thesis. Thank you for inspiring me to never give up on my dreams. Finally, I would like to thank my amazing boyfriend, Randall Beardy, who is literally my beacon of sunshine. Thank you for your constant optimism and wisdom. You have supported me from the beginning of this Master’s degree and your belief in me has never wavered.