Southern Methodist University SMU Scholar Chemistry Theses and Dissertations Chemistry Fall 12-21-2019 Hypervalent Iodine Compounds with Carboxylate and Tetrazolate Ligands Avichal Vaish Southern Methodist University, [email protected] Follow this and additional works at: https://scholar.smu.edu/hum_sci_chemistry_etds Part of the Analytical Chemistry Commons, Inorganic Chemistry Commons, Materials Chemistry Commons, Organic Chemistry Commons, and the Polymer Chemistry Commons Recommended Citation Vaish, Avichal, "Hypervalent Iodine Compounds with Carboxylate and Tetrazolate Ligands" (2019). Chemistry Theses and Dissertations. 15. https://scholar.smu.edu/hum_sci_chemistry_etds/15 This Dissertation is brought to you for free and open access by the Chemistry at SMU Scholar. It has been accepted for inclusion in Chemistry Theses and Dissertations by an authorized administrator of SMU Scholar. For more information, please visit http://digitalrepository.smu.edu. HYPERVALENT IODINE COMPOUNDS WITH CARBOXYLATE AND TETRAZOLATE LIGANDS Approved by: ____________________________________ Advisor: Dr. Nicolay V. Tsarevsky Associate Professor of Chemistry ____________________________________ Dr. Isaac Garcia-Bosch Assistant Professor of Chemistry ____________________________________ Dr. David Y. Son Professor of Chemistry ____________________________________ Dr. Brian D. Zoltowski Associate Professor of Chemistry ____________________________________ Dr. Mihaela C. Stefan Professor of Chemistry (UT Dallas) HYPERVALENT IODINE COMPOUNDS WITH CARBOXYLATE AND TETRAZOLATE LIGANDS A Dissertation Presented to the Graduate Faculty of Dedman College Southern Methodist University in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy with a Major in Chemistry by Avichal Vaish B.S. – M.S., Chemical Sciences, Indian Institute of Science Education and Research, Kolkata December 21st, 2019 Copyright © 2019 Avichal Vaish All Rights Reserved ACKNOWLEDGEMENTS The experience of graduate school provided me with the widest range of personal and professional experience. Although, this journey was full of ups and downs, it taught me valuable lessons and certainly prepared me for the life to come. I could not have achieved my goals without the support of several people, and I would now like to thank them and recognize their support with utmost sincerity. First of all, I would like to express my deepest appreciation to my research advisor, Dr. Nicolay V. Tsarevsky, for giving me an opportunity to pursue a Ph.D. degree under his guidance. I have always been encouraged and supported by him to explore new techniques and ideas. He has been essential in my growth as a scientist by allowing me to express my creativity and giving me the freedom to solve the challenges that I encountered in my research in my own way. I am grateful that he encouraged me to work outside my comfort zone which made me a better and confident chemist. I am extremely grateful to Dr. Priyadarsi De, my master’s thesis advisor, who introduced me to polymer chemistry and gave me an opportunity to join his lab early in my career which paved a path for me to pursue Ph. D. in chemistry. I would like to thank all my fellow present and past group members, specially Rajesh and Yakun, for frequent discussion related to my research. I would also like to thank National Science Foundation and Department of Chemistry (SMU) for financial support to conduct my research. SMU’s Department of Chemistry provided excellent study and research atmosphere. I am extremely grateful to Dr. Michael Lattman for guiding me through the course work. Particularly, I would like to give my sincere thanks to my committee members, Dr. Mihaela C. Stefan (UT Dallas), Dr. David Son, Dr. Isaac Garcia-Bosch, and Dr. Brian D. Zoltowski for their precious time and assistance in reviewing, criticizing, and improving my work. There were several occasions where the required instrument for my research was not available at SMU. Therefore, I reached out to the neighboring universities to find an instrument. I would like to thank Dr. Danieli Rodrigues and Mr. Danyal Siddiqui from University of Texas at Dallas for providing help with the rheological measurements. I am also grateful to Mr. Meciej Kukula and Dr. Eric Weaver from University of Texas at Arlington for trusting me with the LCMS-IT-ToF and MALDI-ToF instrument, respectively. I am grateful to Dr. Alan Humason for clarifying all my doubts and helping me with instruments. I am grateful to Dr. Isaac Garcia Bosch for allowing me to use his cyclic voltammeter and glove box. Thanks to Khashayar and Rachel for teaching me to operate the cyclic voltammeter and glove box. I would also like to thank Dr. Alexander Lippert for allowing me to use his ESI- MS instrument and thanks to Luke for running the samples for me. I am thankful to Dr. Tomče Runčevski, John, and Christina for helping me with the TGA, DSC, and powder XRD measurements. Finally, and most importantly, I would like to thank my family and friends, especially my parents Vijai Kumar Vaish & Sarla Vaish, my brother Aviral Vaish, my sister Virla Vaish, and my brother-in-law Akhil Mudgal for providing their unwavering support and unceasing love they have given me while I have pursued my education for which I will always be in debt to them. A special thanks to Sumanjani Vinnakota for helping me throughout my career and always motivating and steering me in the correct direction. I am grateful to my friends Stephen Budy, Caleb Bunton, Weiwei An, Jian Cao, Ashutosh Pudasaini, Sandra Plunkett Pudasaini, Bibek Ranjan Samanta, Chiranjit Mitra, Saswata Roy, Harsh Vardhan Gaur, Krupal Desai, and Nikhil Katiyar for their unconditional support. Reproduced by permission of the John Wiley & Sons, Inc. (Hypervalent Iodine Compounds in Polymer Science and Technology. In Main Group Strategies towards Functional Hybrid Materials eds T. Baumgartner and F. Jäkle, 10.1002/9781119235941.ch19), the Royal Society of Chemistry (Polym. Chem., 2019, 10, 3943-3950, 10.1039/C9PY00664H), the American Chemical Society (J. Org. Chem., 2018, 83, 12496-12506, 10.1021/acs.joc.8b01715), and the Elsevier Publishing Company (Tetrahedron Lett., 2019, 60, 150995, 10.1016/j.tetlet.2019.150995). Avichal Vaish B.S.-M.S. Dual Degree, Chemical Sciences, Indian Institute of Science Education and Research, Kolkata Hypervalent Iodine Compounds with Carboxylate and Tetrazolate Ligands Adviser: Professor Nicolay V. Tsarevsky Doctor of Philosophy conferred December 21, 2019 Dissertation completed October 29, 2019 In modern organic chemistry, hypervalent (HV) iodine(III) compounds are frequently used as oxidizing agents but application of λ3-iodanes in polymer and material chemistry is still underexplored. This dissertation describes the preparation of dynamic and self-healing materials by employing ligand exchange reactions involving HV iodine(III) compounds of the type ArIL2 (Ar = Aryl, L = ligand, e.g., carboxylate or (pseudo)halide). These compounds can undergo ligand - exchange reactions in presence of nucleophiles (Nu ) to form ArINu2. Diacetoxyiodo benzene was successfully employed as a crosslinker to prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore, advantage was taken of the ability of diacetoxyiodo benzene to generate radicals upon UV light irradiation in order to convert the dynamic crosslinked structures to permanent (set) networks. Star polymers were prepared by mixing block copolymers Sty/MMA and AA with diacetoxyiodo benzene solution. The star polymers were characterized by dynamic light scattering and diffusion ordered NMR spectroscopy. Besides that, oligomeric and µ-oxo- HV iodine(III) compounds with two I-N bonds, containing 5-substituted tetrazoles as the ligands PhI(N4CR)2 (R = C6H5, and 4-CH3C6H4) were synthesized using PhIO. The crystal structure of one representative compound (an oligomer with VII three I atoms in the backbone and 5-phenyltetrazole end groups) was solved and refined from synchrotron powder X-ray diffraction. The novel compounds were characterized by cyclic voltammetry and were found to be strong oxidants. An attempt was made to prepare tetrazole based polymer networks. After synthesizing tetrazole containing oligomeric HV iodine(III) compounds, N-heterocycle-stabilized pseudocyclic λ3-iodane with tetrazole as the stabilizing group was synthesized and its thermal stability and redox activity were studied. The oxidative power of the polyvalent iodine compound with a tetrazole ligand was demonstrated by conducting oxidation of thioanisole to sulfoxide and dimerization of thiobenzamide to 3,5-diphenyl-1,2,4-thiadiazole. VIII TABLE OF CONTENTS LIST OF FIGURES ............................................................................................................ XIII LIST OF SCHEMES ........................................................................................................ XVIII LIST OF TABLES .............................................................................................................. XXI LIST OF ABBREVIATIONS ............................................................................................ XXII CHAPTER I INTRODUCTION ..............................................................................................1 I.1 Introduction to Polymer Chemistry .....................................................................................1 I.1.1 Introduction and Historical Development .....................................................................1