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Ferrocenes and Isoindolines As Reagents for Redox Flow Battery Electrolytes and Moieties in Chromophores, Chelates, and Macrocycles

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@ 2021 Briana R. Schrage ALL RIGHTS RESERVED FERROCENES AND ISOINDOLINES AS REAGENTS FOR REDOX FLOW BATTERY ELECTROLYTES AND MOIETIES IN CHROMOPHORES, CHELATES, AND MACROCYCLES A Dissertation Presented to The Graduate Faculty of The University of Akron In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy Briana R. Schrage August, 2021 FERROCENES AND ISOINDOLINES AS REAGENTS FOR REDOX FLOW BATTERY ELECTROLYTES AND MOIETIES IN CHROMOPHORES, CHELATES, AND MACROCYCLES Briana R. Schrage Dissertation Approved: Accepted: ______________________________ ___________________________ Advisor Department Chair Dr. Christopher J. Ziegler Dr. Christopher J. Ziegler ______________________________ ___________________________ Committee Member Dean of the College Dr. Aliaksei Boika Dr. Joseph Urgo ______________________________ ___________________________ Committee Member Dean of the Graduate School Dr. Claire A. Tessier Dr. Marnie M. Saunders ______________________________ ___________________________ Committee Member Date Dr. Yi Pang ______________________________ Committee Member Dr. Junpeng Wang iii ABSTRACT Although rechargeable battery technology has been around as early as the 1800s, redox flow battery (RFB) technology has a little under five decades of research. The most common and well-studied system is the all-vanadium RFB. To this day there is still no perfect RFB design and many batteries suffer from membrane crossover due to corrosive solvents or electroactive materials. Additionally, the cost of some electrolyte components are expensive, and the materials themselves may be toxic. Recent studies have investigated the use of metallocenes as potential RFB components, particularly ferrocene. The ferrocene scaffold is easily modified and this organometallic unit undergoes a highly reversible redox reaction. Introducing water solubilizing groups to metallocenes can allow for these materials to be used in aqueous RFB devices. The second and third chapters of this dissertation investigate the electrochemistry of ferrocene-based compounds, and a practical application involving one of these compounds was investigated in a RFB cell. In chapter II, a series of four all-ferrocene salts were synthesized comprising of a (ferrocenemethyl)trimethylammonium cation and either carboxylate or sulfonate ferrocene anion. Cyclic voltammograms in water, propylene carbonate (PC), and DMF result in different potentials of the ions in solution. Chapter III investigates the 1,1’-bis(sulfonate)ferrocene dianion disodium salt as a catholye species in a iv battery cell paired with anthraquinone-2,7-disulfonic acid disodium salt as the anolyte. The RFB experiments were performed using aqueous solvent in both neutral pH conditions with 1 M NaNO3, as well as acidic pH conditions using either 0.5 M H2SO4 or 2 M acetate buffer. The second half of this dissertation investigates chelates, chromophores and macrocycles that use 1,3-diiminoisoindoline (DII) as a starting reagent. Since Elvidge and Linstead discovered DII in 1952, they quickly made progress generating new chelates and macrocycles with this compound. Elvidge and Linstead’s discovery of chelates called bis(arylimino)isoindoline (BAI) ligands arise from the condensation of DII with aryl amines, and the ligands typically bind to metals in a meridional coordination mode rather than a facial mode. Chapter IV investigates a rare example where three BAI ligands bind to Re(CO)3 in a facial coordination mode. The ligands distort from planarity and the complexes exhibit MLCT bands in the UV-visible spectra. Chapter V of this dissertation revisits the Knoevenagel condensation reaction between DII and ethylcyanoacetate, first carried out by Elvidge and Linstead, and extends it to other organic acids. Four 1,3-diylideneisoindolines were synthesized, yielding brightly colored chromophores. The DFT calculations reveal that that the HOMO energies vary depending on the alkene substituent and possess a significant degree of alkene character. In addition to BAI chelates, Elvidge and Linstead synthesized macrocyclic systems called hemiporphyrazines, where the condensation reaction between DII and 2,6-diaminopyridine, yields a 20π electron non-aromatic system. Chapter VI of this dissertation studies the synthesis of a hexameric hemiporphyrazine resulting from the condensation of DII with a dimeric form of 2,6-diaminopyridine called bis(6-amino-2-pyridyl)amine. The expanded system does not possess any aromaticity, like hemiporphyrazine, and the X-ray crystal structure of the ligand shows two inverted rings in the backbone. The last two chapters of this dissertation examine the structure and electronics of new phthalocyanine and subphthalocyanine anologs called biliazine and subbiliazine. Along with BAIs, under certain circumstances singly substituted DII chelates can be generated. These chelates are called semihemiporphyrazines and a new semihemiporphyrazine was generated with DII and 3-aminopyrazole in chapter VII. Subsequent dimerization of this chelate results in a phthalocyanine anolog called biliazine, where the meso position of the macrocycle is closed by a hydrogen bond. This reaction was carried out in the presence of Zn, Cu, and Co acetate metal templates, and the free base ligand was also isolated. The ring contracted variants of these systems are presented in chapter VIII of this dissertation. Two BAI chelates with aminopyrazole and aminoindazole were synthesized and reacted with BF3 to yield a ring contracted variant of biliazine. These complexes called subbiliazines have a similar bowl-shape to subphthalocyanine. Reaction of the ligands under non-anhydrous conditions results in hydrolysis products, including the formation of a new dibenzo aza- BODIPY analog. vi DEDICATION To my father, Dr. Dean Schrage ACKNOWLEDGEMENT I would first like to thank my advisor Dr. Christopher J. Ziegler. Words cannot express my gratitude for all of his guidance and help. He has formed me into the scientist I am today, and I could not have accomplished as much as I did without his direction, and broad scientific knowledge. His strong work ethic, ability to navigate through problems, teach others, and design unique projects is truly an inspiration. I will always cherish his teachings and his mentoring will stay with me forever. I would like to thank Dr. Aliaksei Boika for all of his help with the redox flow battery project. His involvement has been incredibly useful and much appreciated. I would also like to thank Dr. Viktor Nemykin, who has been patient with me and always answers my questions. I am grateful for his involvement in the computational analysis of my molecules. I would also like to thank Dr. Richard Herrick, who has provided valuable input on projects. Thank you to the members of my committee: Dr. Claire Tessier, Dr. Yi Pang, Dr. Aliaksei Boika, and Dr. Junpeng Wang. Their teachings and passion for chemistry have been an inspiration. They have all been incredibly supportive, and I appreciate their time spent serving on my committee. I would additionally like to thank The University of Akron and the department of Chemistry for accepting me into the program and financially supporting me during my Ph.D. career. viii I would like to thank all group members in the lab (current and past). Thank you, Sanjay Gaire, and Huayi Wang for creating a supportive, and collaborative work environment. I would especially like to thank Laura Crandall for taking me under her wing. She is a great “Lab Mom” and friend to me. I am extremely grateful to Laura, Kullapa Chanawanno, Allen Osinski, and Dan Morris for accepting me right away into the group and showing me the ropes. They all took the time to help me with my research and have been great role models. I would also like to thank Dr. Boika’s group members for all their work and support involving the redox flow battery project. The electrochemical measurements and battery tests carried out by Zhiling Zhao, Baosen Zhang, and Arianna Frkonja-Kuczin have been most essential. I am especially grateful for Zhiling’s friendship and help over the years. I would also like to thank other graduate students, staff, and faculty who have provided help throughout these five years. Jason Bella has always been an incredible resource and great friend. Thank you, Mike Stromyer for all the help and training with the X-ray diffractometer. Thank you, Jason O’Neill, for always running my mass spec samples and working hard to evaluate everything with precision and care. I would also like to thank Bart, Simon, Venkat, Jessi, Nancy, and Jean- their help has been essential. Finally, I would like to thank my family. I could not have completed this journey without their love and care. They have been an incredible support system. ix TABLE OF CONTENTS LIST OF FIGURES ............................................................................................. xiii LIST OF TABLES ............................................................................................... xxi LIST OF SCHEMES .......................................................................................... xxii LIST OF ABBREVIATIONS .............................................................................. xxiii CHAPTER I. INTRODUCTION AND BACKGROUND ........................................................... 1 1.1 Redox Flow Batteries (Chapters II and III) ................................................ 1 RFB Design ...................................................................................................
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