UC Riverside UC Riverside Electronic Theses and Dissertations Title Carboranes: Building Blocks for Materials and Ligand Development Permalink https://escholarship.org/uc/item/2vp9m2z6 Author Estrada, Jess Steven Publication Date 2017 Peer reviewed|Thesis/dissertation eScholarship.org Powered by the California Digital Library University of California UNIVERSITY OF CALIFORNIA RIVERSIDE Carboranes: Building Blocks for Materials and Ligand Development A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemistry by Jess Steven Estrada September 2017 Dissertation Committee: Dr. Vincent Lavallo, Chairperson Dr. Richard Hooley Dr. Pingyun Feng Copyright by Jess Steven Estrada 2017 The Dissertation Jess Steven Estrada is approved: Committee Chairperson University of California, Riverside Acknowledgements I would like to thank Dr. Vincent Lavallo for giving me the opportunity to join his lab and for all of his help and support throughout graduate school. I owe a lot of my success to you. I would also like to thank the amazing faculty at UCR for all of their help and knowledge they have provided. I truly enjoyed every class I took here at UCR. In addition to the faculty, the staff in the chemistry department has been amazing over the last five years and played a huge role in my success as well so I would specifically like to thank Dr. Borchardt, the NMR genius, Dr. Fook for all of his help with my great looking X-ray structures, Christina Youhas for answering literally every question I ever had and being so kind about answering. My lab mates, who created the most unique group of people probably in the history of UCR and that I’ve ever had the pleasure of working with. You guys (and girl) are all awesome friends and co-workers and I wish you all nothing but the best in your future careers. I would like to thank my family and friends who have put up with me being MIA over the last five years and who have provided the encouragement and inspiration for me to be successful. Finally, saving the best and MOST important for last, I would like to thank my wife for putting up with all of the long hours (especially while finishing up those last few weeks) and god knows what else you put up with. I honestly could not have done this without you and I hope you know that. I dedicate this body of work to you and our beautiful son Miles. iv The text, figures, and schemes for the following chapters have been reproduced, in part or in their entirety, from the following published or submitted manuscripts. Chapter 2: “Resisting B-H Oxidative Addition: The Divergent Reactivity of the o- Carborane and Carba-closo-dodecaborate Ligand Substituents” J. Estrada, S.E. Lee, S. McArthur, A. El-Hellani, F.S. Tham, V. Lavallo, J. Organomet. Chem., 2015, 798, 214- 217 Chapter 3: “The Inductive Effects of 10 and 12-Vertex closo-Carborane Anion Ligand Substituents: Cluster Size and Charge Make a Difference” J. Estrada, C.A. Lugo, S.G. McArthur, V. Lavallo, Chem. Commun., 2016, 52, 1824-1826. Chapter 4: “Changing the Charge: Electrostatic Effects in Pd Catalyzed Cross Coupling” A.L. Chan, J. Estrada, C.E Kefalidis, V. Lavallo, Organometallics, 2016, 35, 3257–3260. Chapter 5: “Synthesis and Reactivity of a Zwitterionic Pd Allyl Complex Supported by a Perchlorinated Carboranyl Phosphine Ligand Substituents” J. Estrada, D.H. Woen, F.S. Tham, G.M. Miyake, V. Lavallo, Inorg. Chem., 2015, 54, 5142–5144. Chapter 6: “Fusing Dicarbollide Ions with N-Heterocyclic Carbenes” J. Estrada, V. Lavallo, to be submitted. Chapter 7: “Isolation of a Carborane-Fused Triazole Radical Anion” M. Asay, C. E. Kefalidis, J. Estrada, D. S. Weinberger, J. Wright, C. E. Moore, A. L. Rheingold, L. Maron, V. Lavallo, Angew. Chem. Int. Ed., 2013, 52, 11560-11563. v ABSTRACT OF THE DISSERTATION Carborane Anions: Building Blocks for Materials and Ligand Development by Jess Steven Estrada Doctor of Philosophy, Graduate Program in Chemistry University of California, Riverside, September 2017 Dr. Vincent Lavallo, Chairperson Carborane anions are prized molecules due to their unique structure and bonding, as well as their anomalous stability and resistance to thermal and chemical decomposition. Since their discovery over half a century ago, they have been exploited as weakly coordinating anions stabilizing the most reactive cationic species known, but applications in catalysis by appending carborane anions as ligand substituents had never been attempted. We report a number of carborane-supported zwitterionic and anionic late transition metal complexes to serve as proof of concept for the application of anionic carborane ligand substituents in transition metal catalysis. The results from our studies confirm the anionic carborane is indeed inherently more stable than its isoelectronic neutral cousin, making it a suitable candidate for applications in catalysis. The donor properties of the 12 and 10 vertex anionic carboranes were probed to allow for the possibility of logical tuning of a given transition metal catalyst. Applications in catalysis and studies on the effect of charge as well as the development of a novel N-dicarbollide N-heterocyclic carbene are also reported. The work herein, should mitigate the development of novel single component zwitterionic and vi anionic transition metal complexes for applications including, but not limited to hydrogenation, dehydrogenation, α-olefin polymerization, as well as various cross coupling reactions. In addition to the aforementioned, the isolation of the first triazole radical anion is disclosed as well as the methodology to develop a library of potential isolable triazole radical anions for applications in functional materials. vii Table of Contents Acknowledgements .................................................................................................................................................. iv List of Figures ............................................................................................................................................................ x List of Schemes ....................................................................................................................................................... xii Chapter 1: Introduction ...................................................................................................................................... 1 1.1 Background ................................................................................................................................................. 1 1.2 Synthesis and functionalization of H2C2B10H10 ............................................................................... 4 1.3 Synthesis of nido-carborane 7,8-C2B9H12 ......................................................................................... 6 - 1.4 Synthesis and functionalization of HCB11H11 ................................................................................. 9 - 1.5 Synthesis and functionalization of HCB9H9 .................................................................................. 11 1.6 References ................................................................................................................................................. 15 Chapter 2: Resisting B-H Oxidative Addition: The Divergent Reactivity of the o-Carborane - (C2B10H10) and Carba-closo-dodecaborate (CB11H11 ) Ligand Substituents ................................. 19 2.1 Abstract ...................................................................................................................................................... 19 2.2 Introduction .............................................................................................................................................. 19 2.3 Results and Discussion.......................................................................................................................... 21 2.4 Summary and Conclusion .................................................................................................................... 24 2.5 Experimental ............................................................................................................................................ 24 2.6 References ................................................................................................................................................. 25 Chapter 3: The Inductive Effects of 10 and 12-Vertex closo-Carborane Anion Ligand Substituents: Cluster Size and Charge Make a Difference ................................................................ 29 3.1 Abstract ...................................................................................................................................................... 29 3.2 Introduction .............................................................................................................................................. 29 3.3 Results and Discussion.......................................................................................................................... 31 3.4 Summary and Conclusion .................................................................................................................... 36 3.5 Experimental ............................................................................................................................................ 36 3.6 References ................................................................................................................................................