ABSTRACT PÉREZ, DAMARIS ESTHER. Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiometric and Insertion Reactions. (Under the direction of Elon A. Ison). This document focuses on the synthesis and characterization of new rhenium(III) complexes bearing tridentate pincer ligands. These organometallic complexes were subject to comprehensive studies of their reactivity towards catalytic, stoichiometric and insertion reactions. Mechanistic studies of these transformations will lead to the development of more efficient catalytic systems. In Chapter 2, cationic bisacetonitrile diamidoamine (DAAm) rhenium(III) and cationic diamineamido (DAmA) rhenium(III) complexes were synthetized, and characterized. Their reactivity towards the hydrosilylation reaction of aldehydes was studied. It was proposed through experimental and kinetic data that the most likely pathway for this transformation follows a non- hydride ionic hydrosilylation mechanism. Various aliphatic and aromatic aldehydes were tested. Excellent yields were achieved at ambient temperature in neat conditions using dimethylphenylsilane. The reaction affords TONs of up to 9,200 and a TOF of up to 126 h-1. In Chapter 3, a computational mechanistic study of the hydrosilylation reaction of aldehydes by novel cationic rhenium(III) bisacetronitrile complex is presented. DFT analysis supports a non-hydride ionic hydrosilylation mechanism which was previously proposed based on experimental and kinetic data. In Chapter 4, the reactivity of novel DAAm-C6F5 rhenium(III) acetate complex towards Lewis acidic boron reagents was investigated. The role of water as an oxygen source was studied. Novel rhenium(III) and rhenium(V) complexes bearing a C6F5 ligand were synthesized, characterized, and proposed as intermediates. Mechanistic transformations were proposed base on experimental data and previous reports in the literature. In Chapter 5, new diamidoamine (DAAm) rhenium(III) aryl complexes were synthetized and characterized. Kinetic studies suggest a pseudo-first order overall reaction. The mechanism for the CO insertion with rhenium(III) complexes was proposed. Comparison of rhenium(III) versus rhenium(V) for CO activation was established. © Copyright 2018 Damaris Esther Pérez All Rights Reserved Synthesis, Characterization and Reactivity of Rhenium(III) Complexes for Catalytic, Stoichiometric and Insertion Reactions by Damaris Esther Pérez A dissertation submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Chemistry Raleigh, North Carolina 2018 APPROVED BY: ______________________________ _____________________________ Dr. Elon A. Ison Dr. Reza Ghiladi Committee Chair ______________________________ _____________________________ Dr. Elena Jakubikova Dr. Joshua Pierce DEDICATION To my husband, Hernán To my baby girl, Sofía Esther To my parents, Zory and Fidel To my sisters, Sandra and Vivian To my grandparents, Mama Candy (1928 - 2012) and Papa Tato For your support and unconditional love. ii BIOGRAPHY Damaris Esther Pérez (formerly Rivera-Santos) was born on September 13th, 1986 in Aibonito, Puerto Rico. She and her sisters, Sandra and Vivian were raised by their parents, Fidel and Zoraida. From an early age, she had a passion for math and science. Damaris graduated from Bonifacio Sánchez Jiménez high school in May 2004 and moved to San Juan, Puerto Rico to complete her undergraduate degree at University of Puerto Rico at Río Piedras (UPR-RP). She graduated with a Bachelor of Science degree in Chemistry in May 2009. Upon graduation, she stayed at UPR-RP took graduate courses and worked as a teaching assistant. Then, in August 2010, she moved to Oswego, New York to pursue a Master’s Degree in Chemistry at the State University of New York (SUNY) at Oswego. She conducted graduated research under the supervision of Dr. Fehmi Damkaci in organic chemistry and worked as a teaching assistant. She graduated with a M.S. in chemistry in May 2012 and then moved to Lincoln, Nebraska. In August 2012, she started graduated research under the supervision of Dr. James Takacs in organic chemistry and worked as a teaching assistant at University of Nebraska Lincoln (UNL). In May 2013, she moved to Raleigh, North Carolina to pursue her Ph.D. in Chemistry at North Carolina State University. Since arriving to NC State University, she has been conducting her doctoral research in organometallic chemistry under the direction of Dr. Elon A. Ison. Upon graduation in 2018, Damaris plans to pursue a professional career in chemical industry. iii TABLE OF CONTENTS LIST OF TABLES ......................................................................................................................... vi LIST OF FIGURES ...................................................................................................................... vii LIST OF SCHEMES ...................................................................................................................... ix Chapter 1: General Introduction ................................................................................................ 1 1.1 Organometallic Chemistry .................................................................................................... 2 1.2 Scope of this dissertation ...................................................................................................... 3 1.3 References ............................................................................................................................. 5 Chapter 2: Cationic Rhenium(III) Complexes: Synthesis, Characterization, and Reactivity for Catalytic Hydrosilylation Reaction of Aldehydes ...................................... 7 2.1 Abstract ................................................................................................................................. 8 2.2 Introduction ........................................................................................................................... 8 2.3 Results and Discussion ....................................................................................................... 10 2.4 Conclusions ......................................................................................................................... 34 2.5 Experimental Section .......................................................................................................... 35 2.6 References ........................................................................................................................... 42 Chapter 3: Mechanistic Investigation of the Hydrosilylation Reaction of Aldehydes by a Bisacetonitrile Cationic Rhenium(III) Complex: A Computational Study .................................................................................................................. 44 3.1 Abstract ............................................................................................................................... 45 3.2 Introduction ......................................................................................................................... 45 3.3 Results and Discussion ....................................................................................................... 49 3.4 Conclusions ......................................................................................................................... 59 3.5 Experimental Section .......................................................................................................... 60 3.6 References ........................................................................................................................... 61 Chapter 4: Reactivity of Novel DAAm Rhenium(III) Acetate Complex Towards Lewis Acidic Boron Reagents .................................................................................... 64 4.1 Abstract ............................................................................................................................... 65 4.2 Introduction ......................................................................................................................... 65 4.4 Conclusions ......................................................................................................................... 83 4.5 Experimental Section .......................................................................................................... 84 4.6 References ........................................................................................................................... 91 Chapter 5: Synthesis and Characterization of (DAAm)ReIII(CO)(R) Complexes, and Study of CO Insertion into Rhenium(III)-Carbon Bond ............................ 93 iv 5.1 Abstract ............................................................................................................................... 94 5.2 Introduction ......................................................................................................................... 94 5.3 Results and Discussion ....................................................................................................... 97 5.5 Conclusions ....................................................................................................................... 115 5.6 Experimental Section ........................................................................................................ 116 5.7 References ........................................................................................................................