THE SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF MAIN GROUP AND TRANSITION METAL COMPLEXES SUPPORTED BY NITROGEN BASED LIGANDS by LESLIE ANNE LESIKAR Bachelor of Science, May 2005 Texas Christian University Fort Worth, Texas Submitted to the Graduate Faculty of the College of Science and Engineering Texas Christian University in partial fulfillment of the requirements for the degree of Doctorate of Philosophy December, 2008 Copyright By Leslie Anne Lesikar 2008 ACKNOWLEDGEMENTS To begin, I would like to thank my graduate research advisor Dr. Anne F. Richards for her extensive patience and encouragement. She has truly been an inspirational figure in my life offering a profound knowledge of chemistry that I admire. Her assistance helping me to achieve independent critical thinking involving my research has exceeded my expectations, and I know will guide me to success and help me to become the person I am destined for. I am extremely blessed to have been a part of this research group. I also want to express my appreciation to the Texas Christian University Chemistry faculty for their never ending support and help. Specifically, I would like to say thank you to Dr. Jean-Luc Montchamp for the advice he always generously offered on my research. Additionally, I would like to thank my fellow graduate students that I have been so fortunate to work with in the Richards group and the department, always available for insightful scientific discussions. Finally, I would like to thank my family for supporting me throughout my graduate studies. My dad and mom for encouraging me to never give up on my goals and dreams, which has molded me into who I am today and the success I have accomplished with my education. Finally, to my brother who has always been there for me and been a persistent friend outside of my chemistry world. I would also like to thank TCU–RCAF and the Robert A Welch Foundation for their financial support. ii TABLE OF CONTENTS Acknowledgments ............................................................................................................. ii List of Abbreviations ..................................................................................................... viii List of Equations ................................................................................................................x List of Figures ................................................................................................................... xi List of Schemes .............................................................................................................. xvii List of Tables ....................................................................................................................xx CHAPTER I. Literature Review ..............................................................................................................1 1.1 β-Diketiminato Ligands ..............................................................................................2 1.1.1 β-Diketimines, a Useful Bidentate Ligand ..........................................................2 1.1.2 Synthesis of β-Diketiminates ..............................................................................4 1.1.3 Formation of Lithium and Sodium Derivatives...................................................6 1.2 β-Enaminoketonato Ligands ......................................................................................7 1.2.1 β-Ketoiminato Ligands ........................................................................................7 1.2.2 Advantages and Applications .............................................................................8 1.2.3 Synthesis of β-Ketiminates .................................................................................9 1.3 Amidine Ligands ......................................................................................................13 1.3.1 Introduction .......................................................................................................13 1.3.2 Metal Amidinate Coordination Modes and Structural Forms ..........................14 iii 1.3.3 Synthesis of Amidines ......................................................................................16 1.4 Pyridineselenolate and Pyrazinamide Ligands .........................................................18 1.4.1 Pyridineselenolate ..............................................................................................18 1.4.1.1 Introduction ........................................................................................18 1.4.1.2 Synthesis of Pyridineselenolates .......................................................19 1.4.1.3 Metal Pyridineselenolate Binding Modes .........................................22 1.4.2 Pyrazinamide .....................................................................................................23 1.4.2.1 Introduction ........................................................................................23 1.4.2.2 Synthesis of Pyrazinecarboxamides ..................................................25 1.4.2.3 Metal Pyrazinecarboxamide Binding Modes ....................................25 CHAPTER II. Synthesis and Characterization of β-Diketiminato Complexes Containing Sb(III) and As(III) Halides ........................................................................................................27 2.1 Introduction ..............................................................................................................28 2.2 Results and Discussion .............................................................................................31 2.2.1 Discussion of [(DippnacnacH)SbBr]2(μ-Br)2, 1 ................................................31 + – 2.2.2 Discussion of [(DippnacnacHSbCl2)SbCl] [Cl] , 2 ..........................................33 2.2.3 Discussion of [(Mesnacnac)SbCl2], 3 ................................................................35 2.2.4 Discussion of Further Chemistry, Compounds 4–7 ..........................................37 + – 2.2.5 Discussion of [(Dippnacnac)AsCl] [As2Cl4(μ-O)][Cl] , 8 ................................39 2.2.6 Discussion of Further Chemistry, Compounds 9–11 ........................................41 2.3 Summary ..................................................................................................................45 2.4 Experimental ............................................................................................................46 2.4.1 General Procedures ...........................................................................................46 2.4.2 Spectroscopy Measurements ............................................................................46 2.4.3 X-Ray Crystallography ......................................................................................46 iv 2.4.4 Experimental Procedures and Spectroscopic Data ............................................47 CHAPTER III. The Reactions of P(III) and Bi(III) Halides with β-Diketiminato Ligands ................53 3.1 Introduction ..............................................................................................................54 3.2 Results and Discussion .............................................................................................59 3.2.1 Discussion of [(DippnacnacH)PBr]+[Br]–, 12 ...................................................59 3.2.2 Discussion of [(MeDippnacnacH)PBr]+[Br]–, 13 ..............................................61 3.2.3 Discussion of [(DippnacnacPBr)2PBr], 14 ........................................................63 + – – 3.2.4 Discussion of 2[(DippnacnacH)PCl] [As2Br6(μ-Br)] [Br] , 15 ........................65 + + 4– 3.2.5 Discussion of [DippnacnacH2] 3[DippNH3] [Bi2Cl9(μ-Cl)] , 16 ....................68 3.3 Summary ..................................................................................................................71 3.4 Experimental ............................................................................................................72 3.4.1 General Procedures ...........................................................................................72 3.4.2 Spectroscopy Measurements ............................................................................72 3.4.3 Experimental Procedures and Spectroscopic Data ...........................................72 CHAPTER IV. Synthesis, Characterization, and Steric Hindrance Comparisons of Selected Transition and Main Group Metal β-Ketiminato Complexes ....................................76 4.1 Introduction ..............................................................................................................77 4.2 Results and Discussion .............................................................................................84 4.2.1 Discussion of [DippN(H){C(Me)}2C(Me)O]SnCl2, 17 ....................................84 4.2.2 Discussion of [DippN(H){C(Me)}2C(Me)O]SbCl3, 18 ....................................85 4.2.3 Discussion of [Et2NC2H4NC(Me)CHC(Me)O]SbCl2, 19 ..................................86 4.2.4 Discussion of [DippN{C(Me)}2C(Me)O]2InCl, 20 ...........................................88 v 4.2.5 Discussion of [Et2NC2H4NC(Me)CHC(Me)O]InCl2, 21 ..................................91 4.2.6 Discussion of [Et2NC2H4NC(Me)CHC(Me)O]GaCl2, 22 .................................93 4.2.7 Discussion of [Et2NC2H4NC(Me)CHC(Me)O]ZnEt, 23 ...................................95 4.2.8 Discussion of [Et2NC2H4NC(Me)CHC(Me)O]MnCl–ClLi(thf)2, 24 ................98