UNLV Theses, Dissertations, Professional Papers, and Capstones 8-1-2015 Hydrothermal Routes to Technetium Cluster Compounds William M. Kerlin University of Nevada, Las Vegas Follow this and additional works at: https://digitalscholarship.unlv.edu/thesesdissertations Part of the Chemistry Commons Repository Citation Kerlin, William M., "Hydrothermal Routes to Technetium Cluster Compounds" (2015). UNLV Theses, Dissertations, Professional Papers, and Capstones. 2485. http://dx.doi.org/10.34917/7777313 This Dissertation is protected by copyright and/or related rights. It has been brought to you by Digital Scholarship@UNLV with permission from the rights-holder(s). You are free to use this Dissertation in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s) directly, unless additional rights are indicated by a Creative Commons license in the record and/or on the work itself. This Dissertation has been accepted for inclusion in UNLV Theses, Dissertations, Professional Papers, and Capstones by an authorized administrator of Digital Scholarship@UNLV. For more information, please contact [email protected]. HYDROTHERMAL ROUTES TO TECHNETIUM CLUSTER COMPOUNDS By William Michael Kerlin Bachelor of Science in Chemistry California State University of Sacramento 2004 A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy - Radiochemistry Department of Chemistry College of Sciences The Graduate College University of Nevada, Las Vegas August 2015 Copyright by William M. Kerlin, 2015 All Rights Reserved Dissertation Approval The Graduate College The University of Nevada, Las Vegas July 2, 2015 This dissertation prepared by William M. Kerlin entitled Hydrothermal Routes to Technetium Cluster Compounds is approved in partial fulfillment of the requirements for the degree of Doctor of Philosophy – Radiochemistry Department of Chemistry and Biochemistry Kenneth R. Czerwinski, Ph.D. Kathryn Hausbeck Korgan, Ph.D. Examination Committee Co-Chair Graduate College Interim Dean Paul M. Forster, Ph.D. Examination Committee Member Frederic Poineau, Ph.D. Examination Committee Member Alfred P. Sattelberger, Ph.D. Examination Committee Member Ralf Sudowe, Ph.D. Graduate College Faculty Representative ii ABSTRACT Hydrothermal Routes to Technetium Cluster Compounds By William M. Kerlin Dr. Kenneth Czerwinski, Advisory Committee Chair Professor of Chemistry University of Nevada, Las Vegas Transition metals of groups six through nine exhibit unique direct multiple metal- metal bonding cores. Technetium is a group seven transition metal and is the lightest radioelement in the periodic table. Technetium exhibits nine oxidation states (from -I to VII) and an extensive set of mixed oxidation states due to bi- or poly- nuclear complex formation. Technetium has no stable isotopes and thirty four technetium isotopes have been discovered. Two main isotopes are of great importance 99Tc and its metastable 99m 99m nuclear isomer Tc. The isotope Tc (T1/2 = 6.01 hours, γ = 140.5 keV) is used in 99 5 diagnostic nuclear medicine while Tc (T1/2 = 2.13x10 years, β = 294 keV) is a prominent fission product and is mainly used in fundamental technetium chemistry research due to its long half-life. The isotope 99Tc is a concern in nuclear waste management due to its high production rate, mobility in the environment, long half-life and radiotoxicity. The rapid use of technetium in various diagnostic procedures extended its coordination chemistry but the fundamental chemistry of low valent iii technetium is not as well explored compared to the surrounding elements Mo, Re, and +n Ru. Currently over 200 compounds containing the Re2 (n = 4, 5, 6) cores are known, +n whereas less than 30 compounds with Tc2 (n = 4, 5, 6) cores exist. One example of a +6 Tc2 core is Tc2(O2CCH3)4Cl2 which has been shown to be a useful starting compound for the synthesis of technetium binary halides. Hydro/solvo-thermal synthesis methods are used to reduce pertechnetate species, Tc(VII), to low-valent stable Tc-Tc dimers by changing the temperature and pressure of the system under constant volume and with different salts and acids. Results of these hydro/solvo-thermal reactions have yielded various new ditechnetium compounds that show interesting structures and properties. This study will focus on the synthesis of molecular metal-metal bonded technetium compounds like Tc2(μ-O2CCH3)4X2, (X = Cl, Br), polymeric metal-metal bonded technetium compounds or chains as [Tc2(μ-X)4(η-Y)]n, (X = carboxylate; Y = carboxylate, I) and technetium cluster chemistry involving iodide as polynuclear species for K[Tc8(μ- I)8I4]I, and Tc5I5(μ-I)4(μ3-I)4. As a result, these studies related to the synthesis of technetium dimers/clusters will permit acquisition of new information on technetium metal-metal bond chemistry and thus extend the fundamental knowledge of this element as well as its potential applications in the nuclear fuel cycle or nuclear medicine. iv ACKNOWLEDGMENTS I would like to thank first my advisor, Pr. Kenneth Ronald Czerwinski, for selecting me to be part of his research program and to allow me to express myself in the laboratory by doing synthesis with transition metals (technetium-99) as well transuranic compounds. The work presented in this thesis would not have been possible either without the presence, help and advice given by my committee. Their inputs and suggestions made me grown in technetium chemistry as well as in characterization techniques. Pr. Paul Foster was a significant help during my research method development and crystallographic studies. Dr. Frederic Poineau and Dr. Alfred Sattelberger were key contributors and source of information about technetium chemistry during this study. Dr. Sattelberger has an infectious desire to do synthesis and research daily; without his enthusiasm much of this work described below may have gone without notice to the scientific community. I shall always include him in my future endeavors of science. I appreciated being part of the radiochemistry group at UNLV and participating to various projects. I would like to thank Tom O’Dou, Julie Bertoia and Trevor Low for making the laboratory work efficiently. And thank you to my labmates for their advice and help. The support of my friends and family throughout the last five years was what pushed me through to the end. My parents, Mary P. Kerlin and Brent W. Kerlin have v always supported me in my adventures which helped tremendously. I would like to especially thank Maryline Ferrier for her extensive support and being around when I needed to vent. Without you, I would have never imagined completing this work, I would have stayed in the laboratory working on various new syntheses. Many thanks to a great professor of Physical Chemistry, as well as my mentor, supporter and friend Dr. Jeffery Mack of California State University of Sacramento with whom I have shared many great times. vi TABLE OF CONTENTS ABSTRACT ...................................................................................................................... iii ACKNOWLEDGMENTS .................................................................................................... v TABLE OF CONTENTS.................................................................................................... vii LIST OF TABLES ............................................................................................................. xii LIST OF FIGURES ........................................................................................................... xx CHAPTER 1: INTRODUCTION ......................................................................................... 1 1.1 Background....................................................................................................... 1 1.2 Metal-metal bonded compounds .................................................................... 5 1.2.1 Transition metals ....................................................................................... 5 1.2.2 Technetium ............................................................................................... 8 1.2.3 Comparison of technetium and surrounding elements .......................... 14 1.2.3.1 Classic starting materials .................................................................. 14 1.2.3.2 Molecular carboxylate structures, M2(O2CR)nXz .............................. 18 1.2.3.3 Polymeric carboxylate chain structures, M2(O2CR)nX ...................... 19 1.2.3.4 Known polynuclear cluster compounds ........................................... 20 CHAPTER 2: Materials and Methods ........................................................................... 21 2.1 Materials and methods used ......................................................................... 21 vii 2.1.1 Synthesis and characterization of KTcO4 ................................................ 21 2.1.2 Hydro/Solvo-thermal reaction techniques ............................................. 23 2.2 Characterization techniques .......................................................................... 29 2.2.1 Single crystal X-ray Diffraction (SC-XRD) ................................................. 29 2.2.1.1 Principle ............................................................................................ 29 2.2.1.2 Procedure ........................................................................................