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Cationic Cryptand Complexes of Germanium(Ii) and Tin(Ii): Synthesis and Reactivity

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Cationic Cryptand Complexes of Germanium(Ii) and Tin(Ii): Synthesis and Reactivity Western University Scholarship@Western Digitized Theses Digitized Special Collections 2011 CATIONIC CRYPTAND COMPLEXES OF GERMANIUM(II) AND TIN(II): SYNTHESIS AND REACTIVITY Jessica C. Avery Follow this and additional works at: https://ir.lib.uwo.ca/digitizedtheses Recommended Citation Avery, Jessica C., "CATIONIC CRYPTAND COMPLEXES OF GERMANIUM(II) AND TIN(II): SYNTHESIS AND REACTIVITY" (2011). Digitized Theses. 3279. https://ir.lib.uwo.ca/digitizedtheses/3279 This Thesis is brought to you for free and open access by the Digitized Special Collections at Scholarship@Western. It has been accepted for inclusion in Digitized Theses by an authorized administrator of Scholarship@Western. For more information, please contact [email protected]. CATIONIC CRYPT AND COMPLEXES OF GERMANIUM(II) AND TIN(II): SYNTHESIS AND REACTIVITY (Spine title: Cationic Cryptand Complexes of Germanium(II) and Tin(II)) (Thesis format: Integrated-Article) by Jessica C. Avery Graduate Program in Chemistry ! A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science The School of Graduate and Postdoctoral Studies The University of Western Ontario London, Ontario, Canada © Jessica C. Avery, 2011 THE UNIVERSITY OF WESTERN ONTARIO THE SCHOOL OF GRADUATE AND POSTDOCTORAL STUDIES CERTIFICATE OF EXAMINATION Supervisor Examiners Dr. K. M. Baines Dr. J. F. Corrigan Dr. B. L. Pagenkopf Dr. R. L. Linnen The thesis by Jessica C. Avery entitled: Cationic Cryptand Complexes of Germanium(II) and Tin(II): Synthesis and Reactivity is accepted in partial fulfilment of the requirements for the degree of Master of Science Date___________________________ ________________________________ Chair of the Thesis Examination Board li Abstract The synthesis, structural characterization and reactivity of cryptand complexed tin(II) cations (43-46), as well as the reactivity of a cryptand complexed germanium dication 36, are examined in this thesis. A series of tin(II) cations were synthesized by the addition of cryptand[2.2.2] to a solution of a tin(II) precursor (SnCU, S11I2 or Sn(OTf)2), resulting in the formation of 43, 45 and 46, respectively. An alternative synthetic route for 45 and 46, and the primary route for 44, involved the addition of the appropriate trimethylsilyl reagent to a solution of cryptand[2.2.2] and SnC^ to perform a halide/pseudohalide exchange. The reactivity of 36, 43 and 44 were examined as synthons for Ge(II) and Sn(II) compounds. Compound 36 was reacted with a variety of anionic and neutral reagents in the presence of known germylene trapping reagents: N-heterocyclic carbene, 2,3- dimethylbutadiene (DMB) and 3,5-di-tert-butyl ori/jo-quinone (3,5-D'BoQ). The addition of acetylacetone (acac), dibenzoylmethane and their conjugate bases to the cations 36, 43 or 46 was also studied in the absence of a trapping reagent. Anionic or neutral reagents with a low pKa (~9) are required to add to the germanium or tin. The NHC appeared to trap the germylene in good yield, whereas DMB did not give the predicted adduct. Attempts to abstract the halide from 43, 44 and 45 as well as competition reactions between [(15-crown-5)2Sn][OTf]2 and 46 are also examined. m Keywords: cation, cryptand, coordination complex, tin(II), germanium(II), germylene, stannylene . * IV Co-Authorship Chapter 2 involves some collaborative work. All experimental work was performed by Jessica C. Avery, with the exception of the [NBatJfSnXa] compounds which were synthesized by Margaret A. Hanson. Rolfe H. Herber at Racah Institute of Physics, The Hebrew University of Jerusalem was responsible for the collection of Mossbauer spectroscopic data for compounds 43-46. Margaret A. Hanson and Yining Huang at The University of Western Ontario collected and analyzed solid state NMR spectroscopic data and performed calculations for compounds 43-46. X-ray diffraction data for compounds 43, 44 and 46 were collected and analyzed by Paul A. Rupar at The University of Western Ontario. — For Chapters 2 and 3, acquisition of mass spectra was performed by Doug Hairsine at The University of Western Ontario. v Acknowledgements First of all, I would like to thank my supervisor, Kim Baines, for allowing me to join her research group. I greatly appreciate the guidance, support and encouragement she continuously provided throughout my time in her group. I am also very thankful for the opportunities to attend several conferences, including two international conferences, giving me the opportunity to travel to Austria. These conferences were amazing and an excellent learning experience that I will forever value. Thank you very much Kim. I would also like to thank the members of the Baines’ lab, past and present, for all the fun times and chemistry discussions. A special thanks goes out to Margaret Hanson who was extremely helpful with solid state NMR and computational analysis, as well as constantly lending an ear when it was just the two of us in the group. I am thankful to Dr. Paul Rupar for his guidance beginning my project and for acquiring X- ray data and solving their structures, as well as helpful discussions even after he graduated via email. I must also thank the faculty and staff at Western, especially Doug Hairsine for acquiring mass spectra, including some last minute data collections, Dr. Nick Payne for his help with X-ray data and SHELX, and Mat Willans for his help with NMR spectroscopy. Finally, I must thank my family, Mom, Dad and Alex, and my friends, especially Mike, for their constant love, support and encouragement to always follow my dreams and succeed in my endeavours. I am most grateful for their patience, as I can be indecisive. You are all amazing! vi Table of Contents Page Certificate of Examination.....................................................................................................ii Abstract...................................................................................................................................iii Keywords................................................................................................................................iv Co-Authorship.........................................................................................................................v Acknowledgements............................................................................................................... vi Table of Contents................................................................................................................. vii List of Tables..........................................................................................................................xi List of Figures........................................................................................................................xii List of Abbreviations............................................................................... xiii Cast of Characters.................................................................................................................xvi Chapter 1 An Introduction to Cationic Complexes of Group 14 1.1 General Introduction....................................................................................................1 1.2 Tricoordinate Group 14 Cations.................................................................................2 1.2.1 Free Tricoordinate Cations of Group 14..........................................................3 1.2.2 Hypercoordinated E(IV) Cations...................................................................... 7 1.3 Low Valent Cations of Group 14 ..............................................................................8 1.3.1 E(II) Cations Stabilized by Carbon Donors......................................................9 1.3.2 E(II) Cations Stabilized by Nitrogen Donors.................................................12 1.3.3 E(II) Cations Stabilized by Oxygen Donors in Macrocycles........................16 1.4 Project Overview.......................................................................................................22 vii 1.5 References...................................................................................................................22 Chapter 2 Synthesis and Characterization of Tin(II) Cryptand Complexes 2.1 Introduction.............................................................................................................. 28 2.2 Results and Discussion.............................................................................................32 2.2.1 Synthesis and Characterization of Monocationic Cryptand Complexes ofTin(II)................................................................................... 32 2.2.2 Synthesis and Characterization of a Dicationic Cryptand Complex of Tin(II).......................................................................................48 2.3 Conclusions...............................................................................................................56 2.4 Experimental..............................................................................................................57 2.4.1 Synthesis of 43 and Direct Synthesis of 45 and 4 6 .................................... 57 2.4.2 Typical Syntheses of 44, 45a and 46...........................................................59 2.4.3 119Sn Môssbauer Spectroscopy.................................................................... 59 2.4.4 119Sn SSNMR Spectroscopy........................................................................ 60 2.4.5 SSNMR
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