The University of Southern Mississippi The Aquila Digital Community Dissertations Spring 5-2008 The Design, Synthesis, and Controlled Polymerization of Cationic and Zwitterionic Norbornene Derivatives David Allen Rankin University of Southern Mississippi Follow this and additional works at: https://aquila.usm.edu/dissertations Part of the Polymer Chemistry Commons Recommended Citation Rankin, David Allen, "The Design, Synthesis, and Controlled Polymerization of Cationic and Zwitterionic Norbornene Derivatives" (2008). Dissertations. 1190. https://aquila.usm.edu/dissertations/1190 This Dissertation is brought to you for free and open access by The Aquila Digital Community. It has been accepted for inclusion in Dissertations by an authorized administrator of The Aquila Digital Community. For more information, please contact [email protected]. The University of Southern Mississippi THE DESIGN, SYNTHESIS, AND CONTROLLED POLYMERIZATION OF CATIONIC AND ZWITTERIONIC NORBORNENE DERIVATIVES by David Allen Rankin A Dissertation Submitted to the Graduate Studies Office of The University of Southern Mississippi in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Approved: COPYRIGHT BY DAVID ALLEN RANKIN 2008 The University of Southern Mississippi THE DESIGN, SYNTHESIS, AND CONTROLLED POLYMERIZATION OF CATIONIC AND ZWITTERIONIC NORBORNENE DERIVATIVES by David Allen Rankin Abstract of a Dissertation Submitted to the Graduate Studies Office of The University of Southern Mississippi in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy May 2008 ABSTRACT THE DESIGN, SYNTHESIS, AND CONTROLLED POLYMERIZATION OF CATIONIC AND ZWITTERIONIC NORBORNENE DERIVATIVES by David Allen Rankin May 2008 Ring opening metathesis polymerization (ROMP) has been exploited for the controlled polymerization of cationic and zwitterionic norbornene-based monomers and employed in the preparation of homo- and block-copolymer systems in homogeneous organic media without the use of post polymerization modification or protecting group chemistries. Relying on previous knowledge of certain halogenated alcoholic organic solvents capable of solubilizing hydrophilic monomers, the first study, describes the synthesis and controlled polymerization of a series of new permanently cationic ammonium exo-7- oxanorbornene derivatives M31 via ROMP, with the first generation Grubbs catalyst 17, in a novel solvent mixture comprised of 1:1 vol/vol 2,2,2-trifluoroethanol (TFE)/methylene chloride (CH2CI2). This cosolvent mixture was demonstrated to be a convenient reaction medium facilitating the polymerization of hydrophilic substrates by hydrophobic initiators under homogeneous conditions. Homo- and copolymerizations proceed rapidly yielding materials with controlled molecular masses, and narrow molecular mass distributions. It was demonstrated that this protocol is not limited to the use of TFE as a cosolvent and that additional halogenated alcohols, such as 2,2,2- trichloroethanol (TCE) and 1,1,1,3,3,3-hexafluoroisopropanol (HFIP), are also effective ii cosolvents for the controlled polymerization of such substrates. Finally, we demonstrate that the TFE/CH2CI2 mixture has no apparent detrimental effect on 17. The second study describes results relating to the effect of halide counterion on the ROMP of a permanently cationic exo-7-oxanorbornene derivative whose synthesis we described recently in the presence of the 17. Statistical copolymerizations of exo-benzyl- [2-(3,5-dioxo-10-oxa-4-aza-tricyclo[5.2.1.0 ' ]dec-8-en-4-yl)-ethyl]dimethyl ammonium bromide/chloride were conducted at molar ratios of 25:75, 50:50, and 75:25, and the polymerizations evaluated with respect to their kinetic features as well as their molecular mass profiles as a function of conversion and the ability to produce materials with narrow molecular mass distributions. Direct comparison of the statistical copolymerizations with the corresponding bromide/chloride homopolymerizations indicates that their polymerization characteristics are intermediate of that observed for the homopolymerizations. In all instances the copolymerizations appear controlled. The clearest effect is on the measured polydispersity index which in all instances coincides with that of the bromide homopolymerization and indicates a positive, beneficial effect even with only 25 mol% bromide comonomer. The polymerization characteristics are rationalized in terms of the in situ formation of the mixed Grubbs' derivative RuClBr(PCy3)2CHPh and/or the dibromo analog RuBr2(PCy3)2CHPh formed by halide exchange with the bromide counterions in exo-benzyl-[2-(3,5-dioxo-10-oxa-4-aza- tricyclo[5.2.1.02,6]dec-8-en-4-yl)-ethyl]dimethyl ammonium bromide MON-Bn-Cl. The third study describes the synthesis and controlled ROMP of highly functional zwitterionic sulfopropylbetaine- M32 and carboxyethylbetaine-ejco-7-oxanorbornene derivatives M33 with the first generation Grubbs' initiator 17 in a TFE/CH2CI2 solvent iii mixture. These are the first examples of such norbornene-based betaine substrates. Both species can be polymerized directly in a controlled manner in organic media as judged from the kinetic profiles and aqueous size exclusion chromatographic analysis. This represents the first time betaine monomers have been polymerized directly in a controlled fashion by a technique other than a controlled free radical polymerization process, and the first time it has have been achieved in organic, as opposed to aqueous, media. Finally, preliminary results demonstrate that water-soluble, salt-responsive AB diblock copolymers can be prepared and that such materials are able to undergo supramolecular self-assembly in aqueous media to yield nano-sized aggregates simply by controlling the aqueous electrolyte concentration. iv In loving memory of Beatrice and Jordan Ellis, and Clearease Cook. ACKNOWLEDGEMENTS First, I would like to thank Dr. Gloria Anderson and Dr. Tawfeq Kamari, my undergraduate mentors at Morris Brown College, for encouraging me to pursue a PhD. in chemistry. Dr. Tracy Hamilton of the University of Alabama at Birmingham is also acknowledged for his words of encouragement. I would like to express my sincere gratitude to my graduate research advisor, Dr. Andrew B. Lowe, for granting me the opportunity to work in an environment that fosters learning and scientific discovery. Many thanks to my Ph.D. advisory committee, Dr. Hans-Jorg Schanz, Dr. Douglas Masterson, Dr. John Pojman, Dr. Stephen Boyes and past committee member Dr. David Creed for their time, guidance, and constructive criticism. Dr. Alvin Holder is also acknowledged for being a friend and mentor. Special thanks to Rosie Stuart, Sharon King, and Dr. Robert Bateman for all their assistance over the years. Also, I would like to acknowledge Dr. Gordon Cannon for inviting me to pursue graduate studies in the Department of Chemistry and Biochemistry. I am grateful to my fellow graduate colleagues and the members of the Lowe Research Group, both past and present, for their friendship and support. Past and present members of AGEM are acknowledged for their camaraderie and support as well. Special thanks to Andre Heath, Dr. Joe Whitehead, and Dr. Rex Gandy for all their support over the years. Past and present financial support throughout my graduate career, which includes AGEM of the National Science Foundation, MRSEC program of the National Science vi Foundation (DMR-0213883) and the Department of Education-funded GAAN program (P200A060323), is gratefully acknowledged. Finally, I would like to express sincere gratitude to my wife, children, family and friends for unwavering love, words of encouragement, and support throughout my graduate career. Thanks for keeping me grounded. I wouldn't have made it without you. I love you all. vii TABLE OF CONTENTS ABSTRACT ii DEDICATION v ACKNOWLEDGMENTS vi LIST OF FIGURES x LIST OF SCHEMES xiv LIST OF TABLES xvi CHAPTER I. INTRODUCTION 1 Water-soluble Polymers 1 General Considerations for Water-soluble Polymers 2 Ion-containing (co)polymers 5 Polyelectrolytes 5 Polyzwitterions 10 Controlled/'Living' Polymerization 19 Ring-Opening Metathesis Polymerization (ROMP) 22 Accepted Mechanism and Other Aspects of ROMP 23 Living Ring-Opening Metathesis Polymerization (LROMP) 32 Ill-defined ROMP Initiators 34 Well-defined ROMP Initiators 34 Synthesis of Ion-containing (co)polymers via Classical ROMP, LROMP, and Homogeneous Aqueous LROMP 51 II. OBJECTIVES OF RESEARCH 63 III. THE CONTROLLED HOMOGENEOUS ORGANIC SOLUTION POLYMERIZATION OF NEW HYDROPHILIC CATIONIC exo-1- OXANORBORNENE WITH RUCl2(Cy3)2CHPh IN A NOVEL 2,2,2 TRIFLUOROETHANOL/METHYLENE CHLORIDE SOLVENT MIXTURE 68 Introduction 68 viii Experimental 68 Results and Discussion 77 Summary/Conclusions 102 IV. OBSERVATION ON THE EFFECT OF HALIDE COUNTERION IN THE ROMP OF THE exo-7-OXANORBORNENE DERIVATIVES exo-BENZYL-[2-(3,5-DIOXO-10-OXA-4-AZA- TRICYCLO[5.2.1.02,6]DEC-8-EN-4-YL)-ETHYL]DIMETHYL AMMONIUM BROMIDE/CHLORIDE IN 2,2,2- TRIFLUOROETHANOL/METHYLENE CHLORIDE 104 Introduction 105 Experimental 105 Results and Discussion 106 Summary/Conclusions 117 V. NEW WELL-DEFINED POLYMERIC BETAINES: FIRST REPORT DETAILING THE SYNTHESIS AND ROMP OF SALT-RESPONSIVE SULFOPROPYLBETAINE- AND CARBOXYETHYLBETAINE-exo-7-OXANORBORNENE MONOMER 119 Introduction 119 Experimental 120 Results and Discussion 126 Summary/Conclusions 146 VI. CONCLUSIONS AND FUTURE DIRECTIONS 148 REFERENCES 151 ix LIST OF FIGURES Figure 1-1. Functional groups that impart water solubility 2 1-2. Structural