Isolation of Lead-Amino Acid and Mercury-Amino Acid Complexes

175 Pages·2009·4.38 MB·English

Isolation of Lead-Amino Acid and Mercury-Amino Acid Complexes with
Characterization in the Solid State, the Solution State, and the Gas Phase

by

Cheryl D.L. Saunders

Submitted in partial fulfillment of the requirements
for the degree of Doctor of Philosophy

at

Dalhousie University
Halifax, Nova Scotia
August 2009

© Copyright by Cheryl D.L. Saunders, 2009
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DALHOUSIE UNIVERSITY

DATE: August 11, 2009
AUTHOR: Cheryl D.L. Saunders
TITLE: Isolation of Lead-Amino Acid and Mercury-Amino Acid Complexes with
Characterization in the Solid State, the Solution State, and the Gas Phase
DEPARTMENT OR SCHOOL: Department of Chemistry
DEGREE: PhD CONVOCATION: October YEAR: 2009
Permission is herewith granted to Dalhousie University to circulate and to have
copied for non-commercial purposes, at its discretion, the above title upon the request of
individuals or institutions.
_______________________________
Signature of Author

The author reserves other publication rights, and neither the thesis nor extensive
extracts from it may be printed or otherwise reproduced without the author’s written
permission.

The author attests that permission has been obtained for the use of any
copyrighted material appearing in the thesis (other than the brief excerpts requiring only
proper acknowledgement in scholarly writing), and that all such use is clearly
acknowledged.

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For my family and friends

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TABLE OF CONTENTS

LIST OF TABLES ............................................................................................................ xii
LIST OF FIGURES .......................................................................................................... xii
ABSTRACT ..................................................................................................................... xvi
LIST OF ABBREVIATIONS USED ............................................................................. xvii
ACKNOWLEDGEMENTS .............................................................................................. xx
CHAPTER 1 INTRODUCTION ........................................................................................ 1
1.1 METALS IN THE ENVIRONMENT .................................................................................. 1
1.2 METALS IN BIOLOGICAL SYSTEMS ............................................................................. 3
1.3 BIOLOGICAL MOLECULES .......................................................................................... 6
1.4 CHEMISTRY OF MERCURY AND LEAD ...................................................................... 10
1.4.1 Relativistic Effects ........................................................................................... 10
1.4.2 Hard-Soft Acid-Base Theory and Donor-Acceptor Strength .......................... 13
1.4.3 Donor-Acceptor Complexes ............................................................................ 15
1.4.4 Solid State Coordination Geometries of Lead(II) ............................................ 16
1.4.5 Solid State Coordination Geometries of Mercury ........................................... 21
1.4.6 Solution Chemistry of Metal Ions .................................................................... 25
1.4.7 Gas Phase Metal-Ligand Complexes ............................................................... 29
1.5 CHARACTERIZATION TECHNIQUES ........................................................................... 31
1.5.1 X-Ray Crystallography .................................................................................... 32
1.5.2 Nuclear Magnetic Resonance Spectroscopy .................................................... 34
1.5.3 Electrospray Ionization Mass Spectrometry .................................................... 40
1.5.4 Other Characterization Techniques ................................................................. 44

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1.6 SUMMARY ................................................................................................................ 45
CHAPTER 2 LEAD-AMINO ACID COMPLEXES ....................................................... 47
2.1 INTRODUCTION ......................................................................................................... 47
2.2 RESULTS AND DISCUSSION: SOLID STATE CHARACTERIZATION ............................... 48
2.2.1 Single Crystal X-Ray Diffraction: Lead-L-Valine .......................................... 48
2.2.2 Single Crystal X-Ray Diffraction: Lead-L-Isoleucine ..................................... 51
2.2.3 Single Crystal X-Ray Diffraction: Lead-L-Valine-L-Isoleucine ..................... 54
2.2.4 Single Crystal X-Ray Diffraction: Lead-L-Phenylalanine Complexes ........... 57
2.2.5 Single Crystal X-Ray Diffraction: Lead-L-Arginine ....................................... 61
2.2.6 Lead Coordination Environment: Hemidirected versus Holodirected
Geometries ................................................................................................................ 65
2.2.7 Lead-207 Solid State NMR Spectroscopy ....................................................... 67
2.2.8 Carbon-13 Solid State NMR Spectroscopy ..................................................... 69
2.3 RESULTS AND DISCUSSION: SOLUTION STATE CHARACTERIZATION ........................ 75
2.3.1 Solution Characterization and Determination of Solution pD ......................... 76
2.3.2 Lead-207 Solution NMR Spectroscopy ........................................................... 76
2.3.3 Carbon-13 Solution NMR Spectroscopy ......................................................... 80
2.3.4 Hydrogen-1 Solution NMR Spectroscopy ....................................................... 83
2.3.5 Solution Characterization Ionic Strength Effect .............................................. 84
2.4 RESULTS AND DISCUSSION: GAS PHASE CHARACTERIZATION ................................. 85
2.4.1 ESI-MS ............................................................................................................ 85
2.6 CONCLUSIONS .......................................................................................................... 88
CHAPTER 3 MERCURY-ALANINE COMPLEXES..................................................... 89
3.1 INTRODUCTION ......................................................................................................... 89

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3.2 RESULTS AND DISCUSSION: SOLID STATE CHARACTERIZATION ............................... 90
3.2.1 Single Crystal X-Ray Diffraction .................................................................... 90
3.2.2 Solid State NMR Spectroscopy ....................................................................... 96
3.2.3 IR Spectroscopy and Raman Spectroscopy ..................................................... 97
3.3 RESULTS AND DISCUSSION: SOLUTION STATE CHARACTERIZATION ........................ 98
3.3.1 Solution Characterization................................................................................. 98
3.3.2 Hydrogen-1 Solution NMR Spectroscopy ....................................................... 99
3.3.3 Carbon-13 Solution NMR Spectroscopy ....................................................... 104
3.4 RESULTS AND DISCUSSION: GAS PHASE CHARACTERIZATION ............................... 105
3.4.1 ESI-MS .......................................................................................................... 105
3.5 CONCLUSION .......................................................................................................... 108
CHAPTER 4 MERCURY-SECONDARY AMINO ACID COMPLEXES ................... 109
4.1 INTRODUCTION ....................................................................................................... 109
4.2 RESULTS AND DISCUSSION: SOLID STATE CHARACTERIZATION ............................. 110
4.2.1 Single Crystal X-Ray Diffraction: Mercury-L-Proline .................................. 110
4.2.2 Single Crystal X-Ray Diffraction: Mercury-N-Methyl-L-Alanine ................ 112
4.2.3 Vibrational Spectroscopy ............................................................................... 114
4.3 RESULTS AND DISCUSSION: SOLUTION STATE CHARACTERIZATION ...................... 115
4.3.1 Solution NMR Characterization .................................................................... 115
4.3.2 Hydrogen-1 NMR Spectroscopy ................................................................... 115
4.3.3 Carbon-13 NMR Spectroscopy ...................................................................... 118
4.4 RESULTS AND DISCUSSION: GAS PHASE CHARACTERIZATION ............................... 119
4.4.1 ESI-MS .......................................................................................................... 119
4.5 CONCLUSIONS ........................................................................................................ 120

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CHAPTER 5 CONCLUSION ........................................................................................ 121
5.1 SUMMARY .............................................................................................................. 121
5.1.1 Lead-Amino Acid Complexes ....................................................................... 122
5.1.2 Mercury-Amino Acid Complexes ................................................................. 122
5.1.3 Characterization Techniques .......................................................................... 123
5.2 FUTURE WORK ....................................................................................................... 124
5.2.1 Lead-Amino Acid Complexes ....................................................................... 124
5.2.2 Mercury-Amino Acid Complexes ................................................................. 125
5.2.3 Metal-Biological Molecule Complexes ......................................................... 126
APPENDIX A EXPERIMENTAL PROCEDURES ..................................................... 127
A.1 SAFETY ................................................................................................................. 127
A.2 GENERAL............................................................................................................... 127
A.3 METAL-AMINO ACID COMPLEX PREPARATION AND ISOLATION ........................... 127
A.4 X-RAY CRYSTALLOGRAPHY ................................................................................. 136
A.5 VIBRATIONAL SPECTROSCOPY .............................................................................. 142
A.6 SOLID STATE NMR SPECTROSCOPY ...................................................................... 142
A.6.1 Carbon-13 ssNMR Analyses ......................................................................... 142
A.6.2 Lead-207 ssNMR Analyses .......................................................................... 143
A.7 PH MEASUREMENTS AND PROBE CALIBRATION FOR PD........................................ 144
A.8 SOLUTION STATE NMR SPECTROSCOPY ............................................................... 145
A.8.1 Room Temperature Solutions ....................................................................... 145
A.8.2 Heated Solutions ........................................................................................... 146
A.8.3 Chemical Shift and pD Study for Lead-Valine, L-Valine, and Lead Nitrate
Solutions ................................................................................................................. 146

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A.8.4 Lead-207 Chemical Shift and Lead to Amino Acid Ratio Study for Lead-
Valine and Lead Nitrate Solutions .......................................................................... 146
A.8.5 Chemical Shift and Ionic Strength Study for Lead-Valine, L-Valine, and Lead
Nitrate Solutions ..................................................................................................... 147
A.9 ELECTROSPRAY IONIZATION MASS SPECTROSCOPY ............................................... 147
REFERENCE LIST ........................................................................................................ 148

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LIST OF TABLES
Table 1.1: Worldwide and Domestic (US) Metal Resources. ............................................. 2
Table 1.2: Relative mammalian toxicity of elemental lead and mercury ........................... 4
Table 1.3: Ionization energies of four metals. .................................................................. 13
Table 1.4: Known coordination numbers and van der Waals radii for mercury and lead
............................................................................................................................. 15
Table 1.5: Bond lengths and bond angles of known mercury(I)-carboxylate complexes
............................................................................................................................. 22
Table 1.6: Bond lengths and bond angles of the three methylmercury-amino acid
complexes found in Figure 1.14. ......................................................................... 25
Table 1.7: Mercury-amino acid and lead-amino acid complexes detected in the gas phase
............................................................................................................................. 30
Table 1.8: Properties of mercury and lead. ....................................................................... 32
Table 1.9: Properties of five spin ½ nuclei of interest ..................................................... 35
Table 2.1: Solid state lead-207 NMR data for the five lead-amino acid complexes ........ 67
Table 2.2: Lead-207 chemical shifts of lead nitrate and lead-amino reaction mixtures or
dissolved crystals. ................................................................................................ 78
Table 2.3: Amino acid methine and carboxyl carbon-13 chemical shifts of amino acid
solutions and lead-amino acid solutions .............................................................. 82
Table 2.4: ESI-MS peak assignments of the dissolved crystals and reaction mixtures of
lead-amino acid solutions .................................................................................... 86
Table 3.1: Interatomic distance ranges in [Hg (Ala) (NO ) ]•2H O ............................... 92
12 8 3 8 2
Table 3.2: Solid state carbon-13 NMR chemical shifts (ppm) for crystals of Hg-LAla,
Hg-DAla, and L-alanine.44 ................................................................................... 96
Table 3.3: Carboxyl and methine carbon-13 NMR signals of LAla, HgI+LAla, HgI-LAla,
HgI-DAla, and HgII+LAla. ................................................................................. 104
Table 3.4: ESI-MS data for the reaction mixtures and dissolved crystals of Hg-Ala ..... 107
Table 4.1: Interatomic distances and ranges in Hg-Pro, Hg-NAla, Hg-Ala. .................. 114

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