Quantum chemical investigations of structure, bonding and EPR parameters of manganese complexes relevant to photosystem II [Elektronische Ressource] / vorgelegt von Sandra Schinzel

Sandra B

Sujets

• Physik
• Biologie

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2009
• Nombre de lectures: 15
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

Quantum Chemical Investigations of Structure,
Bonding and EPR Parameters of Manganese
Complexes relevant to Photosystem II


DISSERTATION


zur Erlangung des naturwissenschaftlichen Doktorgrades der
Julius-Maximilians-Universität Würzburg


vorgelegt von
Sandra Schinzel Sandra Schinzel
aus Wertheim, Deutschland


WÜRZBURG 2009














Eingereicht am: _____________________________________
bei der Fakultät für Chemie und Pharmazie


1. Gutachter:
2. Gutachter: _____________________________________
der Dissertation


1. Prüfer:
2. Prüfer: _____________________________________
3. Prüfer:
des Öffentlichen Promotionskolloquiums


Tag des Öffentlichen Promotionskolloquiums: ______________________
Doktorurkunde ausgehändigt am: ________________________________























Contents Contents
1 Introduction ……………………...……………………………………………… 1

2 The Oxygen-Evolving Complex of Photosystem II ……..……………………… 7
2.1 Introduction ……………………………..………………………………… 7
2.2 The Structure of the Oxygen-Evolving Complex ………………………….. 9
2.2.1 Crystallographic Studies …………………………………………………… 9
2.2.2 X-ray Absorption Spectroscopy …………………………….………….... 11
2.2.3 EPR Spectroscopy ……………………………………….……………….. 12
2.3 The Function of Photosystem II ………………………………………….. 14
2.4 Quantum Chemical Studies on the Photosystem II ……..……………….. 16

3 Density-Functional Theory ……………………………………………………. 17
3.1 Introduction ………………………………………………………….…… 17
3.2 Elementary Quantum Chemistry …………………………………………. 18
3.2.1 Schrödinger Equation …………………………………………………….. 18
3.2.2 Solutions for the Schrödinger Equation: The Hartree-Fock
Approximation …………………………………………………………..... 19
3.3 Density-Functional Theory ……………………………………………….. 23
3.3.1 The Hohenberg-Kohn Theorem ………………………………………….. 23
3.3.2 Kohn-Sham Theory ……………………………………………………….. 24
3.3.3 Functionals ………………………………………………………………... 26
3.4 Broken-Symmetry Density-Functional Theory ………...………………… 28
3.4.1 Mapping Schemes for Dinuclear Complexes …………………………….. 29
3.4.2 Corresponding Orbital Transformation and Paired-Orbital Analysis ……. 30

4 Calculation of Electronic Paramagnetic Resonance Parameters ……..………… 33
4.1 Introduction ………………………………………………………………. 33
4.2 Basic Principles ………………………………………………………….. 34
4.3 Experimental Techniques ………………………………………………… 35
4.4 Effective Spin Hamiltonian ………………………………………………. 37
4.5 Spin ……………………………………………………...……………….. 38
IContents
4.6 Perturbation Theory applied to Magnetic Resonance Parameters …...…... 39
4.7 g-Tensor ………………………………………………………..………… 41
4.8 Hyperfine Coupling Constant …..….…………………………...………… 44
4.9 Nuclear Quadrupole Coupling Constant …………..……………………... 45
4.10 Spin-Projection Techniques ……………………………………………… 46
III IV4.10.1 Dinuclear Mn Mn Complexes ……………………………………...….. 46
III IV IV IV4.10.2 Tetranuclear Mn Mn Mn Mn Complexes ……………………..……. 48

5 Electron Paramagnetic Resonance Parameters of Simple Inorganic Mononuclear
Manganese Complexes …………………………………………………………. 51
5.1 Introduction ……………………………………………...……………….. 51
5.2 Computational Details ……………………………………………………. 52
2+5.3 The [Mn(H O) ] Complex …………………………..…………………. 53 2 6
5.3.1 Spin-Density Analysis ………………………………………………….… 53
5.3.2 The g-Tensor ……………………………………………………………… 54
555.3.3 Mn Hyperfine Coupling Constant ………………………………………. 55
15.3.4 H Hyperfine Coupling Constant …………………………………………. 57
175.3.5 O Hyperfine Coupling Constant …………………...…………………… 57
3+5.4 The [Mn(H O) ] Complex ………………………...……………………. 58 2 6
5.5 Other Mononuclear Manganese Complexes ...……………………………. 61
5.6 Conclusions ………………………………………………………………. 63

6 Structure and Electron Paramagnetic Resonance Parameters of the Manganese
Site of Concanavalin A ……………..…………………..…………………….... 65
6.1 Introduction ………………………...…………………………………….. 65
6.2 Computational Details ………………...………………………………….. 67
6.3 Results and Discussion …………………………………………………… 68
6.3.1 Spin-Density Analysis ……………………………………………………. 69
6.3.2 The g-Tensor ……………………………………………………………… 71
556.3.3 Mn Hyperfine Coupling Constant ……………………………………… 72
16.3.4 H Hyperfine Coupling Constants ..………………………….…………… 73
176.3.5 O Hyperfine Coupling Constants …………...…………………………... 76
6.4 Conclusions ………………………………………………………………. 78

IIContents
7 Validation of Broken-Symmetry Density Functional Methods for Electron
III IVParamagnetic Resonance Parameters of Dinuclear Mixed-Valence Mn Mn
Complexes ……………………………………………………………………… 79
7.1 Introduction …………………………………………..………………….. 79
7.2 Computational Details ……………………………………………………. 80
7.3 Model Systems …………………………………………………………… 81
7.4 Results and Discussion …………………………………………………… 83
7.4.1 Structures ………………………………………………………………… 83
7.4.2 Mulliken Spin Densities ………………………………………………….. 85
7.4.3 Paired-Orbital Analysis of Spin Contamination in the BS State …………. 88
7.4.4 Exchange Coupling Constants …………………………………………… 90
7.4.5 g-Tensors 93
557.4.6 Mn Hyperfine Coupling Tensors ………………………………………. 95
557.4.7 Orientation of g- and Mn Hyperfine Tensors ………………………… 100
147.4.8 N Hyperfine Coupling and Nuclear Quadrupole Coupling Tensors ….. 102
17.4.9 H Hyperfine Coupling Tensors ………………………………………. 105
7.5 Conclusions ………………………………………………..………..… 106

8 On the Structure of the Oxygen-Evolving Complex of Photosystem II: Density
Functional Calculations on Electron Paramagnetic Resonance Parameters
of the S State …………………………………………………………………. 109 2
8.1 Introduction ………………………………………………….………….. 109
8.2 Model Systems for the Oxygen-Evolving Complex …………………… 111
+1 +18.2.1 Models Ferreira and Ferreira-2 …………………………………….. 111
+18.2.2 Model Dau …………………………………………………………….. 112
8.2.3 Models Yano ……………………………………………………………. 113
8.3 Computational Details ………………………………………...………… 115
8.4 Results and Discussion ………………………………………………….. 116
8.4.1 Structures and Energies ………………………………………………… 116
8.4.2 Spin-Density and Oxidation-State Distribution and their Dependence on
Coordination Number …………………………………………………… 121
558.4.3 Mn EPR Parameters ………………………………………………….. 123
148.4.4 Histidine N EPR Parameters …………………………………………. 130
8.5 Conclusions ……………………………………………………………... 132
IIIContents
9 Summary ……………………………………………………………………… 135

Zusammenfassung………………………………………………….………….. 139

References ……………………………………………………………………. 143

Appendix A …………………………………………………………………… 155

Appendix B …………………………………………………………………… 165

List of Publications …………………………………………………………… 177

Acknowledgment ……………………………………………………………… 181










IV
Abbreviations Abbreviations
BP Breit-Pauli
BS Broken Symmetry
BS-DFT Broken-Symmetry Density Functional Theory
CW EPR Continous Wave Electron Paramagnetic Resonance
DFT Density Functional Theory
ENDOR Electron Nuclear DOuble Resonance
EPR Electron Paramagnetic Resonance
ESEEM Electron Spin Echo Envelope Modulation
EXAFS Extended X-ray Absorption Fine Structure
HFC HyperFine Coupling
HF-EPR High-Field Electron Paramagnetic Resonance
HS High Spin
MO Molecular Orbital
NO Natural Orbital
NQC Nuclear Quadrupole Coupling
OEC Oxygen-Evolving Complex
PO Paired Orbital
PSII PhotoSystem II
SH Spin Hamiltonian
WOC Water-Oxidizing Cluster
XANES X-ray Absorption Near Edge Structure
XAS X-ray Absorption Spectroscopy
XRD X-ray Diffraction S
ZFS Zero-Field Splitting
V