Spin States in Biochemistry and Inorganic Chemistry

It has long been recognized that metal spin states play a central role in the reactivity of important biomolecules, in industrial catalysis and in spin crossover compounds. As the fields of inorganic chemistry and catalysis move towards the use of cheap, non-toxic first row transition metals, it is essential to understand the important role of spin states in influencing molecular structure, bonding and reactivity.

Spin States in Biochemistry and Inorganic Chemistry provides a complete picture on the importance of spin states for reactivity in biochemistry and inorganic chemistry, presenting both theoretical and experimental perspectives. The successes and pitfalls of theoretical methods such as DFT, ligand-field theory and coupled cluster theory are discussed, and these methods are applied in studies throughout the book. Important spectroscopic techniques to determine spin states in transition metal complexes and proteins are explained, and the use of NMR for the analysis of spin densities is described.

Topics covered include:

• DFT and ab initio wavefunction approaches to spin states

• Experimental techniques for determining spin states

• Molecular discovery in spin crossover

• Multiple spin state scenarios in organometallic reactivity and gas phase reactions

• Transition-metal complexes involving redox non-innocent ligands

• Polynuclear iron sulfur clusters

• Molecular magnetism

• NMR analysis of spin densities

This book is a valuable reference for researchers working in bioinorganic and inorganic chemistry, computational chemistry, organometallic chemistry, catalysis, spin-crossover materials, materials science, biophysics and pharmaceutical chemistry.

Auteur

Prof. Dr. Marcel Swart, Universitat de Girona, Spain
Marcel Swart is ICREA Research Professor in the Institute of Computational Chemistry Catalysis at the Universitat de Girona, Spain. He is a computational/theoretical chemist working in the field of (bio)chemistry and biomedicine. He has published >100 papers in peer-reviewed scientific journals and has an h-index of 26. He was awarded the Young Scientist 2005 award by ICCMSE (International Conference of Computational Methods in Sciences and Engineering), and was selected as one of the promising young inorganic chemists of "The next generation" that were invited to contribute to a special issue of Inorganica Chimica Acta in 2007, and to a special issue of Polyhedron in 2010.
In 2012, he was awarded the MGMS Silver Jubilee Prize "for his development of new computational chemistry programs, design of new research tools and application to (bio)chemical systems that are highly relevant for society and science." In September 2012 he organized a CECAM/ESF Workshop on "Spin states in biochemistry and inorganic chemistry", highlighted in Nature Chem. 2013, 5, 7-9.

Prof. Dr. Miquel Costas, Universitat de Girona, Spain
Miquel Costas became Professor Titular at the University of Girona in 2003. He has published over 70 papers in international journals that have received over 3470 citations. His research interests involve the study of transition metal complexes involved in challenging oxidative transformations, including functionalization of C-H bonds and water oxidation. These systems commonly operate in multistate reactivity scenarios, implicating multiple spin states.

Contenu

About the Editors xv

List of Contributors xvii

Foreword xxi

Acknowledgments xxiii

1 General Introduction to Spin States 1
Marcel Swart and Miquel Costas

1.1 Introduction 1

1.2 Experimental Chemistry: Reactivity, Synthesis and Spectroscopy 2

1.3 Computational Chemistry: Quantum Chemistry and Basis Sets 4

2 Application of Density Functional and Density Functional Based Ligand Field Theory to Spin States 7
Claude Daul, Matija Zlatar, Maja Gruden-Pavlovic and Marcel Swart

2.1 Introduction 7

2.2 What Is the Problem with Theory? 9

2.2.1 Density Functional Theory 9

2.2.2 LF Theory: Bridging the Gap Between Experimental and Computational Coordination Chemistry 11

2.3 Validation and Application Studies 15

2.3.1 Use of OPBE, SSB-D and S12g Density Functionals for Spin-State Splittings 17

2.3.2 Application of LF-DFT 21

2.4 Concluding Remarks 25

3 Ab Initio Wavefunction Approaches to Spin States 35
Carmen Sousa and Coen de Graaf

3.1 Introduction and Scope 35

3.2 Wavefunction-Based Methods for Spin States 35

3.2.1 Single Reference Methods 36

3.2.2 Multireference Methods 37

3.2.3 MR Perturbation Theory 39

3.2.4 Variational Approaches 40

3.2.5 Density Matrix Renormalization Group Theory 40

3.3 Spin Crossover 41

3.3.1 Choice of Active Space and Basis Set 41

3.3.2 The HSLS Energy Difference 43

3.3.3 Light-Induced Excited Spin State Trapping (LIESST) 45

3.3.4 Spin Crossover in Other Metals 47

3.4 Magnetic Coupling 47

3.5 Spin States in Biochemical and Biomimetic Systems 50

3.6 Two-State Reactivity 52

3.7 Concluding Remarks 52

4 Experimental Techniques for Determining Spin States 59
Carole Duboc and Marcello Gennari

4.1 Introduction 59

4.2 Magnetic Measurements 61

4.2.1 g-Anisotropy and Zero-Field Splitting (zfs) 64

4.2.2 Unquenched Orbital Moment in the Ground State 64

4.2.3 Exchange Interactions 64

4.2.4 Spin Transitions and Spin Crossover 66

4.3 EPR Spectroscopy 66

4.4 Mössbauer Spectroscopy 70

4.5 X-ray Spectroscopic Techniques 74

4.6 NMR Spectroscopy 77

4.7 Other Techniques 80

4.A Appendix 81

4.A.1 Theoretical Background 81

4.A.2 List of Symbols 82

5 Molecular Discovery in Spin Crossover 85
Robert J. Deeth

5.1 Introduction 85

5.2 Theoretical Background 85

5.2.1 Spin Transition Curves 88

5.2.2 Light-Induced Excited Spin State Trapping 89

5.3 Thermal SCO Systems: Fe(II) 90

5.4 SCO in Non-d6 Systems 93

5.5 Computational Methods 95

5.6 Outlook 98

6 Multiple Spin-State Scenarios in Organometallic Reactivity 103
Wojciech I. Dzik, Wesley Böhmer and Bas de Bruin

6.1 Introduction 103

6.2 "Spin-Forbidden" Reactions and Two-State Reactivity 104

6.3 Spin-State Changes in Transition Metal Complexes 107

6.3.1 Influence of the Spin State on the Kinetics of Ligand Exchange 108

6.3.2 Stoichiometric Bond Making and Breaking Reactions 109

6.3.3 Spin-State Situations Involving Redox-Active Ligands 115

6.4 Spin-State Changes in Catalysis 119

6.4.1 Catalytic (Cyclo)oligomerizations 119

6.4.2 Phillips Cr(II)/SiO2 Catalyst 121

6.4.3 SNSCrCl3 Catalyst 123

6.5 Concluding Remarks 125

7 Principles and Prospects of Spin-States Reactivity in Chemistry and Bioinorganic Chemistry 131
Dandamudi Usharani, Binju Wang, Dina A. Sharon and Sason Shaik

7.1 Introduction 131

7.2 Spin-States Reactivity 132 7.2.1 Two-State and Multi-State Reactivity 133...