List of Contributors xv
Preface xvii
1 The Development of Spin-Crossover Research 1
Keith S. Murray
1.1 Introduction 1
1.2 Discrete Clusters of SCO Compounds 4
1.3 1D Chains of FeII SCO Materials 22
1.4 1D Chains of FeIII SCO Materials 28
1.5 2D Sheets of FeII SCO Materials 29
1.6 3D Porous SCO Materials 30
1.7 Some Recent Developments in Mononuclear SCO FeII, FeIII and CoII Compounds 33
1.8 Multifunctional/Hybrid SCO Materials 37
1.9 Developments in Instrumental Methods in Spin-Crossover Measurements 40
1.10 Applications of Molecular Spin-Crossover Compounds 41
1.11 Summary 42
2 Novel Mononuclear Spin-Crossover Complexes 55
Birgit Weber
2.1 Introduction and General Considerations 55
2.2 Novel Coordination Numbers (CN), Coordination Geometries and Metal Centres 57
2.3 Iron Complexes with Novel Ligand Donor Atoms and New Ligand Systems 65
2.4 Other Examples 70
2.5 Conclusion and Outlook 72
3 Spin-Crossover in Discrete Polynuclear Complexes 77
Juan Olguin and Sally Brooker
3.1 Introduction 77
3.2 Dinuclear Iron(II) Complexes 79
3.3 Higher Nuclearity Iron(II) Compounds 98
3.4 Iron(III) 104
3.5 Cobalt(II) 109
3.6 Dinuclear Chromium(II) Complex 111
3.7 Concluding Remarks 112
4 Polymeric Spin-Crossover Materials 121
M. Carmen Munoz and Jose Antonio Real
4.1 Introduction 121
4.2 One-Dimensional SCO-CPs 121
4.3 Two-d = Dimensional SCO-CPs 128
4.4 Three-Dimensional SCO-CPs 133
4.5 Conclusion 138
5 Structure:Function Relationships in Molecular Spin-Crossover Materials 147
Malcolm A. Halcrow
5.1 Introduction 147
5.2 Molecular Shape 150
5.3 Crystal Packing 155
5.4 Cooperativity Mediated by Disorder 158
5.5 Compounds Showing Wide Thermal Hysteresis 158
5.6 Other Noteworthy Compounds 162
5.7 Conclusions 164
6 Charge Transfer-Induced Spin-Transitions in Cyanometallate Materials 171
Kim R. Dunbar, Catalina Achim and Michael Shatruk
6.1 Introduction 171
6.2 Characterization of CTIST Compounds 173
6.3 CTIST in Coordination Polymers 174
6.4 CTIST in Nanoscale Materials 189
6.5 CTIST in Polynuclear Transition Metal Complexes 195
6.6 Summary and Outlook 198
7 Valence Tautomeric Transitions in Cobalt-dioxolene Complexes 203
Colette Boskovic
7.1 Introduction 203
7.2 Induction of Valence Tautomeric Transitions 205
7.3 Other Factors that Contribute to the Valence Tautomeric Transition 210
7.4 Polynuclear Valence Tautomeric Complexes 214
7.5 Bifunctional Valence Tautomeric Complexes 218
7.6 Concluding Remarks 220
8 Reversible Spin Pairing in Crystalline Organic Radicals 225
Jeremy M. Rawson and John J. Hayward
8.1 Introduction 225
8.2 Radical Pairs: Solution and Gas Phase Studies 226
8.3 Dimerisation in the Solid State 229
8.4 Summary and Future Perspectives 234
9 Breathing Crystals from Copper Nitroxyl Complexes 239
Victor Ovcharenko and Elena Bagryanskaya
9.1 Introduction 239
9.2 Structural and Magnetic Anomalies 241
9.3 Relationship Between the Chemical Step and the Physical Property 245
9.4 Relationship Between the Thermally Induced Reorientation of Aromatic Solvate Molecules and the Character of the Magnetic Anomaly 251
9.5 EPR Study of Breathing Crystals 255
9.6 Classification of Spin-Transitions in Breathing Crystals and Correlations with Magnetic Susceptibility 261
9.7 The Detailed Magnetic Structure of Breathing Crystals 266
9.8 EPR-detected LIESST on Breathing Crystals 272
9.9 Conclusion 275
10 Spin-State Switching in Solution 281
Matthew P. Shores, Christina M. Klug and Stephanie R. Fiedler
10.1 Introduction and Scope 281
10.2 Spin-Crossover: Solid State Versus Solution 282
10.3 Practical Considerations 283
10.4 Spin-Crossover in Solution 285
10.5 Ligation Changes Driving Spin-State Switching in Solution 288
10.6 Second Coordination Sphere Triggers for Spin-State Switching 291
10.7 Challenges and Opportunities 294
10.8 Conclusions/Outlook 295
11 Multifunctional Materials Combining Spin-Crossover with Conductivity and Magnetic Ordering 303
Osamu Sato, Zhao-Yang Li, Zi-Shuo Yao, Soonchul Kang and Shinji Kanegawa
11.1 Introduction 303
11.2 Spin-Crossover and Conductivity: Spin-Crossover Conductors 303
11.3 Spin-Crossover and Magnetic Interaction: Spin-Crossover Magnets 308
12 Amphiphilic and Liquid Crystalline Spin-Crossover Complexes 321
Shinya Hayami
12.1 Introduction 321
12.2 Unique Magnetic Properties of SCO Cobalt(II) Compounds with Long Alkyl Chains 322
12.3 Liquid Crystalline SCO Compounds 325
12.4 Langmuir-Blodgett Films and Amphiphilic SCO Compounds 331
12.5 Conclusion and Outlook 339
13 Luminescent Spin-Crossover Materials 347
Helena J. Shepherd, Carlos M. Quintero, G´abor Molnar, Lionel Salmon and Azzedine Bousseksou
13.1 General Introduction 347
13.2 Introduction to Luminescent Materials and Luminescence Energy Transfer 348
13.3 Electronic Transitions and Optical Properties of Spin-Crossover Complexes 358
13.4 Materials with Combined Spin-Crossover and Luminescent Functionalities 361
13.5 Concluding Remarks 371
14 Nanoparticles, Thin Films and Surface Patterns from Spin-Crossover Materials and Electrical Spin State Control 375
Paulo Nuno Martinho, Cyril Rajnak and Mario Ruben
14.1 Introduction 375
14.2 Nanoparticles and Nanocrystals 376
14.3 Thin Films 387
14.4 Surface Patterns 393
14.5 Electrical Spin State Control 396
14.6 Conclusion 399
15 Ultrafast Studies of the Light-Induced Spin Change in Fe(II)-Polypyridine Complexes 405
Majed Chergui
15.1 Introduction 405
15.2 Properties of Fe(II) Complexes 406
15.3 From the Singlet to the Quintet State 408
15.4 Ultrafast X-Ray Studies 415
15.5 Summary and Outlook 417
16 Real-Time Observation of Spin-Transitions by Optical Microscopy 425
Francois Varret, Ahmed Slimani, Damien Garrot, Yann Garcia and Anil D. Naik
16.1 Introduction 425
16.2 Experimental Aspects 426
16.3 Selected Investigations 429
16.4 Conclusions and Prospects 439
17 Theoretical Prediction of Spin-Crossover at the Molecular Level 443
Robert J. Deeth, Christopher M. Handley and Benjamin J. Houghton
17.1 Introduction 443
17.2 Beginnings: Valence Bond and Ligand Field Theories 443
17.3 Quantum Chemistry 446
17.4 Empirical Methods 449
17.5 Conclusions 452
18 Theoretical Descriptions of Spin-Transitions in Bulk Lattices 455
Cristian, Enachescu, Masamichi Nishino and Seiji Miyashita
18.1 Introduction 455
18.2 Elastic Interaction Models for Spin-Crossover Systems 457
18.3 Mechano-Elastic Model 463
18.4 Conclusions 471
19 Optimizing the Stability of Trapped Metastable Spin States 475
Jean-Francois Letard, Guillaume Chastanet, Philippe Guionneau and Cedric Desplanches
19.1 Introduction 475
19.2 Light-Induced Excited Spin-State Trapping (LIESST) Effect 476
19.3 The T(LIESST) Approach: The Case of Mononuclear Compounds 479
19.4 The T(LIESST) Approach: An Extension to Polynuclear Iron(II) Complexes 487
19.5 Simulation and Extrapolation of a T(LIESST) Experiment 495
19.6 Conclusions 500
20 Piezo- and Photo-Crystallography Applied to Spin-Crossover Materials 507
Philippe Guionneau and Eric Collet
20.1 Introduction 507
20.2 Spin-Crossover and Piezo-Crystallography 507
20.3 Crystallography of Photoexcited SCO Materials 512
21 Spin-Transitions in Metal Oxides 527
Jean-Pascal RUEFF
21.1 Introduction 527
21.2 RIXS: A Probe of the 3d Electronic Properties 530
21.3 Experimental Results 533
21.4 Conclusions and Perspectives 538
References 540
Index
