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Cover
Editorial
Acknowledgment
1 Introduction to Single‐Molecule Magnets
1. 1.1 What Is a Single‐Molecule Magnet?
2. 1.2 Historical Aspects
3. 1.3 Recent Progress
4. Acknowledgment
5. References
2 Unique Magnetic Properties
1. 2.1 Introduction
2. 2.2 Basic Electromagnetic Definitions
3. 2.3 Magnetostatic Energy (Magnetic Work)
4. 2.4 Thermodynamic Relations
5. 2.5 Definition of ac Magnetic Susceptibility
6. 2.6 Representative Results
7. 2.7 Technical Aspects of the ac Susceptibility Measurements
8. 2.8 Intermolecular Interactions
9. 2.9 Conclusions
10. References
3 Magnetic Modeling of Single‐molecule Magnets
1. 3.1 Introduction
2. 3.2 Atoms in a Magnetic Field
3. 3.3 Magnetic Modeling Tools
4. References
4 Insight into Magnetic and Electronic Properties Through HFEPR Studies
1. 4.1 Introduction: Magnetic vs Electronic Properties of Transition Metal Ions Including SMMs and SIMs
2. 4.2 Basics of HFEPR as Applied to SIMs and Other Transition Metal Complexes
3. 4.3 Applicability of HFEPR to Investigating SMMs and SIMs
4. 4.4 Interplay Between Spin Hamiltonian Parameters and Crystal/Ligand‐Field Parameters. From Simple Ligand Field to Sophisticated Quantum Chemical Calculations
5. Appendix Appendix: National High Magnetic Field Laboratory
6. Acknowledgment
7. References
5 Other Techniques to Study Single‐Molecule Magnets
1. 5.1 Introduction
2. 5.2 The Mössbauer Effect
3. 5.3 The Basic Principles of Mössbauer Spectroscopy
4. 5.4 Hyperfine Interactions
5. 5.5 Relaxation Phenomena and Dynamics
6. 5.6 Application of Mössbauer Spectroscopy to Single‐Molecule Magnets
7. 5.7 Application of Mössbauer Spectroscopy to Single‐Ion Magnets
8. 5.8 Application of Mössbauer Spectroscopy to Fe/4f Single‐Molecule Magnets
9. 5.9 Application of Mössbauer Spectroscopy to Cyanide‐Bridged Complexes
10. 5.10 Other Spectroscopic Techniques Used to Study Iron‐Based SMMs
11. 5.11 Conclusions
12. References
6 Synthesis and Chemistry of Single‐molecule Magnets
1. 6.1 General Introduction for the Synthesis of SMMs and SIMs‐Organization of the Chapter
2. 6.2 Synthetic Aspects for Polynuclear 3d Metal SMMs
3. 6.3 Synthetic Aspects for Dinuclear and Polynuclear 4f Metal Complexes with SMM Properties
4. 6.4 Synthetic Aspects for Dinuclear and Polynuclear Actinide SMMs
5. 6.5 Synthesis of 3d/4f‐, 3d/5f‐, 4f/5f‐Metal and Other Heterometallic SMMs
6. 6.6 Synthesis of 3d Metal SIMs
7. 6.7 Synthetic Methodology for 4f Metal SIMs
8. 6.8 Synthetic Routes for 5f Metal SIMs
9. 6.9 Concluding Comments in Brief–Prognosis for the Future
10. References
7 Breakthrough in Radical‐bridged Single‐molecule Magnets
1. 7.1 General Information About Organic Radicals and Their Magnetic Properties
2. 7.2 3d Metal Radical SMMs
3. 7.3 4f Metal Radical SMMs
4. 7.4 3d–4f Metal Radical SMMs
5. 7.5 5f Metal Radical SMMs
6. 7.6 Conclusions
7. References
8 Assembly of Polynuclear Single‐molecule Magnets
1. 8.1 Introduction
2. 8.2 History
3. 8.3 Topological Methods in Crystal Chemistry and Coordination Chemistry
4. 8.4 Polynuclear Coordination Clusters Assembly and Topology
5. 8.5 3d–4f PCCs
6. 8.6 Assembly Examples and Graph Comparison
7. 8.7 Targeting for New Topologies
8. 8.8 Synthetic Aspects in Recent Examples
9. 8.9 Perspective
10. References
Annexure
1. Chapter 1
2. Chapter 2
3. Chapter 3
4. Chapter 4
5. Chapter 5
6. Chapter 6
7. Chapter 7
8. Chapter 8
9. Hints/Solutions
About the Authors
Index
End User License Agreement

List of Tables

Chapter 03
1. Table 3.1 (L, S)‐multiplets for the carbon atom.
2. Table 3.2 Stevens operators.
3. Table 3.3 Diagonal crystal–field terms.
4. Table 3.4 General information about the rare‐earth ions. The operators are evaluated at T = 0 K while the deviations from spherical symmetry are exaggerated.
5. Table 3.5 Dimensions of the sub‐spaces for the associated spins within the block diagonal form of the HDVV Hamiltonian in a coupled basis for the case of Mn^III ₆.
6. Table 3.6 Comparative table of the anisotropic values of the g and J tensors for the Ce(III) and Fe(III) ions obtained from simulation procedures of the EPR spectra of [CeCo], [LaFe], and [CeFe] dimmers and from the fits of the magnetic data for the [CeFe] system.
Chapter 04
1. Table 4.1 Effect of orbital angular momentum operator, , on real‐valued d orbitals.
Chapter 07
1. Table 7.1 The formulas and U _eff values of metal radical SMMs.
Chapter 08
1. Table 8.1 Representative examples of 3d–4f PCCs (3d = Ni^II, Co^II, Cu^II, Zn^II) supported by Schiff base ligands with a nuclearity ≥5 that display SMM properties.

List of Illustrations

Chapter 01
1. Figure 1.1 Selected milestones in the history of SMMs.
2. Figure 1.2 (A) Molecular structures of the representative SMMs: SMMs of historical importance (a: [Mn₁₂] [39], b: [Fe₈] [41], c: oxime‐bridged [Mn₆] [42], see text). (B) Molecular structures of the representative SMMs: highlights. (a) (left) TbPc₂ [43], (right) [Tb₂N₂]‐core radical‐bridged complex [44], (b) (left) rationally designed [Mn₆Cr] [45], (right) record energy barrier complex [Dy] [32] (see text).
Chapter 02
1. Figure 2.1 Magnetic ellipsoid inside a homogeneous external magnetic field. The external magnetic field is produced by electric current flowing in a solenoid. The external magnetic field magnetizes the ellipsoid, acquiring uniform magnetization M. For homogeneous external field H ₀, inside the ellipsoid, magnetization, magnetic induction, and magnetic field are homogeneous vector fields. The total magnetic field inside the ellipsoid will be given by H _in = H ₀ + H _d , where H _d = − [n]M is the demagnetization field, and [n] is the demagnetization tensor. The demagnetization field of the external magnetic field and can be assumed that it arises from the effective surface magnetic poles density.
2. Figure 2.2 The hatched area represents the energy for establishing the magnetic induction B and the magnetization for a material.
3. Figure 2.3 Variation with time of the magnetization for a sample with relaxation time in a sudden change of the magnetic field.
4. Figure 2.4 Variation with ωτ the normalized real and imaginary parts of the fundamental magnetic ac susceptibility. In left(right) panel the x‐axis is linear (log₁₀), respectively.
5. Figure 2.5 Cole–Cole diagram (or Argand diagram) displaying the χ″/χ _T as a function of χ′/χ _T .
6. Figure 2.6 Variation of the ratio M/χ _T H ₀ vs. H/H ₀ for a period for a paramagnetic system that is described from a Debye relaxation model. Shown are the magnetization loops for characteristic values of the parameter ωτ .
7. Figure 2.7 Variation of the real and imaginary part of the ac susceptibility as a function of the parameter ωτ for a paramagnetic system that is described from the Debye relaxation model with nonzero adiabatic susceptibility.
8. Figure 2.8 Argand diagram for a Debye model of the magnetic ac susceptibility model. Variation of the χ″/χ _T as a function of χ′/χ _T for χ _S/χ _T = 0.2.
9. Figure 2.9 Variation with ωτ the normalized real and imaginary parts of the fundamental ac susceptibility for χ _S/χ _T = 0, 0.1, γ = 0, 0.2, and 0.7.
10. Figure 2.10 Argand diagram with nonzero adiabatic susceptibility and Cole–Cole type distribution of the relaxation times. Variation of the χ″/χ _T as a function of χ′/χ _T for γ = 0.2 and χ _S/χ _T = 0.2.
11. Figure 2.11 Real and imaginary ac susceptibility as a function of the dc – magnetic field and frequency of Fe(acac)₃.
12. Figure 2.12 Analysis of the ac susceptibility measurements of Fe(acac)₃. (top left) Isothermal dc magnetization as function of the dc magnetic field measured at T = 5 K. (top right) Variation with the dc magnetic field of the isothermal and adiabatic susceptibility at T = 5 K. (bottom) Argand diagram of the ac‐susceptibility measurements in several dc magnetic fields.
13. Figure 2.13 Relaxation time as function of temperature for Fe(acac)₃ in several dc magnetic fields.
14. Figure 2.14 (a) χT and χ″ vs T data for [Mn^III ₆] and (b) [Mn^III ₆]_n at various temperatures.
15. Figure 2.15 (a) Temperature dependence of parameter γ for [Mn^III ₆] and [Mn^III ₆]_n. (b) Temperature dependence of ln(τ) for [Mn^III ₆]_n and [Mn^III ₆].
16. Figure 2.16 Variation of ln(χ″/χ′) as a function of 1/T compound [Mn^III ₆]_n measured in the indicated frequencies.
17. Figure 2.17 Variation of ln(χ″/χ′) as a function of 1/T compound [Mn^III ₆] measured in the indicated frequencies.
18. Figure 2.18 Variation of ln(τ) with 1/T of [Bu₄N]₂[Cu₃(μ₃‐Cl)₂(μ‐pz)₃Cl₃]. The ac susceptibility data are measured at 0.5, 2, 5, and 10 kOe dc magnetic field. Solid lines in the upper panel are a guide to the eye.
19. Figure 2.19 Temperature variation of the parameter γ for [Bu₄N]₂[Cu₃(μ₃‐Cl)₂(μ‐pz)₃Cl₃].
20. Figure 2.20 Hartshorn bridge used to measure the ac susceptibility. It consists of two oppositely wound coils, used to detect the electromotive force induced from the change of the magnetic flux, produced from the sample magnetization. The sample is magnetized by an external dc and ac magnetic field produced by the corresponding coils.
Chapter 03
1. Figure 3.1 The vector model of the atom, showing both the magnetic moment and the angular momentum. m precesses rapidly around J, and the time‐averaged moment then precesses around Oz.
2. Figure 3.2 Energy spectrum for a carbon atom with a ³P ground state. This multiplet is further split by a weak spin–orbit coupling into states with different J quantum number ( J = 0, 1, 2).
3. Figure 3.3 Crystal structure of the inverse‐[9‐MC‐3] metallacrown [Mn₆(O)₂(dicl)₂(sao)₆(CH₃OH)₆ where dicl stands for the nonsteroidal anti‐inflammatory drug (NSAID), dicllofenac. Salicylaldoxime (H₂sao) acts as a bifunctional ligand providing the nitrogen and the oxygen atoms for the formation of the metallacrown ring (open gray stick: N, black stick: O). The doubly deprotonated ligand of salicylaldoxime (sao²⁻) is a potentially tridentate binucleating ligand, which may be coordinated to the metal ions via its nitrogen and oxygen atoms participating thus in the formation of the metallacrown ring.
4. Figure 3.4 Temperature dependence of the susceptibility data of compound 1 (solid spheres) and fitting results (solid line) using the software PHI v3.0 according to the 3‐J magnetic model described in the same figure.
5. Figure 3.5 Temperature dependence of the susceptibility data of compound 1 (solid spheres) and fitting results (solid line) using the software PHI v3.0 according to the 3‐J magnetic model described in the same figure.
6. Figure 3.6 Dimers of the general formula [Ln(H₂O)₃(dmf)₄(μ‐CN)M(CN)₅] ⋅ nH₂O (5) where 1 ≤ n ≤ 1,5, dmf = N,N′‐dimethylformamide and M = Fe(III), Co(III) and Ln(III) = Ce(III), La(III).
7. Figure 3.7 General overview of the second approach (a) the X‐band EPR study of the spectra of the isostructural [LaFe] and [CeCo] systems – where the La(III) and Co(III) are diamagnetic ions and will give the effective g‐values of the Ce(III) and Fe(III) ions; (b) using the above derived g‐values, a fitting procedure of the susceptibility data (<50 K) as well as the magnetization data of the [CeFe] dimer will give the anisotropic exchange constants; (c) using the above derived g‐values, and the same anisotropic exchange model simulations of the EPR spectra of the [CeFe] dimer in both the parallel and the perpendicular model will give the anisotropic exchange constants to be compared with the results of the (b) step.
8. Figure 3.8 2D‐Lattice with finite size (L,W) = (5,3) created by translation of the unit cell (black rectangular) five times in L direction and three times in W direction.
9. Figure 3.9 Input file for the Lattice description of a 0‐D magnetic molecule with multispin magnetic centers and three different exchange interaction couplings.
10. Figure 3.10 Input file for the MODEL description of a 0‐D magnetic molecule with multispin magnetic centers and three different exchange interaction couplings.
11. Figure 3.11 Description of the BASIS term inside the MODEL's input file of a 0‐D magnetic molecule with multispin magnetic centers and three different exchange interaction couplings.
12. Figure 3.12 General overview of the input structure in a QMC simulation of the ALPS project.
13. Figure 3.13 Structure of the heterometallic molecular wheel Mn₆Fe₆.
14. Figure 3.14 Temperature dependence of χ _M T for (6–10). The solid lines represent the QMC simulations (2–300 K) according to the theoretical model discussed in the text.
15. Figure 3.15 Magnetic model of compound Cu₂₁ with 3‐J Hamiltonian formalism. See text for details.
16. Figure 3.16 Magnetic model of compound Cu16 with 2‐J Hamiltonian formalism. See text for details.
17. Figure 3.17 Magnetic model of compound Cu16 (solid cycles) and Cu21 (solid stars) with 2‐J/3‐J Hamiltonian model. The solid lines are the results from the QMC simulation process.
18. Figure 3.18 (a) Magnetic model of multivalence molecular wheel Mn^III ₆Mn^II ₆ showing the six different exchange interactions. (b) Spin configuration according to the origin of the exchange interactions. (S ₄ = S ₆ = S ₂ = S ₈ = S ₁₀ = S ₁₂ = 5/2), (S ₁ = S ₃ = S ₅ = S ₇ = S ₉ = S ₁₁ = 2).
19. Figure 3.19 (a) The crystal structure (stellated cuboctahedron) looking down through a triangular window of compound (15). All the 24 Fe^II _LS diamagnetic ions have been omitted for clarity reasons and the black spheres represent the HS Fe^III magnetic ions. (b) The magnetic model according to the Hamiltonian formalism presented in Eq. 3.94.
Chapter 04
1. Figure 4.1 (a) Polycrystalline powder HFEPR spectra of Mn₁₂Ac at 245 GHz at different temperatures. The narrow signal is given by DPPH (g = 2.0037). (b) Magnetization hysteresis loops in a single crystal of Mn₁₂Ac at indicated temperatures.
2. Figure 4.2 (a) Energy levels of the S = 10 spin state for magnetic field in the hard plane (xy) of the ZFS tensor. The bars indicate allowed EPR transitions between the M _S states responsible for the progression of resonances in the high field region of Figure 4.1. (b) A powder‐pattern simulation (including both perpendicular, and parallel turning points) of the spectrum shown in Figure 4.1 at 20 K. In both cases, the simulation parameters (up to fourth‐order ZFS) were taken from Barra et al. [5]. The higher‐than‐second‐order ZFS terms are responsible for the uneven spread of turning points.
3. Figure 4.3 Effect of spin Hamiltonian (Eq. 4.2) acting on the wavefunctions of the simplest high‐spin Kramers (S = 3/2, left) and non‐Kramers (S = 1, right) states. The result is a splitting of the S levels into spin sublevels characterized by the M _S quantum numbers. The ZFS parameters were chosen as: D = −15 cm⁻¹, |E| = 2.5 cm⁻¹ (|E/D| = 1/6) for S = 3/2 and D = −30 cm⁻¹, |E| = 5 cm⁻¹ (|E/D| = 1/6) for S = 1. Note that the ZFS for S = 3/2 is roughly 2D, while it is D for S = 1 (each with E ≪ D); hence, the magnitude of D in the former case is half that of the latter so that the two are on approximately the same energy scale. The arrows represent possible EPR transitions between the spin sublevels in zero field.
4. Figure 4.4 Effect of spin Hamiltonian (Eq. 4.2) acting on the wavefunction of the simplest high‐spin Kramers (S = 3/2, left) and non‐Kramers (S = 1, right) states. The magnetic field was chosen to be oriented parallel to the z‐axis of the ZFS tensor. Both zero‐field and high‐field M _S levels are indicated. Analogously to Figure 4.3, the ZFS parameters are: D = −15 cm⁻¹, |E| = 2.5 cm⁻¹ (|E/D| = 1/6) for S = 3/2 and D = −30 cm⁻¹, |E| = 5 cm⁻¹ (|E/D| = 1/6) for S = 1, along with isotropic g = 2.00. The long arrows represent a quantum energy carried by radiation of 1 THz frequency (33.3 cm⁻¹) and point out EPR transitions expected in such conditions (neglecting the Boltzmann effect on the populations of the given levels). The short bars indicate a 10 times smaller quantum energy carried by radiation of 100 GHz frequency (3.33 cm⁻¹). One can see that in the case of S = 3/2 only intra‐Kramers transitions are possible at 100 GHz in relatively low fields, while only inter‐Kramers transition will occur near 28 T. In the case of S = 1, the only transition will also occur near the same very high field value. This illustrates the need for both high frequencies and fields in HFEPR experiments.
5. Figure 4.5 HFEPR spectrum of a Mn^III complex (S = 2) with SIM properties Ph₄P[Mn(opbaCl₂)(py)₂] (H₄opbaCl₂ = N,N′‐3,4‐dichloro‐o‐phenylenebis(oxamic acid), py = pyridine, and Ph₄P⁺ = tetraphenylphosphonium cation), recorded at 333.6 GHz and 10 K. Black trace: experiment. Colored traces: powder‐pattern simulations using best‐fitted spin Hamiltonian parameters: D = −3.421(2) cm⁻¹, E = −0.152(2) cm⁻¹, B ⁴ ₀ = B ⁴ ₂ = 0, B ⁴ ₄ = 32(5) × 10⁻⁴ cm⁻¹, g = [1.994(2), 1.997(2), 1.978(7)]. Blue trace: negative ZFS; red trace: positive ZFS. The appearance of multiple resonances in the high‐field region of the experimental spectrum is an unambiguous indication of the negative sign of D. Source: Adapted from Vallejo et al. 2013 [17]. Copyright 2013, Reproduced with permission of John Wiley & Sons.
6. Figure 4.6 Two‐dimensional map of HFEPR turning points in a pellet of the same Mn^III complex as in Figure 4.5. The squares are experimental resonances while the curves were simulated using the same spin Hamiltonian parameters as in Figure 4.5. Red curves: turning points with B ₀||x, blue curves: B ₀||y, black curves: B ₀||z, and green curves: off‐axis turning points. Only most prominent off‐axis turning points are shown (several lesser turning points also show up at certain frequencies in the spectra). The dashed vertical line indicates the frequency/energy (333.6 GHz/11.12 cm⁻¹) at which the spectrum shown in Figure 4.5 was recorded.
7. Figure 4.7 (a) 406 GHz EPR spectrum of [Ni₂(sym‐hmp)₂](BPh₄)₂·3.5DMF·0.5(2‐PrOH), where (sym‐hmp)⁻ is 2,6‐bis[(2‐hydroxyethyl)methylaminomethyl]‐4‐methylphenolate anion, at 40 K (black trace) accompanied by a powder‐pattern simulation for S = 1 (red trace). (b) A two‐dimensional map (magnetic field vs frequency or energy of the sub‐THz wave quantum) of the same complex at 40 K (squares) and its simulations using best‐fitted spin Hamiltonian parameters. Red traces: turning points with B ₀ parallel to the x axis of the ZFS tensor; blue traces: B ₀||y; black traces: B ₀||z.
8. Figure 4.8 Correlation diagram between the weak field (left side) and strong field (right side) terms for a d² ion in tetrahedral (T _d) point group symmetry. The free‐ion terms are given on the far left and the (infinitely) strong field terms on the far right. The energy spacing is qualitative. Crossing of states of the same symmetry and multiplicity is not allowed. The lowest energy triplet excited state, ³T₂, can be seen on the middle far right and this state is what is primarily considered in the second‐order perturbation theory calculation of ZFS.
9. Figure 4.9 Effect on the triplet electronic states of a tetrahedral d² complex upon tetragonal compression. The relative energies are not to scale, but the ordering is what would result upon addition of a tetragonal crystal field splitting Dt < 0 (|Dt| ≪ |Dq|). The free‐ion and strong‐field designations are also given for correspondence with Figure 4.8, although these are oversimplifications as the states are not pure.
10. Figure 4.10 National High Magnetic Field Laboratory, Tallahassee, FL, USA.
Chapter 05
1. Figure 5.1 Decay of the ⁵⁷Co nucleus.
2. Figure 5.2 Emission and absorption profiles from a nucleus and the presence of recoil.
3. Figure 5.3 Mössbauer spectra and the effect of hyperfine parameters.
4. Figure 5.4 (a) The molecular structure of form 1 of (Mes₂ArCO₂)₃Fe₂(OCHMe₂)₂. (b) The molecular structure of form 2 of (Mes₂ArCO₂)₃Fe₂(OCHMe₂)₂ [15].
5. Scheme 5.1 The ligands used in Fe^III and Fe^II SMMs.
6. Figure 5.5 The molecular structure of the cation [Fe₈O₂(OH)₁₂(tacn)₆]⁸⁺, the first iron(III) single‐molecule magnet. Color code: Fe octant, O dark gray, N light gray, C large white, H small white [17].
7. Figure 5.6 The molecular structure of the anion [Fe^III ₁₃O₄F₂₄(OMe)₁₂]⁵⁻. Color code: Fe octant, O dark gray, F light gray, C large white [22].
8. Figure 5.7 The molecular structure of the cation [Fe^III ₁₁O₇(dea)₃(piv)₁₂]⁺. Color code: Fe octant, O dark gray, N light gray, C large white [24].
9. Figure 5.8 The molecular structure of [HFe^III ₁₉O₁₄(OEt)₃₀]. Color code: Fe octant, O dark gray, N light gray, C large white. The bonds around µ₆‐O and µ₃‐O groups are shown as black and gray respectively [25].
10. Figure 5.9 The molecular structure of [Fe^III ₄(OMe)₆(dpm)₆]. Color code: Fe octant, O dark gray, C white [26].
11. Figure 5.10 The molecular structure of {Fe^III[Fe^III(L¹)₂]₃}. Color code: Fe octant, O dark gray, N light gray, C white [28].
12. Figure 5.11 The molecular structure of [Fe^II ₂(acpypentO)(NCO)₃]. Color code: Fe octant, O dark gray, N light gray, C white [29].
13. Figure 5.12 The molecular structure of [Fe^II ₉(N₃)₂(O₂CMe)₈{(2‐py)₂CO₂}₄]. Color code: Fe octant, O dark gray, N light gray, C white [32].
14. Figure 5.13 The molecular structure of the cation [Fe^II ₇(OMe)₆(Hbmsae)₆]²⁺. Color code: Fe octant, O dark gray, N light gray, C small white, Br large white [34].
15. Figure 5.14 The molecular structure of the cation [Fe^IIFe^III(L)(O₂CMe)₂]⁺. Color code: Fe octant, O dark gray, N light gray, C small white [35].
16. Figure 5.15 The molecular structure of one of the crystallographically independent cations [(Me₃TpyA)₂Fe^II ₂(L)]²⁺ in the structure of [Fe^II ₂] SMM. Color code: Fe octant, O dark gray, N light gray, C small white, Br large white [36].
17. Figure 5.16 The molecular structure of the anion [(^tbsL)Fe₃]⁻ in the mixed‐valence [Fe₃] SMM. Color code: Fe octant, O dark gray, N light gray, C small white, Si large white [37].
18. Scheme 5.2 Some of the ligands used in mononuclear iron SMMs.
19. Figure 5.17 The molecular structure of the anion [Fe^II(tpa^t‐Bu)]⁻ in Fe^II‐1. Color code: Fe octant, N gray, C white [39].
20. Figure 5.18 The molecular structure of the anion [Fe^I{C(SiMe₃)₃}₂]⁻. Color code: Fe octant, C white, Si gray [40].
21. Figure 5.19 The molecular structure of [Fe^II{C(SiMe₃)₃}₂]. Color code: Fe octant, C white, Si gray [44].
22. Figure 5.20 The molecular structure of [Fe^II{N(SiMe₃)(Dipp)}₂]. Color code: Fe octant, N gray, C small white, Si large white [48].
23. Figure 5.21 The molecular structure of [Fe^II{OC₆H₃‐2,6‐(C₆H₃‐ⁱPr₂)₂}₂]. Color code: Fe octant, O dark gray, C white. Dashed lines define the weak secondary interaction Fe–C = 2.765(3) Å [48].
24. Figure 5.22 The molecular structure of [Fe^I(cAAC)₂Cl]. Color code: Fe octant, N small gray, C white, Cl large dark gray [54].
25. Figure 5.23 The molecular structure of the cation [Fe^I(cAAC)₂]⁺. Color code: Fe octant, N gray, C white [54].
26. Figure 5.24 The molecular structure of the anion [Fe^I{N(SiMe₃)₃}₂]⁻ in Fe^I‐1. Color code: Fe octant, N gray, C small white, Si large white [55].
27. Figure 5.25 The molecular structure of one of the crystallographically independent molecules in the crystal structure of [Fe^II(Eind)₂]. Color code: Fe octant, C white [56].
28. Scheme 5.3 The aminoalcohol ligands used in Fe/4f SMMs.
29. Figure 5.26 The molecular structure of the saddle‐up ring [Fe^III ₄Dy^III ₄(teaH)₈(N₃)₈(H₂O)] ⋅ H₂O. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [57].
30. Figure 5.27 The molecular structure of [Fe^III ₂Dy^III ₂(OH)₂(teaH)₂(O₂CCPh)₆]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [58].
31. Figure 5.28 The molecular structure of [Fe^III ₄Dy^III ₂(teaH)₄(N₃)₇(piv)₃]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [59].
32. Figure 5.29 The molecular structure of [Fe^III ₄Dy^III ₂(OH)₂(n‐bdea)₄(C₆H₅CO₂)₈]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [60].
33. Figure 5.30 The molecular structure of [Fe^III ₄Dy^III ₂(OH)₂(n‐bdea)₄((CH₃)₃CCO₂)₆(N₃)₂]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [61].
34. Figure 5.31 The molecular structure of [Fe₇Dy₃(µ₄‐O)₂(µ₃‐OH)₂(mdea)₇(µ‐benzoate)₄(N₃)₆]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [62].
35. Figure 5.32 The molecular structure of [Fe₄Dy₂(µ₄‐O)₂(NO₃)₂(piv)₆(Hedte)₂]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [64].
36. Figure 5.33 The molecular structure of [Fe^III ₂Dy₂(µ₃‐OH)₂(teg)₂(N₃)₂(C₆H₅CO₂)₄]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [65].
37. Figure 5.34 The molecular structure of [Fe^III ₂Dy₂(µ₃‐OH)₂(pmide)₂(p‐Me‐C₆H₅CO₂)₆]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [66].
38. Scheme 5.4 The Schiff base and reduced Schiff base ligands used in Fe/4f SMMs.
39. Figure 5.35 The molecular structure of [Fe^III ₂Dy^III ₂(OH)₂(L¹)₂(HL²)₂(NO₃)₄(H₂O)_1.5(MeOH)_0.5]. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [67].
40. Figure 5.36 The molecular structure of [Fe^III ₂Dy₂(H₂L)₄(NO₃)₂]²⁺. Color code: Fe white octant, Dy gray octant, O dark gray, N light gray, C white [68].
41. Figure 5.37 The molecular structure of [Fe^III ₃Dy(µ₃‐O)₂(CCl₃CO₂)₈(H₂O)(thf)₃]. Color code: Fe white octant, Dy gray octant, O dark gray, Cl light gray, C white [69].
42. Figure 5.38 The molecular structure of [Fe^II ₂Dy(L)₂(H₂O)]²⁺. Color code: Fe white octant, Dy gray octant, O dark gray, N small light gray, Cl large light gray, C white [71].
43. Figure 5.39 The molecular structure of the cation [(talen^t‐Bu ₂)(Mn^III(MeOH))₃}₂{Fe^III(CN)₆}]³⁺ (Fe–C–N–Mn bonds are shown in black). Color code: Fe white octant, Mn gray octant, O dark gray, N small light gray, Cl large light gray, C white [76].
Chapter 06
1. Figure 6.1 The organic ligand 3‐carboxy‐5‐chlorosalicylaldehyde used for the synthesis of a recently reported [15] field‐induced Cu^II ₄ SMM.
2. Figure 6.2 The crystallographically established coordination modes of the exclusively EO‐bridging azido groups and the Harris notation that describes these modes; M is a 3d metal ion.
3. Figure 6.3 Selected ligands and families of ligands, which have been used for the synthesis of 3d metal SMMs. R, R′ are usually simple non‐donor groups (e.g. H, Me, Et, Ph, …), but they can also be simple (e.g. NH₂) or more complicated donor groups; n = 1, 2.
4. Figure 6.4 The structure of a molecule of cluster 4 in the crystal. Colors: Ni, green; O, red; N, blue; Cl, purple; C, gray. H atoms have been omitted for clarity.
5. Figure 6.5 The structure of the cation of cluster 6 in the crystal.
6. Figure 6.6 The cores of the “normal” Mn₁₂ clusters (a) and the anion of 9 (b).
7. Figure 6.7 Simplified spin coupling scheme for 14 and 15. X, Y, Z are N atoms in the case of 14; X, Y, Z are N, C, and O atoms, in the case of 15. The dashed lines do not represent bonds but they are used to illustrate the metal topology, which can be described as two square pyramids sharing a common apex.
8. Figure 6.8 Fumaric acid (fumH₂) and 1,3‐di(pyridine‐2‐yl)propane‐1,3‐dione dioxime (dpdH₂) used in reactions with 16 for its programmed aggregation.
9. Figure 6.9 Selected organic ligands and families of ligands, which have been used for the synthesis of dinuclear and polynuclear 4f‐metal SMMs. R=H, OEt, OⁿBu, CN,…
10. Figure 6.10 Schematic diagram of the molecular structure of [Dy₂Cl₂(Cp)₄] (37). Filled circles, Dy^III; empty circles, carbon; H atoms have been omitted for clarity.
11. Figure 6.11 Schematic diagrams of the molecular structures of [Dy₂(bta)₂(Cp)₄] (39) and [Dy₂{N(H)pmMe₂}₂(Cp)₄] (40).
12. Figure 6.12 A schematic diagram of the molecular structure of complexes [KLn₂(C₇H₇){N(SiMe₃)₂}₄], where Ln = Dy (44) and Er (45).
13. Figure 6.13 A schematic diagram of the molecular structures of the [Ln₂(N₂){(NSiMe₃)₂}₄(THF)₂] (47) complexes.
14. Figure 6.14 General schematic structural type for the mixed‐ligand triple‐decker complexes 51; M = M′ = Tb (51a), M = Y and M′ = Tb (51b), M = Tb and M′ = Y (51c), and M = M′ = Y (51d). The donor atoms are the ring N atoms of the phthalocyaninato ligands.
15. Figure 6.15 Schematic structure of 55.
16. Figure 6.16 Schematic structure of 56.
17. Figure 6.17 Schematic structure of the mononuclear octahedral metalloligand 57.
18. Figure 6.18 Schematic structures of the molecules that are present in the families of compounds 58 and 60, and of the cations that are present in the family 59. N^⌒N‐OH and N^⌒N‐O⁻ represent the mpkoH and mpko^‐ ligands, respectively.
19. Scheme 6.19 Few selected ligands and families of ligands, which have been used for the synthesis of 3d/4f‐metal clusters, including SMMs. R and R″ are usually hydrogen and non‐donor or donor carbon‐based groups, while R′ can be H, Cl, Br, NO₂,…
20. Figure 6.20 Schematic structure of complex 62. The artwork containing the three N atoms and the two O atoms represents the bpca⁻ ligand.
21. Figure 6.21 Schematic structure of the 3d/5f‐metal wheel 64.
22. Figure 6.22 Schematic structures of the tetranuclear molecules that belong to family 65. N^⌒N^⌒N^⌒N^⌒N^⌒N^⌒N^⌒N represents the tetra‐anionic “Pacman” ligand.
23. Figure 6.23 Schematic structure of the pentanuclear cation that is present in complex 67a. N^⌒N^⌒N^⌒N^⌒N represents the pentadentate chelating ligand PY5Me₂.
24. Figure 6.24 Schematic structures of the anions that are present in complexes 68 (M = Os, Ru, Fe, Co). O^⌒N^⌒N^⌒O represents the dianionic Schiff base H₂salphen.
25. Figure 6.25 Structural formula of the ligand crypt‐222 (a), schematic structure of the anion [Fe^I{C(SiMe₃)₃}₂]⁻ that is present in complex 69b (b), and the orbital scheme for the seven 3d electrons of 69b (c) that is the origin of a strong magnetic moment along the z direction.
26. Figure 6.26 Non‐phthalocyanine ligands used in the chemistry of 4f metal SIMs.
27. Figure 6.27 Schematic drawing of the structure of [Dy(BIPM^TMS)₂]⁻ in the salt 87.
28. Figure 6.28 The schematic molecular structures of 89 (a) and of the cation of salt 88 (b).
29. Figure 6.29 Ligands used in the preparation of 5f metal SIMs. Ligand D is the same with ligand F in Figure 6.26.
30. Figure 6.30 Schematic drawing of the molecular structure of 98.
31. Figure 6.31 Schematic general molecular structures of salts 99 (M = Na, K, Rb, Cs) and neutral compounds 100 (M = Li, Na, K, Rb, Cs). For 99 the crown is 12C4 for Na, 15C5 for K, B15C5 for Rb, and B15C5 for Cs (B = benzo). For 100 the crown′ is 12C4 for Li, 15C5 for Na, DB18C6 for K, 18C6 for Rb, and 18C6 for Cs (DB = dibenzo). C is the general abbreviation for crown ethers; the left number indicates the number of O atoms. For example, DB18C6 is dibenzo‐18‐crown‐6 and 12C4 is 12‐crown‐4.
Chapter 07
1. Scheme 7.1 Representations of the Plus (P) and Minus (M) enantiomeric forms of the PTM radical.
2. Scheme 7.2 Representative nitroxide radicals.
3. Figure 7.1 (a) The molecular structure of 1 and (b) the χ _M T vs T plot for the same compound.
4. Scheme 7.3 Representative carbene radicals.
5. Figure 7.2 (a) The molecular structures of 11 and (b) 18.
6. Scheme 7.4 Benzosemiquinonoid and nindigo radicals.
7. Figure 7.3 (a) The molecular structure of 21 and (b) the χ _M T vs T plots for 21 (top) and 21A (bottom).
8. Figure 7.4 A general representation of the double‐decker molecular structures of the [Ln(Pc)₂] radical species.
9. Scheme 7.5 Representative phthalocyanine, Pc, ligands.
10. Figure 7.5 (a) The χ_M′T vs T plots for 25 and (b) 26.
11. Figure 7.6 (a) Hysteresis loops of the (27) normalized MCD intensity for 27A, (b) 27, and (c) 27B at 1.8–1.9 K and at a sweep rate of 1 T min⁻¹.
12. Figure 7.7 (a) A representation of the molecular structure of 31 and (b) 32.
13. Figure 7.8 A representation of the molecular structure of 36.
14. Figure 7.9 (A) A representation of the molecular structure of 37 and the χ_M′ vs (B) T plot for the same compound.
15. Figure 7.10 A representation of the molecular structure of 38.
16. Figure 7.11 A representation of the molecular structure of 42–45.
17. Figure 7.12 A representation of the molecular structure of compound 48.
18. Scheme 7.6 The N₂ ³⁻ radical ligand.
19. Figure 7.13 A representation of the molecular structure of compound 50.
20. Scheme 7.7 (a) Representation of the bpym and (b) tppz radical ligands.
21. Figure 7.14 (a) A representation of the molecular structure of compound 52 and (b) the χ_M″ vs ν plot for the same compound.
22. Figure 7.15 A representation of the molecular structure of compound 53.
23. Scheme 7.8 Representation of the HvdpyCH₂OH²⁻ verdazyl radical.
24. Figure 7.16 (a) The reduced form of 2,2′‐bpy ligand and (b) the molecular structure of 56.
Chapter 08
1. Scheme 8.1 A mind‐map summarizing this chapter.
2. Figure 8.1 (a) Molecular structure of 1; color code: Mn^III, purple; Mn^IV, blue; O, red; C, white; hydrogen ions omitted for clarity. (b) The graphical interpretation of Mn ₁₂ ‐OAc enumerated as 3,4,6M12‐1. Purple and blue spheres corresponds to nodes not to metal centers.
3. Figure 8.2 Crystal structure of [(μ₅‐dcp)‐(μ₄‐dcp)‐CuDy₂(μ₄‐SO₄)(H₂O)₃] ⋅ H₂O; dcp = 3,5‐dicarboxylatopyrazolyl (COWWIV) [3]: (a) the structural motif with a selected “bridged” chain representation of the Cu₂Dy₄ coordination cluster skeleton; (b) the underlying net of the “standard” representation (ZA = dcp; ZB = H₂O; ZC = SO₄; ZD = Cu; ZE = Dy); (c) the “skeleton” representation and (d) the coordination modes of the dcp and sulfate ligands.
4. Figure 8.3 Molecular structure of the 3d–4f PCCs Zn^II ₆Dy^III ₂₄ [25]. Color code: Dy^III, light blue; Zn^II, gray; O, red; N, pale blue; C, white; S, sulfur.
5. Scheme 8.2 Coordination modes of pivalate ion in descending order of their occurrence.
6. Figure 8.4 Molecular structure of Cu^II ₂Tb^II ₂ reported by Osa [61, 62]. Color code: Dy^III, light blue; Cu^II, blue; O, red; N, pale blue; C, white; F, green.
7. Figure 8.5 The most abundant type of high‐nuclearity 3d–4f PCC skeleton 1,5M6‐1.
8. Figure 8.6 (a) The 1,1,2,4,5M10‐1, (b) 2,3,4,4M10‐1, and (c) 2,3,3,5,5,7M10‐1 motifs, and (d) the 2,3,4M6‐1 motif for eye catching and comparison purposes.
9. Scheme 8.3 Protonated forms of ligands used for the construction of PCCs described in this chapter.
10. Figure 8.7 (left) The protonated form of H₂ L34 ligand used for the synthesis of 4 (middle) The protonated form of H₂ L17 ligand used for the synthesis of 5 (right) the 3,6 M9–1 topology.
11. Figure 8.8 (left) Molecular structure of 8. Color code: Ln^III, light blue; Ni^II, green; C, white; N, pale blue; O, red; F, purple; S, yellow. (Right) Observed 3,6M7‐1 topology for 8. The electronic version contains the colored version.
12. Figure 8.9 Observed configurations of 3d and 4f ions in the 3,6M7‐1 topology.
13. Scheme 8.4 The protonated forms of the ligands, used in the synthesis of compounds 9 and 12 (H₂ L16), 10 (H₂ L43), and 11 (H₂ L44).
14. Figure 8.10 (a) Molecular structure of compound 9. Color code: Ln^III, light blue; Co^II, pink; C, white; N, pale blue; O, red; Cl, green. Hydrogens omitted for clarity. (b) Topological representation of the 2,3,4M6‐1 topology observed in 9 and 10.
15. Scheme 8.5 The protonated forms of the ligands, used in the synthesis of compounds 13 (H₂ L45), 14 (H₂ L12), and 15 (H₂ L11).
16. Figure 8.11 Observed configurations of the 2,3,4M6‐1 topology in 11 and 12.

Single-Molecule Magnets

Molecular Architectures and Building Blocks for Spintronics

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