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An in situ hydrolysis of the P–Cl bonds of the carbophosphazene [{NC(NMe2)}2{NPCl2}] (LPCl2) in the presence of hydrated lanthanide(III) nitrates in a dichloromethane and methanol (2 : 1) solvent mixture afforded a series of novel 1D coordination polymers: [{Ln(LHPO2)3(NO3)2(CH3OH)(H2O)} (Cl)]n {where Ln(III) = Gd (1), Tb (2), Dy (3), or Er (4) and LHPO2 is the hydrolyzed carbophosphazene (LPCl2) ligand}. X-ray crystallographic analysis revealed that complexes 1–4 are isostructural and crystallized in the monoclinic crystal system having P21/c space group. The coordination polymers are formed because of the involvement of the geminal P(O)(OH) moieties of the carbophosphazene ligand. Each lanthanide(III) ion is 9-coordinate (9O) in a distorted muffin geometry. Magnetic measurements revealed that both DyIII and ErIII analogues exhibit field-induced single-molecule magnet (SMM) behavior at 0.8 kOe and 2.2 k Oe, respectively. At such dc fields, the dynamic magnetic susceptibility displays complex behavior with a triple magnetic relaxation contribution for 3, while two contributions were identified for 4. The observed static and dynamic magnetic behavior for complexes 1–4 were further rationalized with the aid of BS-DFT and CASSCF/SO-RASSI/SINGLE_ANISO calculations. [ABSTRACT FROM AUTHOR]

Lanthanide Single‐Molecule Magnets are fascinating objects that break magnetic performance records with observable magnetic bistability at the boiling temperature of liquid nitrogen, paving the way for potential applications in high‐density data storage. The switching of lanthanide SMM has been successfully achieved using several external stimuli such as redox reaction, pH titration, light irradiation or solvation/desolvation thanks to the high sensitivity of the magnetic anisotropy to any structural change in the lanthanide surrounding. Nevertheless, the use of applied high pressure as an external stimulus is largely underused, especially considering that it can be combined with high pressure X‐ray diffraction to establish a complementary structure‐property relationship. This Concept article summarizes the few relevant examples of investigations of lanthanide SMMs under applied high pressure, provides conclusions on the effect of such stimulus on molecular structures and magnetic anisotropy, and finally draws perspective on the future development of magnetic measurements under applied pressure. [ABSTRACT FROM AUTHOR]

The association of lanthanide ions and paracyclophane derivatives has been very scarcely reported in the literature. In this study, elaboration of five coordination lanthanide complexes involving the 1,4(1,4)-dibenzenacyclohexaphane-12,43-diylbis(diphenylphosphine oxide) ligand (L) was achieved with the determination of single-crystal X-ray diffraction structures of four mononuclear complexes of formula [Ln(hfac)3(L)] (hfac- = 1,1,1,5,5,5-hexafluoroacetylacetonate) (Ln = Dy(III) (1-Dy) and Yb(III) (2-Yb)) and [Ln(tta)3(L)] (tta− = 2-tenoyl-trifluoroacetylacetonate) (Ln = Dy(III) (3-Dy) and Yb(III) (4-Yb)) and one dinuclear complex [Na(Dy2(hfac)6(L)2)](BArF) (BArF− = tetrakis[3,5-bis(trifluoromethyl)phenyl]borate) (5-Dy). The compounds were characterized using elemental analysis, IR spectroscopy, DC and AC magnetic measurements and photophysical investigations. L is an efficient organic chromophore for the sensitization of both visible Dy(III) (1-Dy) and near-infrared Yb(III) (2-Yb and 4-Yb) luminescence. The combination of excitation and emission spectra allowed the determination of the crystal field spitting of both the 2F7/2 ground state and 2F5/2 excited state for 2-Yb and 4-Yb. Moreover, 3-Dy and the two Yb(III) derivatives displayed field-induced single-molecule magnet (SMM) behaviour with slow magnetic relaxation occurring through the Raman process only for 2-Yb and 4-Yb, whereas a combination of Orbach and Raman processes was identified for 3-Dy. [ABSTRACT FROM AUTHOR]

Three mixed valence dinuclear Co (III)–Co (II)‐based complexes having general formulae of [CoIICoIII (HL2)2(L1)] [L1H = 2‐hydroxy‐1‐naphthaldehyde (1), o‐vanillin (2), and salicylaldehyde (3)] have been synthesized successfully using Schiff base (LH4) ligand. The complexes were characterized by single‐crystal XRD, powder XRD, IR, and UV–Vis analyses. The CoII ion with elongated octahedral geometry conferred significant magnetic anisotropy with D values being 64.0(8), 71.1(7), and 52.1(3) cm−1 for 1, 2, and 3, respectively. These complexes exhibited single‐molecule magnet behavior with magnetic relaxation occurring mainly through Raman for 1 and 3 whereas direct and Raman for complex 2. The analysis of the static and dynamic magnetic properties was further supported by theoretical calculations using CASSCF/DLPNO‐NEVPT2. [ABSTRACT FROM AUTHOR]

The reaction between the ((E)-N′-(2-hydroxy-3-methoxybenzylidene)pyrazine-2-carbohydrazide) (H2opch) ligand and the metallo-precursor [Dy(hfac)3]·2H2O led to the formation of an homometallic coordination complex with the formula [Dy2(hfac)3(H2O)(Hopch)2][Dy(hfac)4] (1). In presence of both [Dy(hfac)3] 2H2O and the Fe(II) salt, the heterobimetallic tetranuclear [FeDy3(hfac)8(H2O)2(opch)2] (2) was isolated, while the addition of the co-ligand 1,2-Bis(2-hydroxy-3-methoxybenzylidene) hydrazine (H2bmh) led to the formation of two heterobimetallic tetranuclear complexes with the formula [Fe3Dy(hfac)6(opch)2(H2bmh)] C6H14 (3) C6H14 and [Fe2Dy2(hfac)7(opch)2(H2bmh)] 0.5C7H16 (4) 0.5C7H16. Single crystal X-ray diffraction and dc magnetic investigation demonstrated that 3 and 4 involved the iron center in the +II and +III oxidation states. Dynamic magnetic measurements highlighted the single-molecule magnet behavior of 1 and 2 in a zero applied dc field primarily due to the ferromagnetic interactions taking place in these compounds. [ABSTRACT FROM AUTHOR]

Lanthanide Single-Molecule Magnets (SMMs) fascinate the scientific community due to their plethora of potential applications ranging from data storage to spintronic devices and quantum computing. This review article proposes a comprehensive description of the influence of the nuclear spin, i.e. hyperfine interaction, on the magnetic properties of lanthanide SMMs and on quantum information processing of qudit. This influence is analysed for non-Kramers and Kramers lanthanide SMMs as well as for the electronic distribution of the electron in 4f orbitals i.e. oblate and prolate ions. Then the role of magnetic interactions in isotopically enriched polynuclear Dy(III) SMMs is discussed. Finally the possible effect of superhyperfine interaction due to the nuclear spin of elements originating from the surrounding of the lanthanide centre is analyzed. The effect of nuclear spin on the dynamics of the lanthanide SMMs is demonstrated using different techniques such as magnetometry, muon spectroscopy (μ-SR), and Mössbauer and Resonance Vibrational Spectroscopies. [ABSTRACT FROM AUTHOR]

The extreme sensitivity of trivalent lanthanide ions to crystal field variations led to the emergence of single‐molecule magnetic switching under various stimuli. The use of pressure as an external stimulus instead of classic light irradiation, oxidation or any chemical reactions allows a fine tuning of the magnetic modulation. Here the well‐known pure isotopically enriched [162Dy(tta)3(L)]⋅C6H14 (162Dy) Single‐Molecule Magnet (SMM) (tta−=2‐2‐thenoyltrifluoroacetonate and L=4,5‐bis(propylthio)‐tetrathiafulvalene‐2‐(2‐pyridyl)benzimidazole‐methyl‐2‐pyridine) was experimentally investigated by single‐crystal diffraction and squid magnetometry under high applied pressures. Both reversible piezochromic properties and pressure modulation of the slow magnetic relaxation behavior were demonstrated and supported by ab initio calculations. The magnetic study of the diluted sample [162Dy0.05Y0.95(tta)3(L)]⋅C6H14 (162Dy@Y) indicated that variations in the electronic structure have mainly intermolecular origin with weak intramolecular contribution. Quantitative magnetic interpretation concludes to a deterioration of the Orbach process for the benefit of both Raman and QTM mechanisms under applied pressure. [ABSTRACT FROM AUTHOR]

The interest for chiral tris(β‐diketonato)lanthanide complexes in coordination chemistry is huge due to its Lewis acid character, optical activity, and the control of the final compound architecture. The reaction of equimolar quantities of [Dy((−)/(+)hfc)3(H2O)] (hfc− = 3‐(heptafluoropropylhydroxymethylene)‐(+/−)‐camphorate) and L led to the formation of a pair of enantiomers for dinuclear complexes [Dy((−)/(+)hfc)3(L)]2⋅C7H16([(−)/(+)1]⋅C7H16) (L = 4′‐(4′′′‐pyridyl‐N‐oxide)‐1,2′:6′1′′‐bis‐(pyrazolyl)pyridine]). Starting from the previous experimental protocol with the addition of bulky BArF anions, a partial dissociation of the chiral [Dy((−)/(+)hfc)3(H2O)] was observed leading to the isolation of a mono‐dimensional cationic chiral polymer {[Dy((−)/(+)hfc)2(L)][BarF]}n⋅nCH3NO2([(−)/(+)2]n⋅nCH3NO2). Natural circular dichroism (NCD) highlighted an exciton CD couplet for [(−)/(+)2]n but not for (−)/(+)1. The latter behaves as a single‐molecule magnet (SMM) with a blocking temperature up to 4 K, whereas [(−)/(+)2]n is a 1D assembly of field‐induced SMMs with a magnetic relaxation occurring through a Raman process only. [ABSTRACT FROM AUTHOR]

The combination of physical properties sensitive to molecular chirality in a single system allows the observation of fascinating phenomena such as magneto‐chiral dichroism (MChD) and circularly polarized luminescence (CPL) having potential applications for optical data readout and display technology. Homochiral monodimensional coordination polymers of YbIII were designed from a 2,15‐bis‐ethynyl‐hexahelicenic scaffold decorated with two terminal 4‐pyridyl units. Thanks to the coordination of the chiral organic chromophore to Yb(hfac)3 units (hfac−=1,1,1,5,5,5‐hexafluoroacetylaconate), efficient NIR‐CPL activity is observed. Moreover, the specific crystal field around the YbIII induces a strong magnetic anisotropy which leads to a single‐molecule magnet (SMM) behaviour and a remarkable room temperature MChD. The MChD‐structural correlation is supported by computational investigations. [ABSTRACT FROM AUTHOR]

The reaction between the 2-(1-(2,6-di(pyrazol-1-yl)-4-methylpyridyl)-4,5-(4,5-bis(propylthio)-tetrathiafulvalenyl)-1H-benzimidazol-2-yl)-pyridine ligand (L), 1 equivalent of Ln(hfac)3·2H2O/Dy(tta)3·2H2O (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonate, tta− = 2-thenoyltrifluoroacetonate) and M(hfac)2·2H2O leads to the formation of heteroleptic 3d–4f dinuclear complexes of formula [MLn(hfac)5(L)]n (M(II) = Cd, Zn, Co, Mn, Ni and Ln(III) = Dy, Yb, Nd) and [ZnDy(tta)2(hfac)3(L)]·(CH2Cl2). Their X-ray structures reveal that the two coordination sites are occupied by one Ln(III) ion and one M(II) transition metal respectively. The M(II) ions are coordinated to the benzoimidazolylpyridine (bzip) moiety in a N2O4 coordination sphere, while the Ln(III) ions are coordinated to the 2,6-di(pyrazol-1-yl)-4-pyridine (dpp) moiety in a N3O6 surrounding. When Dy(III) ion is used a field-induced Single-Molecule Magnet (SMM) behavior is detected with a magnetic relaxation time slightly dependent to the nature of the vicinal divalent transition metal. On the other hand, when the Yb(III) is used, intense, moderated or quenched 2F5/2 → 2F7/2 NIR luminescence is observed when the Yb(III) ion is respectively associated with the Zn(II), Mn(II) and Ni(II)/Co(II) ion. The emission intensity can be modulated in function of the metal-to-ligand charge transfer and d–d transition intensities. The replacement of the divalent transition metal by a trivalent lanthanide leads to the formation of heteroleptic 4f–4f′ dinuclear complexes of formula [Ln2−xLn′x(hfac)6(L)]·a(CH2Cl2)·b(C6H14) and [Dy1.11Nd0.89(tta)3(hfac)3(L)]. The coordination selectivity is based on the radius. Among the 4f–4f′ series, the Dy(III) derivatives displayed such ion in N2O6 eight-coordinated sphere allowing the observation of SMM behavior. The three compounds [Dy1.21Nd0.79(hfac)6(L)]·2(CH2Cl2)·(C6H14), [Yb1.04Nd0.96(hfac)6(L)] and [YbPr(hfac)6(L)] displayed respectively Nd(III), modarated Yb(III) and intense Yb(III) NIR emissions. [ABSTRACT FROM AUTHOR]

Three new heterobimetallic Schiff base complexes of formula [(LZnCl)2Gd(H2O)](ZnCl4)0.5 (2), [(LZn(OH))(LZnCl)Sm(H2O)](ZnCl4)0.5 (3) and [(LZnCl0.5(OH)0.5)(LZnCl)Dy(H2O)](ZnCl4)0.5 (4) were designed from the reaction of the metallo‐ligand ZnL (1) (H2L=N, N′‐bis(3‐methoxysalicylaldiimine)‐1,3‐propylene‐2‐ol) and lanthanide salt in a ratio 1 to 1. The crystallographic structures of 2–4 were resolved by single crystal X‐ray diffraction. Light irradiation allowed the observation of a broad emission centered on the organic ligand which is exalted upon Zn(II) coordination. 1 is able to act as a metallo‐organic chromophore for the sensitization of the Sm(III) luminescence. Finally the Dy(III) derivative displayed Single‐Molecule Magnet (SMM) behavior with an opening of the hysteresis loop up to 5 K and a magnetic relaxation operating through Orbach, Raman and Quantum Tunneling of the Magnetization (QTM) at 0 Oe while under an applied magnetic field the QTM is efficiently cancelled. [ABSTRACT FROM AUTHOR]

The effects of isotopic enrichment and magnetic dilution have been investigated in a heterobimetallic complex of formula [Zn2L2ADyCl3]·2H2O (ADyZn2) (A = 162 and 163) presenting slow relaxation of the magnetization. Isotopic substitution for 162Dy (I = 0) and 163Dy (I = 5/2) leads to a shift in the relaxation times depending on the suppression or enhancement of the hyperfine interactions. The release of the dipolar interactions through magnetic dilution in a Y(III)-based matrix enhances the slow relaxation of the magnetization and the visibility of the nuclear spin effect. A comparison of the hysteresis loop at 0.5 K for bulk and diluted analogues of pure isotopically enriched complexes suggested a role of the nuclear spin in the interaction between the active system and the matrix. [ABSTRACT FROM AUTHOR]

Single‐Molecule Magnet (SMM) property is by essence molecular, while commonly measured in solid crystalline state. Solvent crystallization molecules are usually neglected in the analysis and interpretation of solid‐state properties. The solvation/desolvation process in the polyoxometalate(POM)‐based Na9[Er(W5O18)2] ⋅ 35 H2O SMM demonstrates that the dehydrated form relaxes more than 1000 times faster than the initial state, while the rehydration process allows the quasi complete recovering of the initial magnetic behaviour. This dehydration process is monitored by thermogravimetric analysis (TGA) and temperature‐dependent X‐ray powder diffraction, and rationalized by periodic quantum chemical calculations evidencing the tremendous role of the labile water molecules in the stability of the edifice. Ab‐initio calculations highlight that sodium ions localization in the structure drive the magnetic responses. Isotopic enrichment with nuclear spin free (166Er, I=0) ErIII ions shows that the relaxation dynamics in the quantum regime depends on the nuclear spin. [ABSTRACT FROM AUTHOR]

Two new TTF‐based ligands involving terpyridine moiety (L1=4‐(4′‐Methyl‐phenyl‐2,2 : 6',2"‐terpyridine −4‐ylmethylthio)‐5‐(2‐cyanoethylthio)‐4′,5′‐bis(methylthio)tetrathiafulvene and L2=4‐(4′‐Methyl‐phenyl‐2,2 : 6',2"‐terpyridine −4‐ylmethylthio)‐5‐(2‐cyanoethylthio)‐4′,5′‐bis(propylthio)tetrathiafulvene) have been synthesized and seven related mononuclear complexes were isolated as single crystals. The 2 : 1 (ligand : metal) complexes of formula [Co(L1)2](NO3)2 (2) and [Co(L1)2](BF4)2 (3) displayed thermal spin crossover transition while the 1 : 1 complexes of formula [CoCl2(L1)](DMF)2 (4), [CoBr2(L1)] ⋅ (DMF) (5), [CoCl2(L2)] ⋅ (DMF) ⋅ 0.5(Et2O) (6) and [CoBr2(L2)] ⋅ (DMF) (7) displayed slow magnetic relaxation through either Raman or Raman/Direct combination processes. A relationship between the structure and the nature of the magnetic relaxation processes is proposed. [ABSTRACT FROM AUTHOR]

A field‐induced chiral YbIII Single‐Molecule Magnet (SMM) displayed an unprecedented near‐infrared circularly polarized luminescence (NIR‐CPL) in the solid‐state. The bridging bis(1,10‐phenantro[5,6b])tetrathiafulvalene triad (L) allowed an efficient sensitization of the NIR 2F5/2→2F7/2 emission while the NIR‐CPL is associated to the f‐f transitions of the YbIII ion bearing chiral β‐diketonate derived‐camphorate ancillary ligands. [ABSTRACT FROM AUTHOR]

Divalent lanthanide organometallics are well‐known highly reducing compounds usually used for single electron transfer reactivity and small molecule activation. Thus, their very reactive nature prevented for many years the study of their physical properties, such as magnetic studies on a reliable basis. Herein, the access to rare organometallic sandwich compounds of TmII with the cyclooctatetraenyl (Cot) ligand impacts on the use of divalent organolanthanide compounds as an additional strategy for the design of performing Single Molecule Magnets (SMM). The first divalent thulium sandwich complex with f13 configuration behaving as a single‐molecule magnet in absence of DC field is highlighted. [ABSTRACT FROM AUTHOR]

The coordination reaction of the [Dy(hfac)3(H2O)2] units (hfac-= 1,1,1,5,5,5- hexafluoroacetylacetonate) with the two quinone-based derivatives 4,7-di-tert-butyl-2-(3,5-di-tert-butyl-4- oxocyclohexa-2,5-dien-1-ylidene)benzo[d][1,3]dithiole-5,6-dione (L¹) and 7,8-dithiabicyclo[4.2.0]octa-1,5- diene-3,4-dione,2,5bis(1,1-dimethylethyl) (L²) led respectively to the complexes [Dy(hfac)3(H2O)(L¹)] (1) and [Dy(hfac)3(H2O) (L²)]•(C6H14)(CH2Cl2) (2)•(C6H14)(CH2Cl2). X-ray structures on single crystal of 1 and 2•(C6H14)(CH2Cl2) revealed the coordination of the DyIII on the bischelating oxygenated quinone site and the formation of dimeric species through hydrogen bonds. Ac magnetic measurements highlighted field-induced single-molecule magnet behavior with magnetic relaxation through a Raman process. [ABSTRACT FROM AUTHOR]

The complexes [Dy2(tta)6(H2SQ)] (Dy-H2SQ) and [Dy2(tta)6(Q)]-2CH2Cl2 (Dy-Q) (tta = 2-thenoyltrifluoroacetonate) were obtained from the coordination reaction of the Dy(tta)32H2O units with the 2,20-benzene-1,4-diylbis(6-hydroxy-4,7-di-tert-butyl-1,3-benzodithiol-2-ylium-5-olate ligand (H2SQ) and its oxidized form 2,20-cyclohexa-2,5-diene-1,4-diylidenebis(4,7-di-tert-butyl-1,3- benzodithiole-5,6-dione (Q). The chemical oxidation of H2SQ in Q induced an increase in the coordination number from 7 to 8 around the DyIII ions and by consequence a modulation of the field-induced Single-Molecule Magnet behavior. Computational results rationalized the magnetic properties of each of the dinuclear complexes. [ABSTRACT FROM AUTHOR]

An alternative strategy for the synthesis of terpyridine based switchable molecular tweezers has been developed to incorporate anisotropic Mn(III)–salphen complexes. The free ligand was synthesized using a building block strategy based on Sonogashira coupling reactions and was then selectively metalated with manganese in a last step. The conformation of the tweezers was switched from an open 'W' shaped form to a closed 'U' form by Zn(II) coordination to the terpyridine unit bringing the two Mn–salphen moieties in close spatial proximity as confirmed by X-ray crystallography. An alternate switching mechanism was observed by the intercalation of a bridging cyanide ligand between the two Mn–salphen moieties that resulted in the closing of the tweezers. These dual stimuli are attractive for achieving multiple controls of the mechanical motion of the tweezers. A crystallographic structure of unexpected partially oxidized closed tweezers was also obtained. One of the two Mn–salphen moieties underwent a ligand-centered oxidation of an imino to an amido group allowing an intramolecular Mn–Oamide–Mn linkage. The magnetic properties of the manganese(III) dimers were investigated to evaluate the magnetic exchange interaction and analyze the single molecule magnet behavior. [ABSTRACT FROM AUTHOR]

The two mononuclear complexes of the formula [Dy(tta)3(L)] (1) and [Dy(hfac)3(L)] (2) (where tta- = 2-thenoytrifluoroacetylacetonate and hfac- = 1,1,1,5,5,5-hexafluoroacetylacetonate) were obtained from the coordination reaction of the Dy(tta)3.2H2O or Dy(hfac)3.2H2O units with the 1,10-phenantroline-5,6-dione ligand (L). Their structures have been determined by X-ray diffraction studies on single crystals, and they revealed a supramolecular assembly of tetramers through σ-π interactions. Both complexes displayed a Single-Molecule Magnet (SMM) behavior without an external applied magnetic field. Magnetic relaxation happened through Orbach, Raman and Quantum Tunneling of the Magnetization (QTM). Wavefunction theory calculations were realized to rationalize the magnetic properties. [ABSTRACT FROM AUTHOR]

The complexes [Ln2(hfac)6(L)]•nC6H14 (Ln = Dy (1) n = 0, Yb (2) n = 1) with the L chiral 3,14-di-(2-pyridyl)-4,13-diaza[6]helicene ligand (hfac- = 1,1,1,5,5,5-hexafluoroacetylacetonate) have been synthesized in their racemic form and structurally and magnetically characterized. Both complexes behave as field-induced single molecule magnets in the crystalline phase. These magnetic properties were rationalized by ab initio calculations. [ABSTRACT FROM AUTHOR]

Muon spin relaxation (μSR) experiments on a single-molecule magnet enriched in different Dy isotopes detect unambiguously the slowing down of the zero field spin dynamics for the non-magnetic isotope. This occurs in the low temperature regime dominated by quantum tunnelling, in agreement with previous ac susceptibility investigations. In contrast to the latter, however, μSR is sensitive to all fluctuation modes affecting the lifetime of the spin levels. [ABSTRACT FROM AUTHOR]

Single‐molecule magnet (SMM) behavior of dysprosium‐based dimers was optimized by substitution of a DyIII ancillary ligand (hfac– in the previously reported DyPyNO and tta– in Dy). A clear hysteresis opening is visible at 0.5 K for Dy that allows for the determination of an antiferromagnetic (AF) coupling of –2.92 cm–1 (S = 1/2, gz = 19.58) which was confirmed by ab initio calculations. Comparison with the results of DyPyNO shows that stronger AF coupling correlates with better SMM behavior. This is further demonstrated by diamagnetic substitution, and a Y–Dy species (YDy) highlights that the strong AF magnetic interaction in Dy significantly enhances magnetic relaxation at low temperature. This coupling is also expected to be at the origin of the unexpectedly weak isotopic effect observed for the isotopically pure parents of Dy, namely 161Dy and 164Dy. [ABSTRACT FROM AUTHOR]

Since the 1990s and the discovery of the first Single Molecule Magnets (SMMs), chemists and physicists have been working in concert to elaborate such molecular systems and understand their peculiar properties. Especially the use of lanthanide ions in the design of SMMs exploded with the discovery of the first example of mononuclear Tb III -based complex which displayed a slow magnetic relaxation in 2003. This high-degree of interest comes from the diverse potential applications in quantum computing, high-density data storage devices and spintronics. Recently, the specific luminescence properties of the lanthanide ions were correlated to the magnetic ones. Even if the most common lanthanide ions used in the elaboration of SMMs are the Dy III , Tb III and Er III ions, new SMMs involving others lanthanide ions (Yb III , Ce III , Nd III , Ho III and Tm III ) started to emerge. This review presents the research endeavour in the area of these uncommon lanthanide-based SMMs and underlines the different approaches to better understand their physical properties. [ABSTRACT FROM AUTHOR]

The reaction between the TTF-fused dipyrido[3,2-a:2',3'-c]phenazine (dppz) ligand (L) and 1 equiv of Ln(hfac)3·2H2O (hfac- = 1,1,1,5,5,5-hexafluoroacetyacetonate) or 1 equiv of Ln(tta)3·2H2O (tta- = 2-thenoyltrifluoroacetonate) (LnIII = DyIII or YbIII) metallic precursors leads to four mononuclear complexes of formula [Ln(hfac)3(L)]·C6H14 (LnIII = DyIII (1), YbIII (2)) and [Ln(tta)3(L)]·C6H14 (LnIII = DyIII (3), YbIII (4)), respectively. Their X-ray structures reveal that the LnIII ion is coordinated to the bischelating nitrogenated coordination site and adopts a D4d coordination environment. The dynamic magnetic measurements show a slow relaxation of the DyIII magnetization for 1 and 3 with parameters highlighting a slower relaxation for 3 than for 1 (t0 = 4.14(±1.36) × 10-6 and 1.32(±0.07) × 10-6 s with Δ = 39(±3) and 63.7(±0.7) K). This behavior as well as the orientation of the associated magnetic anisotropy axes have been rationalized on the basis of both crystal field splitting parameters and ab initio SA-CASSCF/RASSI-SO calculations. Irradiation of the lowest-energy HOMO → LUMO ILCT absorption band induces a ²F5/2 → ²F7/2 Yb-centered emission for 2 and 4. For these YbIII compounds, Stevens operators method has been used to fit the thermal variation of the magnetic susceptibilities, and the resulting MJ splittings have been correlated with the emission lines. [ABSTRACT FROM AUTHOR]

The influence of nuclear spin on the magnetic hysteresis of a single-molecule is evidenced. Isotopically enriched DyIII complexes are synthesized and an isotopic dependence of their magnetic relaxation is observed. This approach is coupled with tuning of the molecular environment through dilution in an amorphous or an isomorphous diamagnetic matrix. The combination of these approaches leads to a dramatic enhancement of the magnetic memory of the molecule. This general recipe can be efficient for rational optimization of single-molecule magnets (SMMs), and provides an important step for their integration into moleculebased devices. [ABSTRACT FROM AUTHOR]

The association of the two 4,5-bis(thiomethyl)-4′-carboxytetrathiafulvalene (H L1) and 4,5-bis(thiomethyl)-4′-(2-pyridyl- N-oxide)carbamoyltetrathiafulvalene ( L2) with the metalloprecursor [Dy(tta)3] ·2H2O (tta = 2-thenoyltrifluoroacetonate) leads to the formation of the dinuclear complex of formula [Dy(tta)2( L1)( L2)]2 ·2CH2Cl2. Static magnetic measurements highlight significant ferromagnetic interactions between the DyIII ions, and dynamic magnetic measurements demonstrate single-molecule-magnet behaviour with an energy barrier of 20 cm-1 and a relaxation time of 8.6(9) × 10-6 s. The thermal dependence of the magnetic susceptibility was evaluated by using a crystal field approach (Stevens operators), which confirmed the Ising character of the system. Finally, electrochemistry shows a complex multiredox system with the successive oxidations of the two tetrathiafulvalene (TTF) ligands. [ABSTRACT FROM AUTHOR]

The reactions between the bis(1,10-phenantro[5,6-b])tetrathiafulvalene triad (L) and the metallo-precursors Yb(hfac)3(H2O)2 (hfac− = 1,1,1,5,5,5-hexafluoroacetylacetonato anion) and Dy(facam)3 (facam− = 3-trifluoro-acetyl-(+)-camphorato anion) lead to the formation of two dinuclear complexes of formula [Yb2(hfac)6(L)]·2(C7H16) ((1)·2(C7H16)) and [Dy2((+)facam)6(L)]·2(C6H14) ((2)·2(C6H14)). The X-ray structures reveal that the L triad bridges two terminal Yb(hfac)3 or Dy(facam)3 units. (1)·2(C7H16) behaved as a near infrared YbIII centered emitter and a field-induced Single-Molecule Magnet (SMM) while (2)·2(C6H14) displayed SMM behavior in both zero- and in-dc field. The magnetization mainly relaxes through a Raman process for both complexes under an optimal applied magnetic field. [ABSTRACT FROM AUTHOR]

A redox active dinuclear complex [Yb(tta)2(L1)(L2)]2·1.4(CH2Cl2) displays single molecule magnet behaviour with MJ = ±7/2 ground state. The anisotropic barrier Δ is evaluated by the three dc data fit, ac analysis and emission spectrum demonstrating the correlation between magnetic and optical properties. [ABSTRACT FROM AUTHOR]

Front Cover: Decorated Tetrathiafulvalene-Based Ligands: Powerful Chemical Tools for the Design of Single-Molecule Magnets (Eur. J. Inorg. B The Front Cover b shows a single-molecule magnet library involving tetrathiafulvalene-based ligands. B The Front Cover b shows a single-molecule magnet library involving tetrathiafulvalene-based ligands. [Extracted from the article]

A correction to the article "A Luminescent and Sublimable DyIII Based Single-Molecule Magnet"that was published in a 2012 issue is presented.

The [Dy(tta)3(L)] complex behaves as a single ion magnet both in its crystalline phase and in solution. Experimental and theoretical magnetic anisotropy axes perfectly match and lie along the most electro-negative atoms of the coordination sphere. Both VSM and MCD measurements highlight the robustness of the complex, with persistence of the memory effect even in solution up to 4 K. [ABSTRACT FROM AUTHOR]