New π-Carbazolyl Dy(III) Half-Sandwich Complex Showing a Single-Molecule-Magnet Behavior

International audienceWe report the synthesis, structure and magnetic investigations of a new Dy 3+ heteroleptic complex [Dy(tBu 4 Carb)(o-Me 2 N-C 6 H 4 CH 2) 2 ]•C 7 H 8 (1) (tBu 4 Carb = 1,3,6,8-Tetra-tert-butyl-9H-carbazole, o-Me 2 N-C 6 H 4 CH 2) 2 = oN ,N-dimethylaminobenzyl). The carbazolyl ligand exhibits an unprecedented 5 -interaction with the magnetically anisotropic dysprosium(III) ion resulting in a genuine zero-field singlemolecule magnet behavior

Single-molecule magnet behaviour in a Dy( iii ) pentagonal bipyramidal complex with a quasi-linear Cl–Dy–Cl sequence

International audienceWe report the synthesis and magnetic investigation of a dysprosium pentagonal bipyramidal complex [Dy(THF)5Cl2][BPh4] (1) exhibiting a linear Cl–Dy–Cl sequence suitable for providing a coordination environment allowing a zero-field slow relaxation of the magnetization. Besides, the complex also shows dual luminescence originating from [BPh4]− and Dy3+

Amido Analogues of Nonbent Lanthanide (II) and Calcium Metallocenes. Heterolytic Cleavage of π-Bond Ln–Carbazolyl Ligand Promoted by Lewis Base Coordination

International audienc

Synthesis, structure, magnetic and luminescence properties of two dysprosium single-molecule magnets based on phenoxide dye ligands

International audienceWe report here two dysprosium complexes based on phenoxidebased emissive ligands 1-(2,4-dimetylphenylazo)-2-naphtholate (L1) and anthracenolate (L2). While 1 is a dinuclear homoleptic complex [Dy 2 (L1) 6 ]•2C 7 H 8 exhibiting a zero-field slow relaxation of the magnetization, 2 is a mononuclear complex [Dy(L2) 3 (py) 3 ] (py = pyridine) showing a field-induced relaxation

Single-molecule magnet behavior in luminescent carbazolyl Dy( iii ) octahedral complexes with a quasi linear N − –Dy–N − angle

International audienc

Thermally Stable Ln(II) and Ca(II) Bis(benzhydryl) Complexes: Excellent Precatalysts for Intermolecular Hydrophosphination of C-C Multiple Bonds

International audienceA series of Ln(II) and Ca(II) bis(alkyl) complexes with bulky benzhydryl ligands, [(p-tBu-C6H4)(2)-CH](2)M(L-n) (M = Sm, L = DME, n = 2 (1); M = Sm, Yb, Ca, L = TMEDA, n = 1 (2, 3, 4), were synthesized by the salt-metathesis reaction of MI2(THF)(n) (n = 0-2) and [(p-tBu-C6H4)(2)CH]Na--(+). In complex 1, the benzhydryl ligands are bound to the metal center in eta(2)-coordination mode. Unlike complex 1, in isomorphous complexes 3 and 4, due to the coordination unsaturation of the metal center, the both benzhydryl ligands coordinate to the metal in eta(3)-fashion. In complex 2, one ligand is eta(3)-coordinated while the second one is eta(4)-coordinated to the Sm(II) ion. Complexes 2-4 demonstrated unprecedented thermal stability: no evidence of decomposition was observed after heating their solutions in C6D6 at 100 degrees C during 72 h. Complex 1 behaves differently: thermolysis in C6D6 solution at 75 degrees C results in total decomposition in 8 h. Addition of DME promotes decomposition of 2-4 and makes it feasible at 40 degrees C. Complexes 1-4 demonstrated high catalytic activity and excellent regio- and chemoselectivities in intermolecular hydrophosphination of double and triple C-C bonds with both primary and secondary phosphines. Complexes 2 and 3 enable addition of PhPH2 toward the internal C=C bond of Z- and E-stilbenes with 100% conversion under mild conditions. Double sequential hydrophosphination of phenylacetylene with Ph2PH and PhPH2 was realized due to the application of Yb(II) complex as a catalyst

Divalent Heteroleptic Ytterbium Complexes – Effective Catalysts for Intermolecular Styrene Hydrophosphination and Hydroamination

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Base-Free Lanthanoidocenes(II) Coordinated by Bulky Pentabenzylcyclopentadienyl Ligands

Metalation of Cp^Bn5H with PhCH₂K (1:1 molar ratio) and subsequent reactions with 0.5 equiv of LnI₂(THF)_<i>n</i> (Ln = Yb, Sm, Eu, <i>n</i> = 2, 3) (THF, 30 °C, 1 h) afforded new lanthanoidocenes (Cp^Bn5)₂Ln (Ln = Yb (<b>1</b>), Sm (<b>2</b>), Eu (<b>3</b>)), which were isolated in reasonable yields. The X-ray diffraction studies revealed that the obtained complexes adopt the structures of bent sandwiches (Cp_Centr–Ln–Cp_Centr = 141.8–142.9°). Complexes <b>1</b>–<b>3</b> do not contain coordinated Lewis base molecules directly after recrystallization from toluene at ambient temperature; however they feature short contacts between Ln­(II) ions and <i>o</i>-carbon atoms of two pendant Ph groups. The reaction of equimolar amounts of YbI₂(THF)₂ and Cp^Bn5K in DME afforded monocyclopentadienyl Yb­(II) complex [Cp^Bn5Yb­(DME)­(μ-I)]₂ (<b>4</b>). Complex <b>4</b> proved to be a centrosymmetric iodo-bridged dimer with trans-disposed cyclopentadienyl ligands, and no interactions of the Yb­(II) ion with pendant Ph groups were detected. Complexes <b>1</b>–<b>3</b> were inert toward Lewis bases (THF, DME, PMe₃, TMEDA), small molecules (H₂, SiH₄, N₂, CO), and molecules containing multiple C–C bonds (CH₂CH₂, PhCHCH₂, trans-PhCHCHPh, cis-PhCHCHPh, CH₂CH–CHCH₂, Ph–CHCH–CHCH–Ph, PhCCPh, Me₃SiCCSiMe₃). Among compounds <b>1</b>–<b>3</b> only the samarium derivative <b>1</b> reacts with bipy and phenazine, affording Sm^III complexes Cp^Bn5₂Sm­(bipy^–•) (<b>5</b>) and [(Cp^Bn5)₂Sm]₂[μ-η³:η³-(C₁₂H₈N₂)^2–] (<b>6</b>). Complex <b>4</b> when illuminated with natural light undergoes redox reaction and in 72 h transforms into the mixed-valent compound {[Cp^Bn5Yb^IIII₂(μ-OMe)]₂}₂­{Yb^II(DME)₃} (<b>7</b>), being a separated ion pair

Base-Free Lanthanoidocenes(II) Coordinated by Bulky Pentabenzylcyclopentadienyl Ligands

Metalation of Cp^Bn5H with PhCH₂K (1:1 molar ratio) and subsequent reactions with 0.5 equiv of LnI₂(THF)_<i>n</i> (Ln = Yb, Sm, Eu, <i>n</i> = 2, 3) (THF, 30 °C, 1 h) afforded new lanthanoidocenes (Cp^Bn5)₂Ln (Ln = Yb (<b>1</b>), Sm (<b>2</b>), Eu (<b>3</b>)), which were isolated in reasonable yields. The X-ray diffraction studies revealed that the obtained complexes adopt the structures of bent sandwiches (Cp_Centr–Ln–Cp_Centr = 141.8–142.9°). Complexes <b>1</b>–<b>3</b> do not contain coordinated Lewis base molecules directly after recrystallization from toluene at ambient temperature; however they feature short contacts between Ln­(II) ions and <i>o</i>-carbon atoms of two pendant Ph groups. The reaction of equimolar amounts of YbI₂(THF)₂ and Cp^Bn5K in DME afforded monocyclopentadienyl Yb­(II) complex [Cp^Bn5Yb­(DME)­(μ-I)]₂ (<b>4</b>). Complex <b>4</b> proved to be a centrosymmetric iodo-bridged dimer with trans-disposed cyclopentadienyl ligands, and no interactions of the Yb­(II) ion with pendant Ph groups were detected. Complexes <b>1</b>–<b>3</b> were inert toward Lewis bases (THF, DME, PMe₃, TMEDA), small molecules (H₂, SiH₄, N₂, CO), and molecules containing multiple C–C bonds (CH₂CH₂, PhCHCH₂, trans-PhCHCHPh, cis-PhCHCHPh, CH₂CH–CHCH₂, Ph–CHCH–CHCH–Ph, PhCCPh, Me₃SiCCSiMe₃). Among compounds <b>1</b>–<b>3</b> only the samarium derivative <b>1</b> reacts with bipy and phenazine, affording Sm^III complexes Cp^Bn5₂Sm­(bipy^–•) (<b>5</b>) and [(Cp^Bn5)₂Sm]₂[μ-η³:η³-(C₁₂H₈N₂)^2–] (<b>6</b>). Complex <b>4</b> when illuminated with natural light undergoes redox reaction and in 72 h transforms into the mixed-valent compound {[Cp^Bn5Yb^IIII₂(μ-OMe)]₂}₂­{Yb^II(DME)₃} (<b>7</b>), being a separated ion pair