Luminescent Er based single molecule magnets with fluorinated alkoxide or aryloxide ligands.

We report the synthesis, structures, and magnetic and luminescence properties of a series of new mono- and dinuclear Er complexes derived from sterically demanding aryloxide and fluorinated alkoxide ligands: [4-Bu-2,6-(PhCH)CHO]Er(THF) (1), [(CF)CO]Er(MeSiOH) (2), [(CF)CO]Er[(MeSi)NH] (3), [(CF)CO]Er(CHCH) (4), [(CF)CO]Er(-MeNCHCH) (5) and {[Ph(CF)CO]Er(μ-OC(CF)Ph)} (6). In compounds 1, 2, and 4, the Er ion is four-coordinated and adopts a distorted trigonal pyramidal geometry, while in 3, 5, and 6, the coordination geometry of Er is impacted by the presence of several relatively short Er⋯F distances, making them rather 6-coordinated. All compounds behave as field-induced Single Molecule Magnets (SMMs) and exhibit an Er characteristic near infrared (NIR) emission associated with the I → I transition with a remarkably long lifetime going up to 73 μs, which makes them multifunctional luminescent SMMs.

Ca(II) and Yb(II) complexes featuring M(C≡C) structural motif: enforced proximity or genuine η -bonding?

Bis(carbazolide) complexes M[3,6-tBu -1,8-(RC≡C) Carb] (THF) (R=SiMe , n=0, M=Ca, Yb; R=Ph, n=1, M=Ca, Yb; n=0, M=Yb) were synthesized through transamination reaction of M[N(SiMe ) ] (THF) with two molar equivalents of carbazoles. The complexes feature M(η -C≡C) structural motif composed of M(II) ions encapsulated by four acetylene fragments due to atypical for alkaline- and rare-earth metals η -interactions with triple C≡C bond. This interaction is evidenced experimentally by X-ray diffraction, Raman spectroscopy in the solid state and by NMR-spectroscopy in the solution.

Using N-Heterocyclic Carbenes as Weak Equatorial Ligands to Design Single-Molecule Magnets: Zero-Field Slow Relaxation in Two Octahedral Dysprosium(III) Complexes.

We report the synthesis, structures, and magnetic investigations of two new octahedral dysprosium complexes, based on the original N-heterocyclic carbene (NHC) tridentate bis(phenoxide) ligand, of the respective formulas -[DyL(THF)Cl] () and -[DyL(THF)][BPh] (), where L = 1,3-bis(3,5-di--butyl-2-oxidophenyl)-5,5-dimethyl-3,4,5,6-tetrahydropyrimidin-1-ium chloride and THF = tetrahydrofuran. The short Dy-O distances in the axial direction in association with the weak donor ability of the NHC moiety provide a suitable environment for slow relaxation of magnetization, overcoming the previous single-molecule magnets based on NHC ligands.

High magnetization reversal barriers in luminescent dysprosium octahedral and pentagonal bipyramidal single-molecule magnets based on fluorinated alkoxide ligands.

We report the synthesis and structures of three luminescent dysprosium(iii) complexes based on fluorinated alkoxide ligands of formulas [Dy(L1)2(THF)4][BPh4]·0.5THF (1), [Dy(L2)2(THF)5][BPh4]·2.5THF (2) and [Dy(L3)2(THF)5][BPh4]·2THF (3) (L1 = (CF3)3CO-, L2 = C6F5C6F4O-, L3 = C6F5C(CH3)O-).

Bis(alkyl) scandium and yttrium complexes coordinated by an amidopyridinate ligand: synthesis, characterization and catalytic performance in isoprene polymerization, hydroelementation and carbon dioxide hydrosilylation.

New neutral bis(alkyl) Sc and Y complexes [N,Npy,N-]Ln(CH2SiMe3)2(THF)n [n = 0, Ln = Sc (1Sc), Y (1Y); n = 1, Ln = Y (1YTHF)] stabilized by a tridentate monoanionic amidopyridinate ligand were straightforwardly prepared by alkane elimination, upon mixing ligand [N,Npy,N-]H and metal precursor Ln(CH2SiMe3)3(THF)2 in toluene at 0 °C. Depending on the work-up conditions, yttrium bis(alkyl)s were isolated as either a pentacoordinate Lewis base free complex [N,Npy,N-]Y(CH2SiMe3)2 (1Y) or as a hexacoordinate THF adduct [N,Npy,N-]Y(CH2SiMe3)2THF (1YTHF). For the smaller Sc ion the only solvent-free complex [N,Npy,N-]Y(CH2SiMe3)2 (1Sc) was isolated as a pentacoordinate species irrespective of the reaction/work-up/crystallization conditions applied.