A salen-type trinuclear Zn2Gd complex.

In the trinuclear title complex, di-µ-acetato-1:2κ(2)O:O';2:3κ(2)O:O'-bis-{µ-6,6'-dimeth-oxy-2,2'-[cyclo-hexane-1,2-diylbis(methanylyl-idene)]diphenolato}-1:2κ(6)O(1),N,N',O(1'):O(6),O(6');2:3κ(6)O(6),O(6'):O(1),N,N',O(1')-2-gadolinium(III)-1,3-dizinc hexa-fluor-idophosphate methanol monosolvate monohydrate, [GdZn2(C22H24N2O4)2(CH3COO)2]PF6·CH3OH·H2O, the two Zn(II) ions are located in the inner N2O2 cavities of two 6,6'-dimeth-oxy-2,2'-[cyclo-hexane-1,2-diylbis(methanylyl-idene)]diphenolate (L) ligands. Both Zn(II) ions are five-coordinated by two O atoms and two N atoms from the L ligand and one O atom of an acetic acid mol-ecule, giving rise to a square-pyramidal geometry around the Zn(II) ions. The Gd(III) ion is nine-coordinated by four O atoms from the outer O2O2 sites of one ligand, and three O atoms from another ligand, in which there is one non-coordinating meth-oxy O atom. Two further O atom from different acetate ligands complete the nine-coordinate environment.

Series of dinuclear and tetranuclear lanthanide clusters encapsulated by salen-type and ß-diketionate ligands: single-molecule magnet and fluorescence properties.

Three dinuclear [Ln2H2OL(1)2(acac)2]·solvent (1, Ln = Gd, solvent = 2CH2Cl2; 2, Ln = Tb, no solvent; 3, Ln = Er, solvent = (C2H5)2O), and two tetranuclear lanthanide clusters [Ln4(µ3-OH)2L(2)2(acac)6]·2(solvent) (4, Ln = Tb, solvent = CH3OH; 5, Ln = Dy, solvent = CH3CN) were characterized in terms of structure, fluorescence and magnetism. The dinuclear lanthanide complexes were constructed by a rigid salen-type ligand H2L(1) = N,N'-bis(salicylidene)-o-phenylenediamine and ß-diketonate (acac = acetylacetonate) ligands, while the tetranuclear clusters were formed from the flexible ligand H2L(2) = N,N'-bis(salicylidene)-1,2-ethanediamine. Crystal structure analysis indicates that the rigid ligand favors the double-decker sandwich structure (Ln2L(1)2), in which the two lanthanide ions have different coordination numbers and geometry, while the more flexible ligand (H2L(2)) leads to planar tetranuclear clusters. The relationship between their respective magnetic anisotropy and ligand-field geometries and their fluorescence properties was investigated. The Dy and Tb-containing clusters exhibit typical visible fluorescence properties, and single-molecule magnet behavior is seen in complex 5.