title: Lanthanide metalloligand strategy toward d-f heterometallic metal-organic frameworks: magnetism and symmetric-dependent luminescent properties.
abstract: On the basis of lanthanide metalloligands, [Ln(ODA)3](3-) (H2ODA = oxydiacetic acid), three series of d-f heterometallic metal-organic frameworks, {[Co(H2O)6]·[Ln2(ODA)6Co2]·6H2O}n [1; Ln = Gd (1a), Dy (1b), and Er (1c)], {[Ln2(ODA)6Cd3(H2O)6]·mH2O}n [2; Ln = Pr (2a), Nd (2b), Sm (2c), Eu (2d), and Dy (2e), m = 9, 6, or 3], and {[Cd(H2O)6]·[Ln2(ODA)6Cd2]·mH2O}n [3; Ln = Dy (3a), Ho (3b), Er (3c), Tm (3d), and Lu (3e), m = 6 or 12], were designed and synthesized by a solvent volatilization and hydrothermal method. Magnetic investigation of 1 reveals the ferromagnetic interactions between the metal ions. In 2, Ln(III) ions occupied the inversion centers, which are confirmed by the fact that the emission intensity ratio of (5)D0 → (7)F1 to (5)D0 → (7)F2 of the Eu(III) ion is much more than 3 in 2d. It is worth noting that, in 2d, the intensity ratio I((5)D0→(7)F1)/I((5)D0→(7)F2) could decrease significantly upon the introduction of different hydrophilic guest molecules, which implies that the luminescent properties of 2d have a strong dependence on the geometry of the first coordination sphere of the Eu(III) ion.
authors.affiliation: Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, Lanzhou University , Lanzhou 730000, P. R. China.
authors.forename: Xiao-feng
authors.initials: XF
authors.lastname: Huang
authors.forename: Jing-xin
authors.initials: JX
authors.lastname: Ma
authors.forename: Wei-sheng
authors.initials: WS
authors.lastname: Liu