Syntheses And Properties Of Ln-Co/Ag Heterometallic Complexes

In this thesis, the work is associated with lanthanide-transition heterometallic complexes, and it contains two parts:coordination polymers and molecular magnetic material.Regarding lanthanide-transition heterometallic coordination polymers, using 2,6-pyridinedicarboxylic acid (H2PDA) and 4-hydroxyl-2,6-pyridinedicarboxylic acid (H3CAM) as ligands, a total of thirty-nine heterometallic coordination polymers associated with Lnâ…¢and Coâ…¡or Agâ… metal ions, which are divided into five series, have been synthesized under hydrothermal condition. Lnâ…¢-Coâ…¡-PDA series contain eight isostructrual coordination polymers, and display 3D porous networks with 1D nanosized channels, furthermore, three different types of "water" pipes are found in 1D channels. The study on adsorption properties shows that Ndâ…¢/Gdâ…¢-Coâ…¡-PDA can adsorb radical molecules. Seven Lnâ…¢-Coâ…¡-CAM coordination polymers consist of 2D open frameworks based on double-strand helical motifs, which are further assembled into a 3D porous structure by strong intermolecular hydrogen bonds between hydroxyl groups;at the same time, three Lnâ…¢-Coâ…¡-Cdâ…¡heterotrimetallic coordination polymers have been obtained for the first time. When using Agâ… ion instead of Coâ…¡ion, two series of Ln-Ag coordination polymers based on H2PDA and H3CAM are generated, respectively. Seven Lnâ…¢-Agâ… -PDA and one Ceâ…£-Agâ… -PDA coordination polymers display 2D grid-like, 1D double-chain and wave-like chain structures, respectively, and the luminescence of Dyâ…¢-Agâ… -PDA displays luminescent selectivity for Mg2+ion. The structures of twelve Lnâ…¢-Agâ… -CAM coordination polymers progress from a 3D framework (Laâ…¢-Agâ… -CAM) to honeycomb-like structures (Lnâ…¢-Agâ… -CAM, Ln=Pr-Eu), and to sandwich-like 3D networks (Lnâ…¢-Agâ… -CAM, Ln =Gd-Yb) with the coordination numbers of Lnâ…¢ions decreasing, which are mainly ascribed to the effect of lanthanide contraction, and ferromagnetic coupling is observed between Gdâ…¢ions in Gdâ…¢-Agâ… -CAM.In the aspect of molecular magnetic material, five tetranuclear Lnâ…¢2Coâ…¡2 heterometallic cubanes have been produced by using 2,6-pyridindimethanol (pdmH2) as ligand with the assistant of pivalic acid (pivH) in normal temperature, Dyâ…¢2Coâ…¡2 exhibits slow relaxation of the magnetization and behaves as a single-molecule magnet, which is attributed to the presence of the magnetic anisotropy of Dyâ…¢ion.