Synthesis, Crystal Structures And Properties Of Transition And Lanthanide Metal Complexes Constructed By (Iso) Nicotinic Acid

Metal-Organic Frameworks (MOFs)- a new class of porous material is attracting attention due to demonstrations of their large pore sizes, high apparent surface areas, selective uptake of small molecules, andoptical or magnetic responses to the inclusion of guests. More importantly, their synthesis from molecular building blocks holds the potential for directed tailoring of these properties.In this thesis, eleven novel transition and lanthanide metal complexes, which were ligated with isonicotinic acid and nicotinic acid, have been synthesized, and all of them were studied by Elemental Analysis (EA), IR, thermogravimetric analysis (TGA) . We also do our best to test their magnetism and fluorescence.1.Under hydrothermal conditions, three transition metal complexes [Zn₃Cu₂(IN)₈](HIN=isonicotinicacid)(1), [Co(C₆H₄NO₂)₂]n(2), [CuCl (C₆H₅NO₂)]n (3) have been synthesized. Complex (1) is the first mixed metal Zn/Cu coordination polymer with a novel three dimensional structure which consists of an unusual helical [–Zn(Cu)-IN–]n chains along the b axis. The very strong blue fluorescence for (1) can be observed in the solid state. Complex (2) contains chiral two dimensional layers assembled from Co²⁺ cations and nicotinate anions.The Co2+ cations lie on two fold rotation axes and are coordinated by two N atoms and two carboxylate groups. Each nicotinate anion links two Co2+ cations. Complex (3) exhibits polymeric chains extended in the b-axis direction .The Cu atom is tetrahedrally coordinated by three Cl atoms and the N atom of isonicotinic acid. The Cu and Cl atoms lie on mirror planes, Each Cu2Cl2 ring is centrosymmetric. The carboxyl groups are connected by O-H…O hydrogen bonds into an infinite chain running in the [1,0,1] direction.2. Under hydrothermal conditions, a lanthanide metal complex [Nd(CO₃)(OH)]_n(4), has a three-dimensional framework structure assembled from NdO10 polyhedra and CO₃^2- groups. The Nd atom is coordinated by eight O atoms from CO₃^2- groups and two OH anions, while the C atom is coordinated by three O atoms. Nd, two O and C atoms are located on a mirror planes.3.Under hydrothermal conditions, four novel complexs Zn_1.5Dy₂₆(IN)₂₅(CH₃COO)₈(CO₃)₁₁(OH)₂₆(H₂O)₂₆(5),Dy₃₀(IN)₁₆(CH₃COO)₁₄(CO₃)₁₅(OH)₃₀(H₂O)₃₆(6), Dy₂₆(IN)₂₃(CH₃COO)₉(CO₃)₁₀(OH)₂₆(H₂O)₃₁ (7), Dy₂₆(NIC)₂₄(CH₃COO)₈(CO₃)₁₁(OH)₂₆(H₂O)₁₈ClCu₃(8) with the same biggest nanosized spherical hydroxo Dy₂₆ clusters(Dy₂₆@CO₃) have been synthesized. Complex (5) is a novel 3D coordination polymer based on linkages of the Dy₂₆ clusters and zinc centers by organic ligands. Two crystallographically independent zinc metal centers (Zn1 and Zn2) connect Dy₂₆ clusters to form a 2D coordination layer along crystallographic [1, 1, 1] direction. Adjacent layers are connected to each other by using other chains [-Dy₂₆-IN]n to generate the 3D framework of (5) along the c axis. Complex (6) is a discrete molecule. The structure of (6) consists of the same Dy₂₆@CO₃ core and a small Dy4 cluster. One IN ligand acts as a bridge to connect Dy₂₆ and Dy₄ clusters. The structure building units are connected by O-H…O ,N-H…O hydrogen bonds into a 3D framwork. The structure building units of complex (7) is only an isolated Dy₂₆@CO₃ cluster. It is a nanosized cluster. The structure building units are connected by O-H…O hydrogen bonds into a 3D framwork. Complex (8) consists of the same Dy₂₆@CO₃ core, use nicotinic acid as the ligand to link the Dy₂₆ clusters and copper centers to form a 3D coordination polymer. If we use abstract methods to regard one Dy₂₆@CO₃ clusters as a point, the 3D framwork of complex (8) is a traditional perovskite-like topological along the a axis.4.Under hydrothermal conditions, three 3d-4f complexes LnCu(NIC)₄·H₂O [Ln=Nd(9),Eu(10),La(11);HNIC=nicotinic acid] have been synthesized. Complexs(9)-(11) are the iso-structural complex, and all of them are 3D coordination polymers based on the linkages of the Ln (â…¢)and Cu(â… ) centers by NIC ligands. Ln centers are nine coordinated by O atoms of NIC ligands and Cu centers are four coordinated by N atoms of NIC ligands. Adjacent Cu centers and Ln centers are bonded by nine NIC ligands to make a four metals ring.