Structures And Properties Of Some Polynuclear Complexes And Coordination Polymers

In the field of coordination chemistry, polynuclear molecules and coordination polymers currently attract considerable interest. In this thesis, 10 transition metal compounds have been synthesized and characterized structurally, and some of them were characterized by magnetic measurements. This thesis contains three chapters: 1. Transition metal-azido coordination polymers with organic co-ligands(i) A 1D Mn(II)-azido coordination polymer was synthesized and characterized structurally and magnetically, in which Mn(II) ions are alternately bridged by double end-to-end (EE) and double end-on (EO) azido bridges. Magnetic analyses have revealed the existence of alternating ferromagnetic and antiferromagnetic interactions through the EO and EE azido bridges, respectively. (ii) A novel 2D Cu(II) coordination polymer, in which Cu(II) ions are linked by single EE azido bridges into chains and the chains are inlerlinked by l,3-bi(4-pyridine)propane. Magnetic analyses have revealed intrachain ferromagnetic interactions.(iii) Two isomeric Co(II) coordination polymers, one with a bilayer structure conaining two interpenetrated 2D grids and the other with a 1D ribbon structure, were characterized. This is a rare example of supramolecular isomerism due to the flexibility of 1,3-bi(4-pyridine)propane. (iv) A novel 1D Cd(II)-azido coordination polymer consisting of defect cubane units, in which Cd(II) ions are bridged by μ-1,1 and μ -1,1,1 azido ligands, were structurally characterized.2. The synthesis and structures of complexes with pyridazine-derived ligands Attemp to synthesize an achiral and octadentate polyiazine ligand, which had beenexpected to induce spontaneous resolution of chiral molecular magnets, give a mixture of three different ligands that are difficult to separate. Reacting the mixture with different metal ions have yieled complexes of different ligands. In this chapter, we decribed the structure of a mononuclear Zn(II) complex with a tridentate ligand, and a binuclear Cd(II) complex with a pentadentate ligands. The latter is a new type of binuclear double-strand helicate in which the ligand (strand) contains a tridentate and a bidentate coordination sites3. Supramolecular assembly of binuclear carboxylate-bridged complexesThe reaction of 2-phenyl-4-quinolinecarboxylic acid with copper nitrate and sulfate yieded two different compounds. Both compounds cotain paddle-wheel binuclear Cu₂(μ-COO)₄ units, but with different arrangement of the quinoline groups,...