Design, Synthese, Structure And Magnetic Properties Of 3d Metal Compounds

Recently, there is an increasingly interest on the research of molecular-based material with the development of transitional metal complex as a new type of soft material. Molecular-based magnetic material may be used as the advanced technical material, especially as information storage material, because of the wider chemical selectivity of molecular-based magnetic material to the traditional magnetic material.In this thesis, appropriate transition metallic ions were chosen to react with the organic ligands and the other bridging ligands in order to prepare magnetic transition metal complexes. The concrete research content and the result brief elaboration are as follows:The azide bridging 1D copper (Ⅱ) and 3D cobalt (Ⅱ) coordination polymers have been synthesized by utilizing the rich coordination modes of the azide bridging ligands. In the 1D copper (Ⅱ) coordination polymer, the copper ions were connected by the azide groups in the form of EO (μ1,1-N3). The magnetic research indicated that the ferromagnetic interactions existed among the bridged metallic ions. In the 3D cobalt (Ⅱ) coordination polymer, the cobalt ions were connected by the azide groups in the form of EE(μ1,3-N3). The magnetic research indicated that the anti-ferromagnetic interactions existed among the bridged metallic ions. Additionally, CD spectroscopy indicates that 3D Cobalt complex is an infrequent example for single chiral complexes formed by achiral building blocks.By utilizing the rich coordination modes of the carboxylic groups and the azide groups, The binuclear chromium complex with the carboxylic group was synthesized through the hydrothermal method, and the binuclear and tetranuclear nickel complexes with the azide groups were synthesized by the homogenous phase method. In the binuclear chromium complex, Cr(Ⅲ) was assembled with 2,6 dipicolinic acid through the OH" bridge. The magnetic research indicated that the anti-ferromagnetic interaction exists in this complex. In the binuclear nickel complex, Ni(Ⅱ) was assembled with the Schiff base Hpmp by the azide group in the form of EO (μ1,1-N3). The magnetic research indicated that the ferromagnetic interactions existed between the bridged metallic ions. The tetranuclear nickel complexes were formed through the in situ assembly, and the azide group was connected with Ni(Ⅱ) as the terminal ligand.Based on the different coordination modes of various organic ligands, four single-nuclear complexes were synthesized by the assembly of the Schiff base ligand Pypa or the triazol ligands Dpta. The magnetic research indicated that the single-nuclear Mn complex ion has the spin-crossover effect. In the spin-crossover complexes studied currently, the spin-crossover of Fe(Ⅱ) is common. In this thesis, the infrequent Mn(Ⅲ) complex with the spin-crossover effect was studied. The achievement has a great theoretical significance on the research of the spin-crossover effect.