Containing Pyridine, Pyrazine, And Quinoline Heterocyclic Ligand Synthesis And Properties Of Complexes

This dissertation deals with the designs and syntheses of six unpublished complexes, namely, one-dimensional chain complex {[Co(μ-Dpd)(Q)₂(H₂O)₂]·2(ClO₄)}n (1) with 2,5-dimethylpyrazine-2,5-dioxide as bridge ligand and 8-hydroxylquinoline N-oxide as terminal ligand; three mono-nuclear complexes [Co(HCPy)₂(H₂O)₂] (2); [Mn(HCPy)₂(H₂O)₂] (3) and [Zn(HCPy)₂(H₂O)₂] (4) with 2-oxidopyridinium-3-carboxylato (HCPy) as ligand, and two mono-nuclear complexes [Cd(MPE)Cl₂] (5) and [Cu(MPE)Cl][Cu(MPE)(H₂O)Cl]·2(ClO₄) (6) with 2,2'-oxydi(methylene)dipyridine (MPE) as three-dentate bridge ligand.This dissertation also deals with the characterizations for the complexes with infrared spectra, elemental analyses and X-ray crystallography. This dissertation includes the magnetic study for one-dimensional chain complex {[Mn(μ-Dpd)(Q)₂(H₂O)₂]·2(ClO₄)}n (7). The magnetic study reveals that there are two pathways for magnetic coupling. One is through the bridge ligand, and another one deals withπ-πstacking which is from 8-hydroxyquinoline N-oxide of neighbor chains. DFT calculations reveal that there are anti-ferromagnetic interaction and ferro-magnetic interaction between bridged Mn(Ⅱ) ions with 2,5-dimethylpyrazine-1,4-dioxide as bridge ligand, and the anti-ferromagnetic interaction is due to spin delocalization and the ferromagnetic interaction is attributed to the spin polarization, and the anti-ferromagnetic interaction is stronger than that of the ferro-magnetic interaction. Theπ-πstacking results in ferromagnetic interaction. A fitting for the variable-temperature magnetic susceptibility with one-dimensional chain formula gave the coupling constant J = -0.07 cm^-1. Study with structural characters for other six complexes was made and the relevant structural information was obtained.The distinguished feature and contribution of this dissertation lies in that the dissertation studied the magnetic coupling mechanism and the magnetic coupling intensity of aπ-πstacking system by using density functional calculations, which has not been reported as yet.The results of this dissertation will benefit the synthesis of ideal molecular-ferromagnet and it will also benefit the research of bio-function of metal protein that deals with bridged metal ions.