Bridging Multicore Chrome Synthesis And Magnetic Properties Of Complexes

There have been numerous experiments on animals and clinic tests confirming trivalent chromium is an essential micronutrient for human and animals, which can affect the metabolism of glucose. Chronic ions exist in organism in the form of glucose tolerance factors(GTF), which are likely to stimulate the metabolism of glucose and lipid through increasing the appetency of insulin, the number of insulin receptor and the function of P cell. Investigations have indicated that chromium complexes hold the balance role in the design of new molecular-base magnetic materials and catalyzer of polyethylene production as well as medication.In this thesis bridged multinuclear chromium complexes have been studied starting from glucose tolerance factors. Eighteen heterometallic multinuclear complexes with 1. 10-phen, 2, 2-bipy, ox, RCOO- as ligands containing iron, cooper, nickel, et al, two salen mononuclear complexes and three oxo-bridged trinuclear complexes have been synthesized, their structures have been ascertained by C, H, N element analysis, Infrared spectrum, Raman spectrum, UV-vis spectrum.In the Infrared spectrum of complexes, there are strong absorptions in ~1 660 cm-1 which can be ascribed to the antisymmetric vibration of the O -C -O unit in heterometallic multinuclear complexes. The different dates of antisymmetric stretching vibration of ox present two modes. There are absorption in ~650 cm-1 which can be ascribed to the Cr3O unit hi trinuclear chromium complexes. Some characteristic peaks in Raman spectrum have been pointed out.In the UV-vis spectrum of complexes, the absorption of [CrN2O2] d -d transtion at about ~400 nm and 530~550 nm in heterometellic multinuclear complexes, which is the same to the date of some glucose tolerance factors models. The absorptions at ~440 nm, 573~590 nm in trinuclear is resigned to oxo-Cr(III) charge transfers. Comparing the splitting energe, 0, repulsion parameters B' and values, ligand field stabilizational energes, and curving parameters c value acquires the serial of electron cloud expanding and the order of photochemistry for correlated ligands.4. The magnetic susceptibilities result of mononuclear complexes C17H16CrN3O7Cl2(C2) and C2oH3oO9N3Cr(C8) suggests an weak magnetic interaction between moleculars with J= 1.288 cm-1 (C2) and 1.249 cm-1(C8), g=2.05(C2) and 2.00(C8).5. A theoretical quantum calculation study by the DFT-B3LYP method, effect core potential basis set LANL2DZ have been carried out for [Cr(mal)2(H2O)2]- (A), [Cr(mal)(H2O)4]+ (B),[Cr(phen)(ox)2]- (C), [Cr(phen)(ox)(H2O)2]+ (D), and [Cr(salen)(H2O)2]+(E), hoping to obtain a better understanding of these mononuclear complexes. Discussing Their differences of energy, distribution of charge, infrared spectrum, etc, have been discussed and the conclusion that the different ligands on the axes have great effect on the complexes' properties have been gained.