Design,Synthesis And Magnetism Of Low Spin Fe~Ⅲ,Mn~Ⅲ Complexes | | Posted on:2017-11-20 | Degree:Doctor | Type:Dissertation | | Country:China | Candidate:X Chen | Full Text:PDF | | GTID:1311330536958751 | Subject:Chemistry | | Abstract/Summary: | PDF Full Text Request | | Currently,molecule magnets based on low-spin FeⅢ,MnⅢare still scarce.Distilling a classic structure from the series of coordination compounds mentioned above,magnetism-structure relation quantitatively modeling base on all main data dimensions were seldom reported.This thesis would concentrate on synthesis,structures and magnetism of coordination compounds based on low-spin FeⅢ,MnⅢ,and magnetism-structure relation quantitatively modeling on the system of low-spin FeⅢand high-spin MnⅢbridged by cyano group.The main content of the thesis is listed below:1.Based on FeⅢL12,MnⅢL12,MnⅢL22 components,a series of trinuclear,chainlike alternate low-spin and high-spin structure were obtained,while all of the complexes were antiferromagnetic.As a result,a syn-anti mode carboxylate bridge group would like to transfer antiferromagnetic coupling.All three chainlike complexes didn’t give any SCM behavior,which indicated antiferromagnetic made against construction of SCM.Another ligand was used to build a MnⅢdinuclear complex bridged by acid amide from the ligand.Unfortunately,the ligand could not stable low-spin state of MnⅢ,while the acid amide was still apt to transfer antiferromagnetic coupling.2.An alternate low-spin and high-spin MnⅢsingle chain bridged by cyano group was synthesized by controlling the environment of solvent.Magnetic analysis indicated the single chain structure behaved as an SCM,while an energy barrier was found higher than average of the ones reported before.A double relaxation processes also existed.The complex was reported as the first straight SCM with alternate low-spin and high-spin MnⅢ.Meanwhile,a series of low-spin FeⅢand NiIIchain were synthesized based on [Fe(im)(CN)5]2-and[Ni(L)]2+.Structural factors of magnetism based on this series were discussed in this part.3.In order to construct a effective magnetostructural correlation quantitatively modeling base on the system of low-spin FeⅢand high-spin MnⅢbridged by cyano group,structural data of 23 complexes reported were collected and sorted,bond index of the system was calculated by DFT methods,multiple linear regression was applied as main statistical mean.As a result,new quantitative model was developed to explain about 49.3% of the magnetic coupling constant’s change. | | Keywords/Search Tags: | molecule magnet, single chain magnet, coordination compound, low spin, magnetostructural correlation | PDF Full Text Request | Related items |
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