Synthesis, Structure And Magnetic Properties Of Manganese (â…¢) Complexes With Chiral Schiff Base

Coordination compounds with chiral Schiff-base ligands and Mn(III) ion havevarious structures and excellent properties, which they are widely used in the relatedfields such as chiral catalysis, biotechnology and functional materials. The higherrequirement on the material properties in many areas and the rapid development ofscience and technology lead to the growth of application of multifunctional materialswith ferromagnetism, ferroelectricity, luminance and other properties. Based on theabove background, a series of chiral Schiff base ligands was synthesized through thereaction of chiral cyclohexanediamine and salicyladehyde derivatives, then thesechiral Schiff base ligands were used to synthesize the chiral complexes with Mn(III).The single crystals of the Mn(III) complexes with chiral Schiff-base ligands wereobtained through using azide ion (N3-), modified cyano-metallic complexes, such as[(Tp)Fe(CN)3]-,[(BuTp)Fe(CN)3]-,[Fe(CN)6]3-and [Cr(CN)6]3-as bridging groups，and the crystal structures and properties were studied through the infraredspectroscopy, CD spectra, magnetic measurement. The main contents and results inthis thesis are as follows:(1) A series of chrial Schiff-base complexes, Mn(R or S–L1) ClO4·2H2O、Mn(Ror S–L2) ClO4·2H2O, Mn(R or S–L3) ClO4·2H2O, were obtained by the reaction ofMn(III) and the chiral Schiff-base ligands that synthesized through the chiralcyclohexanediamine and salicylaldehyde with different substituent on5th position.(2) Six azido-bridged one-dimensional chain complexes,[Mn(R or S–L1(N3)]n(1,2),[Mn(R or S–L2(N3)]n(3,4),[Mn(R or S-L3(N3)]n(5,6), are obtained by thereaction of azide(N3-) ion and chiral complexes Mn(R or S–L1) ClO4·2H2O, Mn(R orS–L2) ClO4·2H2O, Mn(R or S–L3) ClO4·2H2O. They are crystallized in themonoclinic system. Among these, complexes1and2crystallize in the center spacegroup of P21/c,3and4crystallize in the chiral space group of P21,5and6crystallizein the chiral space group of P212121. The structures was analyzed by X-ray singlecrystal diffraction, infrared spectroscopy and CD spectra. Magnetic studies showedthat complexes2,4,6have similar magnetic behaviors, and they are all typicalantiferromagnetic compounds.(3) Compounds7and8are a pair of chain complexes, which obtained by thereaction of modified cyanometallic compounds (Bu4N)[(Tp)Fe(CN)3] and Mn(R or S–L3) ClO4·2H2O. They are both crystallized in P1chiral space group of triclinic system, and the structures are proved further by X-ray single crystal diffraction,infrared spectroscopy and CD spectra. Magnetic studies show that the complexes7and8are magnetic, and their magnetic behaviors are from a weak ferromagneticexchange turn into antiferromagnetic. Two dual-core complexes9and10wereformed by reaction between (Bu4N)[(BuTp)Fe(CN)3] and Mn(R or S–L2) ClO4·2H2O,which are crystallized in P-1center symmetric space group of triclinic system.(4) One dimensional chain complexes11were synthesized by reaction of(Bu4N)Fe(CN)6and Mn(R or S–L1) ClO4·2H2O（n/n=1:3）；complexes12weresynthesized by reaction of (Bu4N)Cr(CN)6and Mn(R or S–L2) ClO4·2H2O(n/n=1:3).Complexes11crystallized in C2/c center symmetric space group of monoclinicsystem, and Complexes12crystallized in P-1space group of triclinic system. Thestructures is determined by X-ray single crystal diffraction, and further confirmed byinfrared spectroscopy and CD spectra.