Synthesis, Structure And Magnetic Properties Of Diazido Cyclopentadienyl Diiron Complex

Molecule-based magnets are a class of materials showing spontaneous magnetization, and they are often synthesized at low tempreture with the method of organic, organometallic, coordination and polymer chemistry. The research on molecule-based magnets can help people get good understanding on substance’s magnetism. In addition, molecule-based magnets have excelent physical and chemical properties, and they show great potential in application of industrial fields. The investigations of OD, ID,2D and3D molecule-based magnets with end-on or end-end azide have become one of the most active fields in inorganic chemisry and materials science.In this thesis, in order to get OD molecule-based magnets with end-on azide, based on the novel dinuclear iron complexes [Cp*Fe(μ-SR)MeCN]2[PF6]2(Cp*=η5-CsMes, R=Me, la; R=’Pr. lb). a series of novel diazide dinuclear iron complexes[Cp*Fe(μ-SR)N3]2(2a;2b) were synthetized. The magntic properties of complex2a and2b were also investigated. The detailed contents are as follows:(1) Dinuclear iron complex la, lb and diazido dinuclear iron complex2a,2b were synthetized. Oxidation of [Cp*Fe(μ-SR)CO]2with NH4PF6in acetonitrile under air atmosphere produced complexes la and lb (yields la,43%; lb,41%). Complex2a and2b were obtained in high yield (2a,70%;2b,92%) during the reaction of complex la and lb with2eq. sodium azide at0℃. Complex la, lb,2a and2b were fully characterized by IR,1H NMR spectroscopies and single-crystal X-ray diffraction method.(2) Complex2a and2b were novel OD molecule-based magnets with terminal azide. They showed weak ferromagnetism due to spin-canting, and their spin-canting angles are0.11。and0.49。respectively. Interestingly, spontaneous magnetization was also observed in complex2b, which is one of the rare examples with similar structure.(3) The factors that influnce the magnetic behaviors of complex2a and2b were effects of terminal azide on coordination sphere of FeIII ions and the distance between the ions in the crystal structure. Novel OD molecule-based magnets with larger spin-canting angles and spontaneous magnetization can be expected by modifications of the structure complex2a and2b.