Synthesis And Characteristic Of The Spin-crossover Coordination Polymer Compounds

In the thesis, we designed several novel polymer coordination compounds that possess spin-crossover (SCO) performance via different chemical synthesis and polymerization methods, in order to improve their spin-crossover performance and make it possible for them to become information storage materials. The structure and properties of the polymer ligand and the coordination compounds were characterized by means of Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance of hydrogen spectrum (’H-NMR), X-ray diffraction (XRD), superconducting quantum interference device (SQUID) and differential scanning calorimetry (DSC). The main work is given as follows:1. The synthesis of the spin-crossover coordination compounds respectively containing the main chain of methacrylamide and acrylamide:4-amino-1,2,4-triazole was respectively reacted with methacryloyl chloride and acryloyl chloride in the solution of acetonitrile to obtain the monomer. The monomer was polymerized through atom transfer radical polymerization (ATRP) by using 2-bromoisobutyric acid ethyl ester as initiator, copper(Ⅰ) chloride and 2,2’-dipyridyl as initiating system, and acetonitrile as solvent, to get the ligands containing the main chain of methacrylamide or acrylamide. The ligands were coordinated with ferrous chloride in the solution of methanol to obtain the coordination compounds owning spin-crossover performance. The products were characterized by FT-IR,1H-NMR and XRD. The measurements of SQUID and DSC prove that the coordination compound with the main chain of methacrylamide owns relatively better spin-crossover performance than the one containing the main chain of acrylamide.2. The synthesis of the spin-crossover coordination compounds containing the main chain of polyethylene glycol (PEG) which were terminated by triazole:Chloroacetyl chloride was reacted with PEG-400, PEG-600 and PEG-800 respectively, then the resultants were reacted with 4-amino-1,2,4-triazole. The obtained ligands were coordinated with ferrous chloride in the solution of methanol to get coordination compounds that possess the spin-crossover performance. The products were characterized by FT-IR and 1H-NMR. The measurements of SQUID and DSC show that the product from PEG-400 is liquid and exhibits no spin-crossover phenomenon. In comparison with the product from PEG-800, the one from PEG-600 possesses a transition temperature closer to the room temperature and wider hysteresis width.3. The synthesis of the spin-crossover coordination compound with the main chain of bisphenol A epoxy resin being double-terminated by triazole:The 4-amino-1,2,4-triazole was reacted with bisphenol A epoxy resin in the mixed solution of methanol and acetone to get ligand. The ligand was coordinated with ferrous chloride in the mixed solution of methanol and acetone to obtain the coordination compound owning spin-crossover performance. The compound was characterized by 1H-NMR, and its spin-crossover performance was tested by means of SQUID and DSC. The results show that the coordination compound exhibits certain spin-crossover performance.