日本电子顺磁共振波谱用户资料.ppt

Some ESR Experimental Results in our Laboratory Chen Jiafu jfchen@ustc.edu.cn Hefei National Laboratory for Physical Sciences at Microscale, EPR/ESR LabUSTC 2012. 10. 13, Beijing 253K—373K Acknowledgement： Dr. Zhu Chunhua, Dr. Yang Jiahui Collaborator： Prof. Su Jihu, Prof. Zhu Xinbao Some interesting examples: Green line: intermediate state Red line: Red line: Black line: Zn+ ① ② ① ② Cube Green lines: in D2O Black lines: in H2O Red lines: adding Carotene 2,2,6,6-Tetramethyl-4-piperidone HydrochlorideTMP, trap for singlet O2 Octahedron Research on Giant Magnetoresistance materials by ESR BixCa?Cu1-xO? Angular Rotation Experiments: Part 1. In situ Variable Temperature ESR Characterization of Thermodynamics of Singly-bonded C60 Fullerene Dimer Variable Temerature ESR : Synthesis experimental section: Chlorobenzene, 135℃, Mn(OAc)3, Ar, product yield ~88% G.W. Wang, C.Z.Wang et al Chem. Commun., 2011, 47, 6111 Fig. X-ray crystal structure of the predominant component (the meso isomer) of 2a. Thermal ellipsoids are drawn at 50% probability level. The reversible dissociation of the (C60)2-(P(O)(OMe)2)2 dimer at 373K even to higher P: I=1/2 Hyperfine Coupling：2nI+1 = 2 The continuous-wave (cw) in situ ESR measurements were performed on a JES-FA200 X-band (9.087 GHz, JEOL) ESR spectrometer equipped with a cavity which is capable of varying the temperature from 105 K to the maximum of 473 K. Figure 1. Experimental (black) and simulated (red) EPR spectra of the formed monomer ●C60P(O)(OMe)2 radical dissociated from dimer in ODCB at 373K Temperature dependence Experiments: Microwave power dependence: I is the EPR signal amplitude, I0 the maximum amplitude, and C0 the concentration of the original dimer before the heating treatment. BDE (Bond Dissociation Enthalpy or ΔHo) is obtained by fitting the experimental data with van’t Hoff’s equation. Zheng, S.J., et al., Journal of the American Chemical Society, 2003. 125(19):