| Summary: | 碩士 === 淡江大學 === 化學學系 === 81 === The fundamental nature of spin-crossover phenomena for a series
of Fe(III)porphyrinate is studied. Crystal data of [Fe(TPP)(py)(
NCS).1/2py](py=pyridine) at 110 K : monoclinic; space group P21/
n, a=13.099(5), b=23.621(7), c=14.043(5)o .beta.=104.80(7).
degree. ,Dc=1.337 gcm-3, Z=4, .mu.=0.45 mm-1, R=0.079,
Rw=0.104. The aver age Fe-Np distance is 1.973 o; and the axial
Fe-Nncs and Fe-Npy distances are 1.917 o and 2.014 o,
respectively. By the measur ements of magnetic susceptibility,
EPR and Mssbauer, we strong ly believe that the series of
prophyrinate complexes are spin-crossover complexes. The EPR
spectra of the Fe(III)porphyrinate complexes show both the
high- spin and low-spin signals at 77 K and 298 K. The
effective magnetic moment of [Fe(TPP)(Py)(NCS).bul.1/2py] is
4.39 .mu.B at 300 K and decreases to about 3.89 .mu.B(100 K).
It is worth to note that the .mu.eff keeps constant from 100 K
to 8 K, and .mu.eff is 3.6 .mu.4.2 K. Furthermore, the Mssbauer
spectra for the series of porphyrinate complexes show two
doublets between 300 K and 77 K.
|
|---|
