Syntheses and characterization of atr base Fe(Ⅱ) spin crossover complexes
Date Issued
2005
Date
2005
Author(s)
Liu, Chi-Tsun
DOI
zh-TW
Abstract
A new ligand, trans-4,4`-azo-1,2,4-triazole (atr) was designed and synthesized to construct the possible candidates for spin crossover system.
The ligand is a planar molecule with two 1,2,4-triazole linked by an azo group. It could be served as a multi-dentate ligand or a good linkage ligand. A series of Fe(II) polymeric compounds in 1D, 2D and 3D frameworks have been successfully synthesized and studied structurally and magnetically. The crystal structures of the ligand and the series of polymeric Fe(II) complexes will be presented. In all the complexes, each ligand atr serves as a bridge between two Fe(II) centers; There are water molecules and NCS ligand around each Fe(II) in the 1-D polymeric
compound, [Fe(µ-atr)(NCS)2(H2O)2]; An additional bridge ligand,pyz, is used to form a rectangular 2D framework, [Fe(µ-atr)(µ-pyz)(NCS)2]．4H2O. A cationic species with Fe to atr ratio of 1 to 3 is formed
in a 3D framework with the perchlorate as the inclusion counter anions,[Fe(µ-atr)3](ClO4)2．2H2O, the structure shows a interlock network. The magnetic properties are quite interesting: It is ferromagnetic for the 1D
system but display spin transitions for both 2D and 3D systems. It exhibits an abrupt spin transition at Tc= 227 K for [Fe(µ-atr)(µ-pyz)(NCS)2]．4H2O. However, it shows a two-step spin transition for the 3D frameworks [Fe(µ-atr)3](ClO4)2．2H2O. The crystal structures at various
spin states will be compared.
Subjects
自旋交叉錯合物
spin crossover
Type
thesis
File(s)![Thumbnail Image]()
Loading...
Name
ntu-94-R92223045-1.pdf
Size
23.31 KB
Format
Adobe PDF
Checksum
(MD5):29a52e66535acea92347d0277a42952b