The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3'-dimethyl-1-(1H-1,2,4-triazol-1- yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X = Br or Cl) in a nitrogen atmosphere were studied un-der the ...The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3'-dimethyl-1-(1H-1,2,4-triazol-1- yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X = Br or Cl) in a nitrogen atmosphere were studied un-der the non-isothermal conditions by simultaneous TG-DTG-DSC, EDS and elemental analysis techniques. The re-sults showed that their decomposition proceeded in three different ways mainly depending on the anions in the molecules. The heat effect associated with the decomposition step of DMTZB molecules was also different. The decomposition mechanisms and the kinetic parameters of DMTZB were determined and calculated by jointly using four methods, which showed that its pyrolysis was controlled by D3 mechanism but with different activation ener-gies and pre-exponential factors for different complexes.展开更多
Synthesis and characterization of the ligand, 10-(-hexadecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane- 1,4,7-triacetic acid (H4L), and its Gd(III) chelate are described. Protonation constants for H4L (HlgiK=10.52,...Synthesis and characterization of the ligand, 10-(-hexadecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane- 1,4,7-triacetic acid (H4L), and its Gd(III) chelate are described. Protonation constants for H4L (HlgiK=10.52, 9.45, 4.74, 4.10) and the stability constant for GdL- (-GdLlg K=24.50) were determined by potentiometric titrations. The results obtained show that the ligand still maintains the strong chelating properties of the parent DOTA (1,4,7,10-tetraazacyclododecane-N,N',N''N'''-tetraacetic acid) after introduction of a linear chain hexadecyl group at the acetic side chain of DOTA, and its basicity is not significantly altered.展开更多
文摘The thermal behaviors of the complexes of Cu(DMTZB)4X2 (DMTZB=3,3'-dimethyl-1-(1H-1,2,4-triazol-1- yl)-2-butanone, X=NO3 or ClO4) and Cu(DMTZB)2 X2 (X = Br or Cl) in a nitrogen atmosphere were studied un-der the non-isothermal conditions by simultaneous TG-DTG-DSC, EDS and elemental analysis techniques. The re-sults showed that their decomposition proceeded in three different ways mainly depending on the anions in the molecules. The heat effect associated with the decomposition step of DMTZB molecules was also different. The decomposition mechanisms and the kinetic parameters of DMTZB were determined and calculated by jointly using four methods, which showed that its pyrolysis was controlled by D3 mechanism but with different activation ener-gies and pre-exponential factors for different complexes.
基金Project supported by the Department of Science and Technology of Hunan Province (No. OOSSY 1013-51).
文摘Synthesis and characterization of the ligand, 10-(-hexadecylcarboxymethyl)-1,4,7,10-tetraazacyclododecane- 1,4,7-triacetic acid (H4L), and its Gd(III) chelate are described. Protonation constants for H4L (HlgiK=10.52, 9.45, 4.74, 4.10) and the stability constant for GdL- (-GdLlg K=24.50) were determined by potentiometric titrations. The results obtained show that the ligand still maintains the strong chelating properties of the parent DOTA (1,4,7,10-tetraazacyclododecane-N,N',N''N'''-tetraacetic acid) after introduction of a linear chain hexadecyl group at the acetic side chain of DOTA, and its basicity is not significantly altered.
