摘要
该文对Cd-HEDTA(N-(2-羟基乙基)乙二胺-N’,N’,N’-三乙酸),Cd-PDTA(1,2丙二胺四乙酸)和Cd-DTPA(二乙三胺五乙酸)的^(113)Cd NMR谱和自旋晶格弛豫时间T_1,及NOE因子进行了研究.结果表明,Cd-HEDTA和Cd-PDTA结构与Cd-EDTA类似,Cd-PDTA双线归因于其可能的两种异构体.Cd-DTPA大的化学位移表明其具有七配位的五角双锥结构.在这种结构中DTPA可用三个氮原子参加配位.对^(113)Cd自旋晶格弛豫时间分析表明,Cd-DTPA配合物中质子偶极作用机理的贡献较大,这归因于Cd DTPA有更多的乙酸根亚甲基质子参与偶极作用。
113Cd NMR spectra have been obtained on several Cd - polyaminocarboxylic acid complexes Cd-N- (2 - Hydroxycthyl) ethylene diaminetriacetate (Cd-HEDTA), Cd-1,2-Propanediaminetetraacetate (Cd-PDTA) and Cd - Diethylenetriaminepentaacetatc ( Cd-DTPA). The spectra revealed that Cd-HEDTA and Cd-PDTA have the same solution structure as the Cd-EDTA. The two lines of Cd-PDTA spectrum come from its two isomers and are indicative of the existance of more strained structure having the axial CH3 group . The large chemical shift of Cd-DTPA shows that it is seven coordinated because in that case, three nitrogen atoms rather than two are bound to Cd atom. 113Cd nuclear Ovcrhauscr effect, η, and spin lattice relaxation time were determined for Cd-DTPA and Cd-HEDTA and used in the analysis of the contribution to the relaxation mechanism from the dipolar interaction with protons.
出处
《波谱学杂志》
CAS
CSCD
1992年第1期67-73,共7页
Chinese Journal of Magnetic Resonance
基金
国家自然科学基金资助课题
关键词
胺羧
配合物
NMR
镉113
113Cd NMR
Polyaminocarboxylate-Cadmium complexes
