摘要
测定了各pD值下BPHA[BPHA是N,N’-bis(2-aminoethyl)-1,3-propanediamine hexaaceticacid的简称,中文名称为二胺乙基丙二胺六乙酸]和Zn^(2+)-BPHA的~1H NMR谱.BPHA两端羧甲基上亚甲基质子的化学位移δ_a和中间羧甲基上亚甲基质子的化学位移δ_b随PD值交替变化.Zn^(2+)-BPHA的~1HNMR谱有3种情况:pD<6,对应Zn(Ⅱ)-H_2BPHA^(4-),有一特征尖峰,显示自由-NH^+(CH_2COO^-)_2残基存在;pD=6～9,对应Zn(Ⅱ)-HBPHA^(5-),该峰消失,显示4个胺基全部配位;pD>9,对应Zn(Ⅱ)-BpHA^(6-),该峰再次出现,1个N(CH_2COO^-)_2脱离配位体系.在3种形态的配合物中,Zn—N键都是非活性的,Zn—O键在后两种形态配合物中是非活性的.
The 1H NMR spectra of BPHA and Zn( II ) - BPHA have been determined in the pD range 0.8-12.4. In contrast to DTPA and TTHA, the chemical shifts of the methylene protons a in the terminal carboxymethyl groups and b in the middle carboxymethyl groups of BPHA change alternatively with the increasing pD value. For Zn( II ) - BPHA, there are three kinds of 1H NMR spectra. In the range pD < 6, there exists a sharp peak characteristic of a free NH+ (CH2COO- )2 moiety. From 6 to 9, no sharp single peak exists indicating all nitrogen atoms are coordinated; After pD > 9, a sharp single peak appears at 3. 14 indicating that an iminodiacetate group is again free except the nitrogen is not protonized.
出处
《化学学报》
SCIE
CAS
CSCD
北大核心
1999年第6期616-621,共6页
Acta Chimica Sinica
关键词
胺羧配位剂
NMR
配合物
锌
结构
BPHA
polyaminopolycarboxylic acid, 1H NMR spectra, complex, zinc, structure.
