论文部分内容阅读
本文用核磁共振法(NMR)和pH法对Zn(Ⅱ)与1-羟基乙叉-1,1-二膦酸(1-hydroxyethylidenel,1-diphosphonic acid,简称HEDP,以H_4L表示)的配合物进行了研究,由于pH<7时溶液中有沉淀生成,故NMR的研究是在溶液pH>7时进行.测定了溶液中不同Zn(Ⅱ)/HEDP摩尔比和pH值时~(?)PNMR的化学位移。研究结果表明在pH7.5-11.0范围内生成Zn(Ⅱ)/HEDP=1(摩尔比)组成的配合物,在pH11.8-12.3范围内生成Zn(Ⅱ)/HEDP=2(摩尔比)组成的配合物,分别用pH法和NMR法测定了上述组成配合物的稳定常数.结果如下: logK_([zn(HL)~-]) logK_([znL~(2-)]) logK_([zn,L]) pH法 4.69 7.51 11.63 NMR法——6.88-7.19 12.44
In this paper, the complexes of Zn (Ⅱ) and 1-hydroxyethylidenel (1-diphosphonic acid, HEDP, H_4L) were characterized by nuclear magnetic resonance (NMR) As a result of the precipitation in the solution at pH <7, the NMR study was carried out at a solution pH> 7. The molar ratios of different Zn (II) / HEDP and pH (~) PNMR Chemical shift. The results show that Zn (Ⅱ) / HEDP = 2 (molar ratio) is formed in the range of pH11.8-12.3 at pH7.5-11.0, , The stability constants of the above complexes were determined by pH and NMR respectively.The results are as follows: logK _ ([zn (HL) ~]] logK _ ([znL ~ (2-)]) logK _ zn, L]) pH method 4.69 7.51 11.63 NMR method - 6.88-7.19 12.44