摘要
相同卟啉配体与不同金属离子形成的配合物的稳定性取决于金属离子的性质。根据金属离子的结构及金属与卟啉的配位模式等关系对其电子光谱图的不同，作者提出了判断金属卟啉稳定性的依据，即测定该配合物的电子光谱显示的Ｓｏｒｅｔ谱带。实验测得各个金属卟啉的Ｓｏｒｅｔ带红移顺序与稳定系数大小基本一致。
The absouption epectra of porphrins,metalloporphyrins and their derivatives are part of their moot useful and most important properties,and are corretated with many physicochemical properties. Factors which encrourage increases in π-electron density at the periphery of the porphyrin nucleus cause shifts to longer wavelength in the absorption bands,and the fluorescence emission bands if present,of porphyrins,and their metal chelates and other complexes. Thus shifts to longer wavelength are found as the electron-attracting power of side-chains increases and as the stability of porphyrin chelated with different metal ions decreases;A charge-transfer band at about 630 nm is found in the high-spin but not in the lowspin complexes. The stable chelates with metals such as Ni(Ⅱ),Co(Ⅱ),Cu(Ⅱ),have the order of intensities α>β,while in the less stable chelates,such as those with Mg(Ⅱ),Zn(Ⅱ),cd(Ⅱ)Mn(Ⅱ),the orden is reversed. Little quantitative information is available on the rates of incorporation of different metal ionr unden comparable conditions, In aqueoue Solution, Cu(Ⅱ)is the most rapidly incorporated ion followed by Zn(Ⅱ),Co(Ⅱ),Fe(Ⅱ) and Ni(Ⅱ).The kinetic order does not correspond to the thermodvnamic stability order Ni(Ⅱ)>Co(Ⅱ)>Cu(Ⅱ)>Fe(Ⅱ)>Zn(Ⅱ)>Mg(Ⅱ).The Soret bands of some few sodiummetallochlorophyllins which change to longer wavelength are similar to the thermodynarnic stability order and the order of stable coefficients SM of some metalloporphyrins.
出处
《华西药学杂志》
CAS
CSCD
北大核心
1995年第1期15-17,共3页
West China Journal of Pharmaceutical Sciences
关键词
Lei族化合物
金属卟啉
稳定性
电子光谱
叶绿酸a
Metalloporphyrins Sodium-metallochlorophyllins Trace elements Soret band Stable coefficient SM
