碱土金属与DBC-偶氮氯膦配位反应及配合物结构的研究

Studies on the Reaction and Structure of the Complexes of Alkaline Earth Metal with Chlorophosphonazo-DBC

本文研究了DBC-偶氮氯膦在不同酸度下的存在形式、质子化情况及反应中的质子释放情况,测定了钙、锶、钡与其形成的配合物的稳定常数.利用红外、激光Raman、核磁共振光谱等对所生成的配合物的结构进行了研究,并根据实验结果和分子结构的几种理论,提出了碱土金属与其生成的配合物的结构.本文还就配位反应和配合物的成键情况进行了讨论.

In this paper, the reaotion and structure of the complexes of alkaline earth metal (Ca, Sr, Ba) with 2-(4'-chloro-2'-phosphonazo)-7-(2', 6'-dibromo-4'-chlorophenylazo 1, 8-dihydroxy-3, 6-naphthalene disulfonic acid (Chlorophosphonazo-DBC) have been studied. This ligand has eight forms under different acidity. The protonation reactions take place at [H^+]>0.36mol·dm^(-3). The ligand begins dissociations at pH> 0.5. Two protons are released in the complexes formation reactions (Me^(2+)+2HI MeL_2 +2H^+). The stability constants of the complexes of Calcium, Strontium and Barium have been determined by Yoe-Jone method, Majumder-Chakrabartty method and calculation method. The order of the stability of complexes is as follows: Sr>Ba>Ca. The structure of the complexes have also been studied by infrared spectroscopy, Laser Raman spectroscopy, NMR, and EPR. The results show that these groups of N=N, PO_3H_2 and OH are active groups in the complex reactions. The structure of the complexes of Strontium, Barium and Caloium with chlorophosphonazo-DBC are represented and the reaotion and the complex bonds are discussed in this paper.