N,N'-双(2-氨基苯甲酰基)-1,3-丙二胺的合成及其配合物稳定常数

Synthesis of N,N'-bis(2-aminobenzoyl)-1,3-propane Diamine and Stability Constant on Its Metal Complexes

首次合成一种链式苯并酰胺配体Ｎ，Ｎ＇－双（２－氨基苯甲酰基）－１，３－丙二胺．用元素分析，红外，紫外－可见光，核磁共振等对配体进行表征和确证．用ｐＨ－电位法测定了配体的加质子常数βＨ１及其４种过渡金属离子所形成的去质子ＭＨ－２Ｌ型配合物的稳定常数Ｋ．结果，βＨ１＝２．４２×１０２，βＨ２＝４．１５×１０３；ｌｏｇＫ分别为：－９．８３（Ｃｕ２＋）；－１３．７６（Ｎｉ２＋）；－１４．１３（Ｃｏ２＋）；－１２．１２（Ｚｎ２＋）．配位情况类似于低肽的配合物，且形成１∶１的中性分子，稳定性顺序Ｃｏ２＋＜Ｎｉ２＋＜Ｃｕ２＋＞Ｚｎ２＋，和Ｌｒｖｉｎｇ－Ｗｉｌｉａｍｓ顺序一致．

N,N'-bis(2-aminobenzoyl)-1,3-propane diamine was synthesized and characterized by EA, IR, UV-Vis, and 1HNMR, the measured m.p. being 166℃. Protonaton constants of the ligand and stability constants of its complexes with four metal ions were determined by pH-potentiometric method in water, at 26℃,ionic strengh I=0.2(NaClO 40). CalCalculated results were as follows: logK CuH-2 L=-9.83;logK NiH-2 L=-13.76;logK CoH-2 L=-14.13;logK ZnH-2 L=-12.12.The cumulative protonation constants under the same conditions were β H 1=2.24×10 2;β H 2=4.15×10 3.The circumstances resemble oligopeptide.The ligand was found to form 1∶1 neutral complexes with metal ions.The stabilities of complexes were in the order of Co<Ni<Cu>Zn, being in concordance with Irving-Williama order.