3,3,3-Trifluoro-N′-(3-trifluoromethylphenyl)-1,2-propanediamine and its N-mono-and N,N-dicarboxyethyl derivatives: synthesis, protolytic and complexation properties
作者:V. Yu. Korotaev、Yu. A. Skorik、A. Yu. Barkov、M. I. Kodess、A. Ya. Zapevalov
DOI:10.1007/s11172-006-0153-y
日期:2005.11
3,3,3-Trifluoro-N′-(3-trifluoromethylphenyl)-1,2-propanediamine (5) was synthesized by the reaction of 2-diazo-1,1,1-trifluoro-3-nitropropane or 3,3,3-trifluoro-1-nitropropene with 3-aminobenzotrifluoride followed by the reduction of the nitro group. The Michael 1,4-addition of diamine 5 to acrylic acid occurs only at the N(1) atom and affords N-mono-or N,N-dicarboxyethyl derivatives 6 and 7, depending on the reactant ratio. Protolytic equilibria 5–7 in aqueous solutions were studied by pH-potentiometry and UV spectroscopy. Only the aliphatic amino group can be protonated in an aqueous solution, while the aromatic amino group remains unprotonated even in 12 M HCl. The stability constants of transition metal (Cu2+, Ni2+, Zn2+) complexes with ligands 5–7 were determined by pH-potentiometric titration. The stability of the complexes and selectivity of the ligands toward Cu2+ ions increase with an increase in the number of N-carboxyethyl groups.
3,3,3-三氟-N′-(3-三氟甲基苯基)-1,2-丙二胺(5)是通过 2-重氮-1,1,1-三氟-3-硝基丙烷或 3,3,3-三氟-1-硝基丙烯与 3-氨基三氟甲苯反应,然后还原硝基而合成的。二胺 5 与丙烯酸的迈克尔 1,4-加成反应只发生在 N(1)原子上,并根据反应物的比例生成 N-单乙基或 N,N-二羧乙基衍生物 6 和 7。通过 pH 电位计和紫外光谱法研究了 5-7 在水溶液中的原生溶解平衡。在水溶液中,只有脂肪族氨基能被质子化,而芳香族氨基即使在 12 M HCl 中仍未被质子化。通过 pH 电位滴定法测定了过渡金属(Cu2+、Ni2+、Zn2+)与配体 5-7 的配合物的稳定性常数。随着 N-羧乙基数量的增加,配合物的稳定性和配体对 Cu2+ 离子的选择性也随之增加。