Aminoalkyl‐1,1‐bis(phosphinic acids): Stability, Acid–Base, and Coordination Properties
作者:Tomáš David、Soňa Procházková、Jan Kotek、Vojtěch Kubíček、Petr Hermann、Ivan Lukeš
DOI:10.1002/ejic.201402420
日期:2014.9
Four geminal bis(phosphinic acids), namely, aminomethylbis(H-phosphinic acid) (H2L1) and 4-aminobutyl-1-hydroxy-1,1-bis(R-phosphinic acid) with R = H (H2L2), Me (H2L3) and CH2CH2COOH (H4L4), were studied. Their acid–base properties and coordination ability towards Cu2+, Ni2+ and Zn2+ ions were studied by potentiometry, UV/Vis spectroscopy and NMR spectroscopy. The amine group in H2L1 has a lower protonation
四种孪生双(次膦酸),即氨基甲基双(H-次膦酸)(H2L1)和4-氨基丁基-1-羟基-1,1-双(R-次膦酸),其中R=H(H2L2),Me( H2L3) 和 CH2CH2COOH (H4L4) 进行了研究。通过电位测定法、紫外/可见光谱和核磁共振光谱研究了它们的酸碱性质和对 Cu2+、Ni2+ 和 Zn2+ 离子的配位能力。H2L1 中的胺基团的质子化常数 (log Ka = 6.79) 比其他研究的双次膦酸盐 (log Ka = 10.75–11.05) 中发现的质子化常数更低 (log Ka = 10.75–11.05)。[Ca(H2L2-O,O')(HL2-O,O')]Cl 的结构揭示了金属配位球的八面体排列和线性聚合物结构,它通过八元 Ca(-O-P –O–)2Ca 环。[Cu(HL3-O,O')2(H2O)]·5H2O的结构在赤道O4环境中显示出两个螯合的双次膦酸酯基团。