当前位置: X-MOL 学术J. Mol. Liq. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Sequestration of HEDPA, NTA and phosphonic NTA derivatives towards Al3+ in aqueous solution
Journal of Molecular Liquids ( IF 5.3 ) Pub Date : 2018-04-05
Paola Cardiano, Concetta De Stefano, Claudia Foti, Fausta Giacobello, Ottavia Giuffrè, Silvio Sammartano

The sequestration of Al3+ by etidronic acid (1‑Hydroxyethane‑1,1‑diyil)bis(phosphonic acid) (HEDPA), nitrilotriacetic acid and its phosphonic derivatives, namely N‑(phosphonomethyl)iminodiacetic acid (PMIDA, NTAP), N,N‑bis‑(phosphonomethyl)glycine (NTA2P) and [bis(phosphonomethyl)amino]methylphosphonic acid (NTA3P) was studied in aqueous solution at T = 298.15 K and I = 0.15 mol L−1 in NaCl. Formation constants and speciation models are discussed on the basis of potentiometric results. The speciation models found for all the systems include MLH, ML and MLOH species, in addition for Al3+-NTA system ML(OH)2 and M2L2(OH)2, for NTAP system ML2, for NTA2P and NTA3P systems MLH2 species, for HEDPA system ML2 and ML2OH species were detected as well. The formation constant values for ML species show the trend NTA < NTAP < HEDP < NTA2P < NTA3P. Investigations using 1H NMR spectroscopy were also performed for the study of Al3+-NTAP system. The 1H NMR findings are in agreement with the speciation model obtained by potentiometry, confirming the stabilities of the main species. The dependence of formation constants on ionic strength over the range I = 0.15 to 1 mol L−1 in NaCl is also reported for NTA, NTAP, NTA2P systems. Enthalpy change values obtained by titration calorimetry at T = 298.15 K and I = 0.15 mol L−1 in NaCl, for the main Al3+-NTA, -NTAP, -NTA2P and NTA3P species, are mainly endothermic, as typical for hard-hard interactions. The sequestering ability of the ligands under study towards Al3+ was also evaluated, under different pH conditions by the empirical parameter pL0.5.



中文翻译:

水溶液中HEDPANTA和膦酸NTA衍生物对Al 3+的螯合。

乙二胺四乙酸(1-乙氧基乙烷-1,1-二乙腈)双(膦酸)(HEDPA),次氮基三乙酸及其膦酸酯衍生物,即N-(膦酰基甲基)亚氨基二乙酸(PMIDA,NTAP),对Al 3+的螯合,在水溶液中,在T  = 298.15 K和I  = 0.15 mol L -1的条件下研究了NN-双-(膦酰基甲基)甘氨酸(NTA2P)和[双(膦酰基甲基)氨基]甲基膦酸(NTA3P)。在氯化钠中。在电位测量结果的基础上讨论了形成常数和形态模型。找到的所有系统的形态模型包括MLH,ML和MLOH物种中,除了用于铝3+ - NTA系统ML(OH)2和M 2大号2(OH)2,用于NTAP系统ML 2,用于NTA2PNTA3P系统MLH 2种类,对于HEDPA系统也检测到ML 2和ML 2 OH种类。ML物种的形成常数值显示趋势NTA  <  NTAP <  HEDP  <  NTA2P  <  NTA3P。使用调查1个也为Al的研究中进行的1 H NMR光谱3+ - NTAP系统。的1个1 H NMR发现与通过电位获得,证实主要种类的稳定性的形态模型的协议。对于NTANTAPNTA2P系统,还报道了在NaCl中,在I  = 0.15至1 mol L -1范围内,形成常数对离子强度的依赖性。通过滴定量热法在T  = 298.15 K和I下获得的焓变值 = 0.15摩尔大号-1在NaCl,对于主铝3+ - NTA,-NTAP,-NTA2PNTA3P物种,主要是吸热的,作为典型的硬-硬相互作用。还通过经验参数pL 0.5评估了在不同pH条件下所研究的配体对Al 3+的螯合能力。

更新日期:2018-04-06
down
wechat
bug