Potentiometric and spectroscopic studies of the cobalt(II), nickel(II) and manganese(II) complexes with some aminodiphosphonic acids in aqueous solution
作者:Barbara Kurzak、Anna Kamecka、Krzysztof Kurzak、Julia Jezierska、Paweł Kafarski
DOI:10.1016/s0277-5387(00)00509-x
日期:2000.9
stoichiometries and stability constants of the manganese(II), cobalt(II) and nickel(II) complexes with seven aminodiphosphonates [RN(CH 2 PO 3 H 2 ) 2 , L] containing iminomethylenephosphonate moieties have been determined pH-metrically at 25°C and at an ionic strength of 0.20 mol dm −3 (KCl). The results suggest for L= 1 – 6 only equimolar species: [M(H 2 L)], [M(HL)] − , [ML] 2− and hydroxo [MH −1 L] 3− ,
摘要测定了7种含亚氨基亚膦酸酯基的氨基二膦酸酯[RN(CH 2 PO 3 H 2)2,L]的锰(II),钴(II)和镍(II)配合物的化学计量和稳定性常数。 25°C且离子强度为0.20 mol dm -3(KCl)。结果表明,在pH范围内,仅L = 1至6个等摩尔物质:[M(H 2 L)],[M(HL)]-,[ML] 2−和羟基[MH -1 L] 3−在3-11.5之间,唯一的区别是在低pH下,对于N -3- piclylyiminodiodi(亚甲基膦酸)酸还存在其他[M(H 3 L)] +物种。对于L = 7,模型包含质子化和非质子化的1:2物种。通过对稳定性和光谱数据(UV-VIS)的比较分析,可以确定配体仅通过膦酸酯基团以单齿或双齿方式与金属离子配位。从O-(PO 3 2-)到Ni 2+的LMCT波段在222-211 nm。