Ansari Seraj Ahmad, Gujar Rajesh Bhikaji, Mohapatra Prasanta Kumar
Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai - 400 085, India.
Dalton Trans. 2017 Jun 13;46(23):7584-7593. doi: 10.1039/c7dt01090g.
This paper reports the complexation of a series of tetraalkyl diglycolamides (TRDGA) with trivalent f-cations in a room temperature ionic liquid, viz., 3-octyl-1-methylimidazolium bis(trifluoromethanesulfonyl)imide ([Cmim][TfN]). The stability constants of TRDGA/Nd complexes (where R = n-pentyl, n-hexyl, n-octyl, n-decyl and 2-ethylhexl) were determined by absorbance spectroscopy. All the DGA ligands formed a 1 : 3 (Nd/DGA) complex as the limiting species. Solvent extraction data on Am and Eu were obtained with the TRDGA ligands in [Cmim][TfN] to arrive at a correlation between their extraction behaviour and complexation constant. The nature of the complex formed in the single phase titration (in [Cmim][TfN]) and those extracted in the [Cmim][TfN] medium from the aqueous phase were found to be identical. Fluorescence lifetime data confirmed that, in both single phase titration and biphasic solvent extraction, the complexation proceeded via replacement of water molecules from the primary coordination sphere of the metal ion. The spectroscopic data confirmed the absence of NO and TfN ions or HO in the extracted complexes.
本文报道了一系列四烷基二甘醇酰胺（TRDGA）与三价f阳离子在室温离子液体即3-辛基-1-甲基咪唑双（三氟甲磺酰）亚胺（[Cmim][TfN]）中的络合作用。通过吸光光谱法测定了TRDGA/Nd络合物（其中R = 正戊基、正己基、正辛基、正癸基和2-乙基己基）的稳定常数。所有的DGA配体均形成了1∶3（Nd/DGA）络合物作为极限物种。利用[Cmim][TfN]中的TRDGA配体获得了关于Am和Eu的溶剂萃取数据，以得出它们的萃取行为与络合常数之间的相关性。发现在单相滴定（在[Cmim][TfN]中）中形成的络合物以及在[Cmim][TfN]介质中从水相中萃取的络合物的性质是相同的。荧光寿命数据证实，在单相滴定和双相溶剂萃取中，络合作用都是通过取代金属离子一级配位层中的水分子来进行的。光谱数据证实，萃取的络合物中不存在NO和TfN离子或HO。
