Pertechnetate anion, binding

The tren-based heteroditopic receptor 22, featuring a tripodal tetrahedral amide hydrogen-bond anion-recognition site in combination with benzo-15-crown-5 ether cation-binding moieties, has been found to cooperatively bind chloride, iodide, and perrhenate anions via co-bound crown ether-complexed sodium cations. It also can efficiently extract the radioactive sodium pertechnetate from simulated aqueous nuclear waste streams. The anion-binding affinity of 22 is considerably reduced in the absence of a co-bound cation <1999CC1253>... 

Multi-crown dendrimers (Fig. 3.7-12) were found to exhibit good solubihty in solvents of low polarity, making them attractive as extractants for separation processes. The combination of protonated tertiary amine groups as anion binding sites together with cation-active crown ether moieties represents an approach for the simultaneous binding of cations and anions. Extraction studies performed with sodium pertechnetate and mercury(II) chloride have shown that the guest molecules are mainly bound in the interior of the protonated polyamine skeleton [18]. 

The solid phases 98-100 (Scheme 2.45) with immobilized polyamine covalent capsules have been designed in [57] for binding, separation, and extraction of perrhenate and pertechnetate anions from their aqueous solutions. While the Amberlite CG50 derivative 100 was unsuitable for this purpose, the siUca-based sorbents 98 and 99 showed a promising performance. Their... 

Beer, P D., Hopkins, P K., McKinney, J. D., Cooperative halide, perrhenate anion-sodium cation binding and pertechnetate extraction and transport by a novel tripodal tris(amido benzo-15-crown-5) ligand. Chem. Commun. 1999, 1253-1254. 

Figure 52-3 Formation and secretion of thyroid hormone. Iodine transport into the gland is inhibited by anions such as thiocyanate (SCN ), perchlorate (C 0 ), and pertechnetate (TcO ). The oxidation and organic binding of iodide to thyroglobuiin are blocked by thioureas, sulfonamides, and high concentrations of iodide. (Modified from Berger S, Quinn JLThyroid function. ln Tietz NW, ed. Fundamentals of clinical chemistry, 2nd ed. Philadelphia WB Saunders Co, 1976 585.)...

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