Ultrafast and selective separation of 99mTc from molybdenum matrix using DBDGA deliberately tailored macrocyclic crown-ethers.

Technetium-99m (99mTc) is an important medical radionuclide. Due to the crisis in supply of molybdenum-99 (99Mo), production of 99mTc directly via the 100Mo (p, 2 n) reaction by cyclotron was proposed. In this process, the most critical challenge is to rapidly and efficiently separate 99mTc from high concentration of molybdenum. In this work, a novel ligand, bis(N,N -dibutyldiglycolamide)dibenzo-18-crown-6 (BisDBDGA-DB18C6) was successfully synthesized and used for extraction of TcO 4 - /ReO 4 - from molybdenum. The results demonstrated that BisDBDGA-DB18C6 expressed excellent selectivity for TcO 4 - with a high separation factor of 1.6 × 105 against Mo, a fast extraction kinetic (within 45 s), and a high extraction capacity of 211 mmol ReO 4 - (99TcO 4 -)/per mole of extractant. The extraction mechanism was proposed as a co-interaction of macrocyclic crown ether and N,N -dibutyldiglycolamide group through slope analysis, FT-IR, ESI-MS, 1H NMR titration and theory calculations. Importantly, 99Tc in the organic phase can be quantitatively (> 99%) and easily back-extracted using deionized water, which can be directly used for medical applications. [Display omitted] • A novel ligand BisDBDGA-DB18C6 was first prepared. • The tailored BisDBDGA-DB18C6 exhibits ultrafast extraction kinetic (within 45 s). • Superior extraction performance toward Tc/Re over Mo is confirmed and evaluated. • The solution is stripped with deionized water for direct medical applications. [ABSTRACT FROM AUTHOR]