B–O Dynamic Covalent Bond-Enabled Polyphenol-Mediated Macroporous Resin Efficiently Separating Boron Isotopes

The separation of boron isotopes (¹⁰B/¹¹B) is challenging due to the much smaller relative mass difference between the ¹⁰B- and ¹¹B-bearing compounds. Herein, we report an efficient separation of ¹⁰B by polyphenol-mediated macroporous resin (BWT-MR). The phenolic hydroxyl groups of BWT-MR chelate with B of B(OH)₃ into tetrahedral sp³ hybridized B-phenolic hydroxyl complexes. Then the isotope exchange reaction between ¹⁰B of B(OH)₃ and ¹¹B in ¹¹B-phenolic hydroxyl complexes is facilitated for the breaking of the B-O dynamic covalent bond of ¹¹B-phenolic hydroxyl complexes and rebuilding of the B-O dynamic covalent bond of ¹⁰B-phenolic hydroxyl complexes, leading to the enrichment of ¹⁰B on BWT-MR. The corresponding single-stage separation factor is high up to 1.043. Moreover, the flow-through separation in the fixed bed enables experimental validation for practical industrial applications, achieving a high ¹⁰B abundance (21.64%). This work paves the way for the exploitation of more efficient enrichment of ¹⁰B for sustainable nuclear energy and biomedical research.