Metal-directed synthesis of quadruple-stranded helical Eu(iii) molecular switch: a significant improvement in photocyclization quantum yield

Abstract

The self-assembly of a quadruple-stranded Eu(III) helicate induces the conformation transformation of a DAE-based photochromic ligand from parallel to antiparallel, which brings a significant improvement in the photocyclization quantum yield (Φ_o–c) as compared with the free ligand. Furthermore, the photocontrolled open- and closed-rings of the ligand realized a reversible modulation toward Eu³⁺ center emission.