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

摘要

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 (Phi (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.