Lewis-Pairing-Induced Electrochemiluminescence Enhancement from Electron Donor-Acceptor Diads Decorated with Tris(pentafluorophenyl)borane as an Electrochemical Protector

This study reports an effective peripheral decoration of organic donor-acceptor diads with B(C₆F₅)₃ for stabilizing electrogenerated radical ions. By employing a common p-type organic semiconductor benzothienobenzothiophene (BTBT) as the donor, tetracoordinate boron complexes showed improved solution electrochemiluminescence (ECL) intensity, reaching a 156-fold increase compared to that of the parent diad. The unprecedented Lewis-pairing-induced ECL enhancement is attributed to the multiple roles of B(C₆F₅)₃: 1) redistributing frontier orbitals, 2) facilitating electrochemical excitation, and 3) restricting molecular motions. Furthermore, B(C₆F₅)₃ converted the molecular arrangement of BTBT from conventional 2D herringbones into 1D π-stacks. This robust, highly ordered columnar nanostructure allowed red-shifting of the crystalline film ECL with electrochemical doping through the electronic coupling pathways of BTBT. Our approach will facilitate the development of elaborate metal-free ECL systems.     

Impedance Effect on Ion Transport in a Temperature‐Sensitive Gel Membrane

The impedance effect on the ion transport of lithium chloride through temperature‐ and pH‐sensitive gel membranes was investigated. Both conductance and loss tangent show a relatively high value at temperatures near the lower critical solution temperature (14°C), followed by an abrupt drop with a further rise in temperature. The Figure shows an example of changes in absolute complex conductance (Y ), real conductance (G ), and imaginary conductance (B) for a poly(acryloyl‐L ‐proline methyl ester) gel membrane.