Vilsmeier Complex Promotes Polycondensation of Imidodisulfuryl Chloride with Diols: Preparation of Ionic Oligomer Electrolytes

We report polycondensation of imidodisulfuryl chloride with diol monomers in the presence of catalysts. The method proceeds via stabilization of imidodisulfuryl chloride by the formation of a complex with N, N -dimethylformamide. This compound is well known as a Vilsmeier complex. The method is versatile and permits the incorporation of alkyl monomers in the oligomer backbone, and a maximum of 17 repeating units is reported. Linear ionic oligomers with protons, lithium ions, and BF4 – incorporated into the main chain are successfully produced to fabricate self-standing composite single-ion ionic membranes that exhibited good ionic conductivity and stability at high voltages. Pulsed-field gradient nuclear magnetic resonance (PFG NMR) has been utilized to investigate ion diffusion in membranes.