Synthesis and Characterization of a Helicene-Based Imidazolium Salt and Its Application in Organic Molecular Electronics

Herein we demonstrate the synthesis of a helicene‐based imidazolium salt. The salt was prepared by starting from racemic 2‐methyl[6]helicene, which undergoes radical bromination to yield 2‐(bromomethyl)[6]helicene. Subsequent treatment with 1‐butylimidazole leads to the corresponding salt 1‐butyl‐3‐(2‐methyl[6]helicenyl)‐imidazolium bromide. The prepared salt was subsequently characterized by using NMR spectroscopy and X‐ray analysis, various optical spectrometric techniques, and computational chemistry tools. Finally, the imidazolium salt was immobilized onto a SiO2 substrate as a crystalline or amorphous deposit. The deposited layers were used for the development of organic molecular semiconductor devices and the construction of a fully reversible humidity sensor. Humidity sensors: A helicene‐based imidazolium salt was prepared and characterized by NMR spectroscopy and X‐ray analysis, various optical spectrometric techniques, and computational chemistry tools. The salt was then immobilized onto a SiO2 substrate as a crystalline or amorphous deposit (see figure) and the deposited layers used for the development of organic molecular semiconductor devices and the construction of a fully reversible humidity sensor.