Sensor material based on occluded trisulfur anionic radicals for convenient detection of trace amounts of water molecules

Abstract

Trisulfur anionic radicals, which are chromogenic, have been generated through reaction of vaporized sulfur with univalent zinc in a microporous silicoaluminophosphate. It was found that these radicals are accessible to guest molecules and respond uniquely to water molecules, and as a result the radical-containing composite material functions as an efficient detector for trace amounts of H₂O both in air and in organic solvents. A simple system that employs this unique composite material is fabricated to detect parts per million levels of water in organic media on the basis of color variation.