Sensing Hg²⁺ with a Core-Modified Expanded Porphyrine

Significance

Extended porphyrins possess interesting optical and coordination properties which can be exploited in molecular recognition and sensing. The authors have synthesized the core-modified rubyrin 4 starting from thiophene whose soft-donor sites enable a particularly good interaction with Hg²⁺ ions. The compound was then incorporated into a polyurethane hydrogel and used as a mercury sensor in aqueous media.