Malodorogenic Sensing of Carbon Monoxide

A thin film of poly-([IrCl(cod)(NHC-onbe)](n)-(propyl-onbe)(m)) (onbe=oxanorbornene) coated on filter paper reacts quantitatively with CO to yield 1,5-cyclooctadiene, the unpleasant smell of which can be detected by the human olfactory system with very high sensitivity. Odorless, but toxic CO is thus translated into the distinct smell of 1,5-cyclooctadiene. Based on malodorogenic sensing it is possible to smell the presence of CO.