A coumarin based fluorescent chemodosimeter for phosgene gas detection instantaneously in solution and the gas phase was written by Paul, Sima;Ghosh, Pritam;Roy, Partha. And the article was included in New Journal of Chemistry in 2020.Reference of 51473-74-6 This article mentions the following:
A coumarin based compound, 7-(diethylamino)-2-oxo-2H-chromene-3-carbaldehyde oxime (DCCO), was developed as a visual fluorescent chemodosimeter for selective detection of highly toxic phosgene gas. DCCO exhibits absorption bands at 330 nm and 425 nm. In the presence of phosgene, the absorbance at 330 nm increases and the peak at 425 nm is shifted to 420 nm with decreasing absorbance accompanying a color change from yellow to colorless. The fluorescence intensity of the probe at 483 nm is enhanced in the presence of phosgene (λex = 425 nm) but nerve agents and other acid chlorides including trisphosgene could not induce any significant enhancement of the fluorescence. DCCO on interaction with phosgene is converted to the corresponding nitrile derivative, 7-(diethylamino)-2-oxo-2H-chromene-3-carbonitrile (DCC). The quantum yield was increased 13 fold on conversion from DCCO to DCC. The fluorescence enhancement was explained by the ICT mechanism, which was supported by theor. calculations It exhibits a rapid response for naked eye detection of phosgene. DCCO was used for the detection of phosgene in solution and the gas phase. In the experiment, the researchers used many compounds, for example, 7-(Diethylamino)-2-oxo-2H-chromene-3-carbonitrile (cas: 51473-74-6Reference of 51473-74-6).
7-(Diethylamino)-2-oxo-2H-chromene-3-carbonitrile (cas: 51473-74-6) belongs to nitriles. Nitriles are polar, as indicated by high dipole moments. As liquids, they have high relative permittivities, often in the 30s. Nitriles are susceptible to hydrogenation over diverse metal catalysts. The reaction can afford either the primary amine (RCH2NH2) or the tertiary amine ((RCH2)3N), depending on conditions.Reference of 51473-74-6
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts