A real-time colorimetric and ratiometric fluorescent probe for sulfite was written by Wu, Ming-Yu;He, Ting;Li, Kun;Wu, Ming-Bo;Huang, Zheng;Yu, Xiao-Qi. And the article was included in Analyst (Cambridge, United Kingdom) in 2013.Category: nitriles-buliding-blocks This article mentions the following:
A real-time colorimetric and ratiometric fluorescent probe based on modulating the intramol. charge transfer (ICT) of the coumarin platform for selective detection of sulfite is presented. This reaction based probe used the Michael addition to the dicyano-vinyl group with the detection limit of 5.8 × 10-5 M The probe displayed a high selectivity for sulfite over other anions and reactive sulfur especially for biothiols including cysteine (Cys), homocysteine (Hcy) and glutathione (GSH), with ∼100 nm blue shift and >230 times intensity ratios change of the emission spectrum. Meanwhile, it could be easily observed that the probe for sulfite changes from red to pale yellow by the naked eye, and from red to blue under UV lamp immediately after the sulfite is added. It is the fastest response probe for sulfite ever reported, which could give a colorimetric and ratiometric fluorescent response instantly. In the experiment, the researchers used many compounds, for example, 7-(Diethylamino)-2-oxo-2H-chromene-3-carbonitrile (cas: 51473-74-6Category: nitriles-buliding-blocks).
7-(Diethylamino)-2-oxo-2H-chromene-3-carbonitrile (cas: 51473-74-6) belongs to nitriles. The R-C-N bond angle in and nitrile is 180° which give a nitrile functional group a linear shape. Both the carbon and the nitrogen are sp hydridized which leaves them both with two p orbitals which overlap to form the two π bond in the triple bond. Asymmetric bioreduction of nitriles is an attractive route to produce optically active nitriles as current metal-catalyzed hydrogenations tend to have low reactivity.Category: nitriles-buliding-blocks
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts