Open AccessColorimetric Cyanide Chemosensor Based on 1′,3,3′,4‐Tetrahydrospiro[chromene‐2,2′‐indole]
Author(s) -
Dagilienė Miglė,
Martynaitis Vytas,
Kriščiūnienė Vilija,
Krikštolaitytė Sonata,
Šačkus Algirdas
Publication year - 2015
Publication title -
chemistryopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 29
ISSN - 2191-1363
DOI - 10.1002/open.201402117
Subject(s) - cyanide , chemistry , indoline , indole test , sodium cyanide , acetonitrile , chromophore , photochemistry , adduct , nucleophilic aromatic substitution , combinatorial chemistry , nucleophilic substitution , inorganic chemistry , organic chemistry
A new class of chemosensors based on the 1′,3,3′,4‐tetrahydrospiro[chromene‐2,2′‐indole] ring system, which detects cyanide with high specificity, is described. These chemosensors show a distinct color change when treated with cyanide in acetonitrile solution buffered with sodium phosphate, and this procedure is not affected by the presence of other common anions. The chemisensors exhibit high sensitivity to low concentrations of cyanide, meeting the European Union water quality control criterion of sensitivity below 0.05 mg L −1 , and show a very fast response within tens of seconds. The mechanism for detection is rationalized by the nucleophilic substitution of the phenolic oxygen atom at the indoline C‐2 atom by the cyanide anion to form a stable indolylnitrile adduct and to generate the colored 4‐nitrophenolate chromophore. These chemosensors can be synthesized by a simple procedure from commercially available starting materials.