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Colorimetric Cyanide Chemosensor Based on 1',3,3',4-Tetrahydrospiro[chromene-2,2'-indole].

Dagilienė M, Martynaitis V, Kriščiūnienė V, Krikštolaitytė S, Šačkus A - ChemistryOpen (2015)

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Institute of Synthetic Chemistry, Kaunas University of Technology Radvilėnų pl. 19, 50254, Kaunas, Lithuania ; Department of Organic Chemistry, Kaunas University of Technology Radvilėnų pl. 19, 50254, Kaunas, Lithuania.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Formation of 1H-indole-2-carbonitrile 10. Reagents and conditions: a) THF, NaCN, H2O, rt, 1 h.
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sch05: Formation of 1H-indole-2-carbonitrile 10. Reagents and conditions: a) THF, NaCN, H2O, rt, 1 h.

Mentions: When compound 8 a was treated with sodium cyanide in tetrahydrofuran (THF) containing a small amount of water, the reaction afforded indole-2-carbonitrile 10 (Scheme 5), the structure of which was confirmed by spectroscopic methods and elemental analysis. The IR spectrum of 10 contains an absorption band at 2222 cm−1, characteristic for nitriles.30 The heteronuclear multiple bond coherence (HMBC) spectrum revealed three bonds range coupling between the methylidene protons at 2.15 and 2.30 ppm and the nitrile carbon at 118.49 ppm.31,32 These protons also interact with the quaternary carbon at 76.75 ppm, separated by two bonds, and with the quaternary carbons at 46.76 and 128.16 ppm, separated by three bonds. The full assignments presented in Figure 3 were based on the combined application of standard NMR techniques such as COSY, NOESY, ROESY, APT, DEPT, HSQC and HMBC spectra.


Colorimetric Cyanide Chemosensor Based on 1',3,3',4-Tetrahydrospiro[chromene-2,2'-indole].

Dagilienė M, Martynaitis V, Kriščiūnienė V, Krikštolaitytė S, Šačkus A - ChemistryOpen (2015)

Formation of 1H-indole-2-carbonitrile 10. Reagents and conditions: a) THF, NaCN, H2O, rt, 1 h.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4522186&req=5

sch05: Formation of 1H-indole-2-carbonitrile 10. Reagents and conditions: a) THF, NaCN, H2O, rt, 1 h.
Mentions: When compound 8 a was treated with sodium cyanide in tetrahydrofuran (THF) containing a small amount of water, the reaction afforded indole-2-carbonitrile 10 (Scheme 5), the structure of which was confirmed by spectroscopic methods and elemental analysis. The IR spectrum of 10 contains an absorption band at 2222 cm−1, characteristic for nitriles.30 The heteronuclear multiple bond coherence (HMBC) spectrum revealed three bonds range coupling between the methylidene protons at 2.15 and 2.30 ppm and the nitrile carbon at 118.49 ppm.31,32 These protons also interact with the quaternary carbon at 76.75 ppm, separated by two bonds, and with the quaternary carbons at 46.76 and 128.16 ppm, separated by three bonds. The full assignments presented in Figure 3 were based on the combined application of standard NMR techniques such as COSY, NOESY, ROESY, APT, DEPT, HSQC and HMBC spectra.

Bottom Line: 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 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.

View Article: PubMed Central - PubMed

Affiliation: Institute of Synthetic Chemistry, Kaunas University of Technology Radvilėnų pl. 19, 50254, Kaunas, Lithuania ; Department of Organic Chemistry, Kaunas University of Technology Radvilėnų pl. 19, 50254, Kaunas, Lithuania.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus