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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

Absorbance at 422 nm of 8 a (0.1 mm, 298 K) in a mixture of CH3CN/phosphate buffer (Na2HPO4/NaH2PO4, 7.5 mm, pH 7.6) (19:1 v/v) in the presence of CN− or other common anions (10 equiv) or ion mixtures (10 equiv of CN−, HSO4−, Cl−, Br−, and F−); A0 is the absorbance of 8 a at 422 nm in the absence of CN−.
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fig06: Absorbance at 422 nm of 8 a (0.1 mm, 298 K) in a mixture of CH3CN/phosphate buffer (Na2HPO4/NaH2PO4, 7.5 mm, pH 7.6) (19:1 v/v) in the presence of CN− or other common anions (10 equiv) or ion mixtures (10 equiv of CN−, HSO4−, Cl−, Br−, and F−); A0 is the absorbance of 8 a at 422 nm in the absence of CN−.

Mentions: To test the selectivity of chemosensor 8 a, parallel investigations were carried out with a series of other anions (F−, Cl−, Br−, I−, CH3COO−, C2O42−, HCO3−, HSO3−, HSO4−, NO2−, NO3−, SCN−, SO32−, SO42−, S2O32−). The addition of excess amounts of these anions did not result in significant absorbance spectral changes during UV/vis titration (Figure 6), indicating that this potential chemosensor demonstrates excellent selectivity for cyanide over other common anions. The high selectivity of chemosensing can be explained by the fact that only the addition of a cyanide anion on the indoline nucleus forms a strong enough covalent bond with the indole C-2 atom to afford stable nitrile 9, while the addition of the other aforementioned anions is a reversible process.


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)

Absorbance at 422 nm of 8 a (0.1 mm, 298 K) in a mixture of CH3CN/phosphate buffer (Na2HPO4/NaH2PO4, 7.5 mm, pH 7.6) (19:1 v/v) in the presence of CN− or other common anions (10 equiv) or ion mixtures (10 equiv of CN−, HSO4−, Cl−, Br−, and F−); A0 is the absorbance of 8 a at 422 nm in the absence of CN−.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig06: Absorbance at 422 nm of 8 a (0.1 mm, 298 K) in a mixture of CH3CN/phosphate buffer (Na2HPO4/NaH2PO4, 7.5 mm, pH 7.6) (19:1 v/v) in the presence of CN− or other common anions (10 equiv) or ion mixtures (10 equiv of CN−, HSO4−, Cl−, Br−, and F−); A0 is the absorbance of 8 a at 422 nm in the absence of CN−.
Mentions: To test the selectivity of chemosensor 8 a, parallel investigations were carried out with a series of other anions (F−, Cl−, Br−, I−, CH3COO−, C2O42−, HCO3−, HSO3−, HSO4−, NO2−, NO3−, SCN−, SO32−, SO42−, S2O32−). The addition of excess amounts of these anions did not result in significant absorbance spectral changes during UV/vis titration (Figure 6), indicating that this potential chemosensor demonstrates excellent selectivity for cyanide over other common anions. The high selectivity of chemosensing can be explained by the fact that only the addition of a cyanide anion on the indoline nucleus forms a strong enough covalent bond with the indole C-2 atom to afford stable nitrile 9, while the addition of the other aforementioned anions is a reversible process.

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