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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

Absorption (A) spectra 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) without (spectrum A) and with (spectrum B) NaCN (10 equiv).
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fig02: Absorption (A) spectra 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) without (spectrum A) and with (spectrum B) NaCN (10 equiv).

Mentions: Steady state absorbance spectra of compounds 8 a–h, measured for solutions in the acetonitrile/phosphate buffer, revealed absorption in the UV region of the electronic spectra (Table 1). However, when a sodium cyanide solution, buffered with sodium phosphate (pH 7.6), was added to the aforementioned solutions of compounds 8 a–h (0.1 mm of 8 a–h, 1 mm NaCN in the cell), a new absorption band was observed in the visible area at approximately 420 nm (Table 1, Figure 2).


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)

Absorption (A) spectra 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) without (spectrum A) and with (spectrum B) NaCN (10 equiv).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig02: Absorption (A) spectra 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) without (spectrum A) and with (spectrum B) NaCN (10 equiv).
Mentions: Steady state absorbance spectra of compounds 8 a–h, measured for solutions in the acetonitrile/phosphate buffer, revealed absorption in the UV region of the electronic spectra (Table 1). However, when a sodium cyanide solution, buffered with sodium phosphate (pH 7.6), was added to the aforementioned solutions of compounds 8 a–h (0.1 mm of 8 a–h, 1 mm NaCN in the cell), a new absorption band was observed in the visible area at approximately 420 nm (Table 1, Figure 2).

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