Ab initio and density functional force field studies on the IR spectra and structure of diazonium dicyanomethylide (diazodicyanomethane)

Georgieva, M. K.

doi:10.1016/j.molstruc.2003.11.023

Cited by 7 publications

(1 citation statement)

References 27 publications

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“…The FT-IR spectra (Figure 5C) explicitly indicate that the primary amine group bending vibration peak 38,39 at 1640 cm −1 in m-CDs disappeared and a new absorption peak was generated at 2260.4 cm −1 after adding NO 2 − (5 μM), which was attributed to the triple bond or the double bond accumulation stretching vibration peak. 40,41 These results strongly suggested that the fluorescence quenching of m-CDs is mainly due to amino groups participating in the reaction and conversion to other functional groups that results in energy transfer. Interestingly, after adding N-(1-naphthyl)ethylenediamine dihydrochloride to the reaction solution of m-CDs and NO 2 − , we observed that the mixed solution immediately changed from colorless to magenta, and the absorbance of the magenta dye was positive in proportion to the concentration of NO 2 − , as shown in the inset of Figure 5D.…”

Section: Acs Sensorsmentioning

confidence: 99%

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

et al. 2019

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In this work, we proposed a new method based on carbon dots (named m-CDs) for selective and efficient detection of nitrite (NO2 –), which was based on the interaction between the amine group of m-CDs and NO2 – via a diazo reaction that produced diazonium salts and induced the fluorescence quenching of m-CDs. The concentration of NO2 – shows a good linear relationship with a quenched fluorescence intensity from 0.063 to 2.0 μM (R 2 = 0.996) with a detection limit of 0.018 μM. In addition, a ratiometric fluorescence probe (m-CDs@[Ru(bpy)3]2+) was constructed via electrostatic interaction by introducing Ru(bpy)3Cl2·6H2O as an internal reference fluorescent reagent. Interestingly, a transition of the fluorescent color of the ratiometric probe from cyan to red could be visually observed upon increasing the concentration of NO2 –. Based on these findings, a ratiometric fluorescent-based portable agarose hydrogel test kit was fabricated and applied for on-spot assessment of NO2 – content within 10 min. As far as we know, this is the first ratiometric fluorescent sensor for visual detection of NO2 –. It has broad application prospects in environmental monitoring and food safety assessment.

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Section: Acs Sensorsmentioning

confidence: 99%

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

et al. 2019

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Computational and experimental studies on the IR spectra and structure of the simplest nitriles (C₁ and C₂), their anions, and radicals

Georgieva¹,

Velcheva²

2005

Int J of Quantum Chemistry

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ABSTRACT:The structure and infrared spectra of formonitrile (hydrogen cyanide) and acetonitrile, their anions, and radicals (45 species in all) have been studied by density functional theory (DFT) B3LYP 6-31ϩϩG(d,p) calculations. The results obtained have been compared with the literature and original experimental data. The zero-point vibrational energy (ZPVE)-corrected deprotonation energies of the studied (and other) nitriles correlate fairly well (R ϭ 0.94) with their pK a values, measured in dimethyl sulfoxide (DMSO). The theoretical cyano stretching frequencies C'N of the species studied have been found to correlate satisfactorily (R ϭ 0.97) with the experimental ones. The latter correlation can be used for a theoretical estimation of C'N of many nitriles, their anions, and radicals. The geometry parameters for the molecules, calculated by the same theoretical method, practically coincide with those determined experimentally in the gas state.

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Computational study of energies and structures of 2,4,6‐pyrimidinetrione and its anions

Daskalova

Binev

2005

Int J of Quantum Chemistry

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Energies and structures of 2,4,6-pyrimidinetrione, its anion, dianion, and trianion have been studied by means of ab initio and density functional computations. According to these studies, the most stable among the molecular tautomers is the triketo form, followed by the 6-hydroxy tautomer, in full agreement with earlier theoretical results and with experimental data on the tautomeric equilibrium. The deprotonation energy of 1345.24 kJ mol Ϫ1 calculated for 2,4,6-pyrimidinetrione, corresponds to a moderately strong COH acid, in accordance with its experimental pK a 1 ϭ 8.4 (solvent dimethylsulfoxide). The calculated structural changes, caused by the molecule 3 monoanion conversion, are in good agreement with those found experimentally. Energy and structural changes, worked by both anion 3 dianion and dianion 3 trianion conversions, have also been computed and discussed.

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Ab initio and density functional force field studies on the IR spectra and structure of diazonium dicyanomethylide (diazodicyanomethane)

Cited by 7 publications

References 27 publications

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

Computational and experimental studies on the IR spectra and structure of the simplest nitriles (C₁ and C₂), their anions, and radicals

Computational study of energies and structures of 2,4,6‐pyrimidinetrione and its anions

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Ab initio and density functional force field studies on the IR spectra and structure of diazonium dicyanomethylide (diazodicyanomethane)

Cited by 7 publications

References 27 publications

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

Computational and experimental studies on the IR spectra and structure of the simplest nitriles (C1 and C2), their anions, and radicals

Computational study of energies and structures of 2,4,6‐pyrimidinetrione and its anions

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Product

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Computational and experimental studies on the IR spectra and structure of the simplest nitriles (C₁ and C₂), their anions, and radicals