Chalcone Based Colorimetric Sensor for Anions: Experimental and TD-DFT Study

The interactions between sensor chalcone of 3-(4-hydroxy-3-methoxyphenyl)-1-phenyl-2-propen-1-one (1) and anions (F–, Cl–, Br–, CN–, CO32–, and SO42–) have been experimentally and TD-DFT theoretically investigated. Sensor (1) showed a naked-eye detectable color change from yellow to red upon addition of F–, CO32–, CN–, and SO42– anions in DMSO, whereas no significant color change was observed upon addition of Cl– and Br– anions. The interaction models were predicted by optimizing (1)-anion complex using DFT/B3LYP method. Optimized (1)-anion complexes showed that sensor (1) was deprotonated by CO32–, CN–, F–, and SO42–. The formation of deprotonated sensor (1)– was responsible for the colorimetric signaling. Absorption spectra of neutral and deprotonated sensor were calculated using TD-DFT method. The calculated spectra were in good agreement with experimental results.

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ABSORPTION OF SOME SMALL SILVER CLUSTERS: DFT AND CASPT2 CALCULATIONS

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/55/6a/12367 ◽

2018 ◽

Vol 55 (6A) ◽

pp. 72

Author(s):

Ngo Tuan Cuong

Keyword(s):

Absorption Spectra ◽

Density Functional ◽

Noble Gas ◽

Silver Cluster ◽

Dft Method ◽

Basis Sets ◽

Silver Clusters ◽

Excitation Energies ◽

Complete Active Space ◽

Td Dft

Two quantum chemical methods which are the time-dependent density functional theory (TD-DFT) and the complete active space CASPT2/CASSCF have been used in modeling absorption spectra of silver clusters Agn (n = 2, 3, 4, 6, 8). There is an overall good agreement between TD-DFT and CASPT2 results for transition energies. The absorption spectra of the Agn clusters examined can reasonably be simulated using the excitation energies obtained by either TD-DFT or CASPT2 method. The main result emerged from this calculation is that the TD-DFT method is suitable for treatment of excited states of Ag clusters. The choice of specific functionals and basis sets to be used in some cases induces important effects on the calculated spectra. It is also noteworthy to mention that for some clusters, the neutral Ag6 for instance, the effect of noble gas environment is significant, while for some others such as the neutral Ag8, it is not. Therefore, carrying out TD-DFT calculations to reproduce and to assign a given structure to an experimental absorption spectrum of a silver cluster, it is not only to select suitable functionals but also to take enough effects of environments into account.

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Radiation Induced One-Electron Oxidation of 2-Thiouracil in Aqueous Solutions

Molecules ◽

10.3390/molecules24234402 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4402

Author(s):

Skotnicki ◽

Taras-Goslinska ◽

Janik ◽

Bobrowski

Keyword(s):

Absorption Band ◽

Absorption Spectra ◽

Sulfur Atom ◽

Density Functional ◽

Transient Absorption ◽

Dft Method ◽

Broad Absorption Band ◽

Transient Absorption Spectra ◽

Td Dft ◽

Type Radical

Oxidative damage to 2-thiouracil (2-TU) by hydroxyl (•OH) and azide (N3) radicals produces various primary reactive intermediates. Their optical absorption spectra and kinetic characteristics were studied by pulse radiolysis with UV-vis spectrophotometric and conductivity detection and by time-dependent density functional theory (TD-DFT) method. The transient absorption spectra recorded in the reactions of •OH with 2-TU depend on the concentration of 2-TU, however, only slightly on pH. At low concentrations, they are characterized by a broad absorption band with a weakly pronounced maxima located at λ = 325, 340 and 385 nm, whereas for high concentrations, they are dominated by an absorption band with λmax ≈ 425 nm. Based on calculations using TD-DFT method, the transient absorption spectra at low concentration of 2-TU were assigned to the ●OH-adducts to the double bond at C5 and C6 carbon atoms (3●, 4●) and 2c-3e bonded ●OH adduct to sulfur atom (1…●OH) and at high concentration of 2-TU also to the dimeric 2c-3e S-S-bonded radical in neutral form (2●). The dimeric radical (2●) is formed in the reaction of thiyl-type radical (6●) with 2-TU and both radicals are in an equilibrium with Keq = 4.2 × 103 M−1. Similar equilibrium (with Keq = 4.3 × 103 M−1) was found for pH above the pKa of 2-TU which involves admittedly the same radical (6●) but with the dimeric 2c-3e S-S bonded radical in anionic form (2●−). In turn, ●N3-induced oxidation of 2-TU occurs via radical cation with maximum spin location on the sulfur atom which subsequently undergoes deprotonation at N1 atom leading again to thiyl-type radical (6●). This radical is a direct precursor of dimeric radical (2●).

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Molecular structure, spectroscopic (UV-vis, FT-IR and FT- Raman), conformational aspects of 3t-pentyl-2r,6c-di(naphthalen-1-yl) piperidin-4-one oxime: a comprehensive experimental and DFT study

International Journal of Advanced Chemistry ◽

10.14419/ijac.v5i1.7186 ◽

2017 ◽

Vol 5 (1) ◽

pp. 8

Author(s):

K. Anandhy ◽

M. Arockia doss ◽

S. Amala ◽

S. Mahalakshmi ◽

G. Rajarajan

Keyword(s):

Molecular Structure ◽

Basis Set ◽

Geometrical Parameters ◽

Substitution Reactions ◽

B3lyp Method ◽

Visible Spectra ◽

Td Dft ◽

Ft Ir ◽

Good Agreement ◽

Ft Raman

The molecular structure and conformational aspects of 3t-pentyl-2r,6c-di(naphthalen-1-yl)piperidin-4-one oxime (3-PDNPO) were studied by using B3LYP level with 6-31G(d,p) p basis set. The optimized geometrical parameters are in agreement with analogue available single XRD data. The optimized parameters showed that the piperidin-4-one ring adopts chair conformation.The FT- IR and FT-Raman spectra were recorded within the region 4000-400 cm-1 and 4000-10 cm-1, respectively. It was found by experimental wavenumbers and DFT wavenumbers were in good agreement. Electronic properties are investigated using TD-DFT/B3LYP method using 6-31G (d,p) basis set and compared with experimental UV-visible spectra. Additionally, the ΔE gap investigated three phases follows the order of CHCl3 > gas > Methanol. The favourite sites for substitution reactions were evaluated by Mulliken and MEP analyses. From NLO analysis, it is found that the hyperpolarizability values are two times greater than the urea.Our proposed simulation procedure offers an alternative compound with which we can evaluate or design the best candidate NLO material.

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A new phenothiazine-based fluorescent probe for detection of hydrazine with naked-eye color change properties

Chemical Papers ◽

10.1007/s11696-021-01859-6 ◽

2021 ◽

Author(s):

Nian Rao ◽

Yi Le ◽

Dan Li ◽

Yan Zhang ◽

Qin Wang ◽

...

Keyword(s):

Fluorescent Probe ◽

Color Change ◽

Eye Color ◽

Naked Eye

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Spectral properties of coumarin derivatives in various environments

Open Chemistry ◽

10.2478/s11532-012-0185-0 ◽

2013 ◽

Vol 11 (4) ◽

pp. 492-501 ◽

Cited By ~ 1

Author(s):

Alzbeta Holubekova ◽

Pavel Mach ◽

Jan Urban

Keyword(s):

Gas Phase ◽

Absorption Spectra ◽

Spectral Properties ◽

Density Functional ◽

Water Solution ◽

Blue Shift ◽

Coumarin Derivatives ◽

Complex Environments ◽

Td Dft ◽

Solvent Environment

AbstractThe structural and spectral properties of coumarin derivatives in complex environments were investigated within the time-dependent density functional theory (TD DFT). Absorption spectra calculations were obtained at TD PBE0/6-31+G(d,p) level of theory for coumarin47 in the gas-phase and in various polar and non-polar organic solvents. The geometries of coumarins 6, 30, 47 and 522 in the gas phase and in inclusion complexes with the β-cyclodextrin (βCD) were determined by PM3 and DFT (HCTH/6-31G) calculations. Encapsulation of coumarin in βCD and associated changes in electronic structure produced either a red or blue shift in the absorption spectra of coumarins. A proposed cavity model for βCD-coumarin complex in water solution allowed identification of various contributions to the overall shift in the absorption spectra of coumarin upon complex formation in a solvent environment

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Furan and Thiophene Analogs of Phenanthrene A Theoretical Study of the Absorption Spectra of Benzodifurans, Benzodithiophenes and Thienobenzofurans

Zeitschrift für Naturforschung B ◽

10.1515/znb-1971-1209 ◽

1971 ◽

Vol 26 (12) ◽

pp. 1235-1240 ◽

Cited By ~ 9

Author(s):

L. Klasinc ◽

J. V. Knop

Keyword(s):

Absorption Spectra ◽

Theoretical Study ◽

Oscillator Strengths ◽

Electron Transitions ◽

Good Agreement ◽

Lcao Mo

The LCAO -MO -SCF -CI method was applied to benzo(1,2-b : 4,3-b′) -difuran and -dithiophene, benzo (2,1-b : 3,4-b′) -difuran and -dithiophene, benzo (1,2-b : 3,4-b′) -difuran and -dithiophene, thieno (2,3-e) benzofuran, thieno (3,2-e) benzofuran, thieno (3,2-g) benzofuran, thieno (2,3-g) benzofuran, benzofuran, benzothiophene and phenanthrene. The calculated π-electron transitions and their oscillator strengths are in good agreement with known absorption spectra. The resemblance of these spectra to the absorption spectra of phenanthrene and phenanthrolines is discussed.

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Quantum-Chemical Ab Initio Calculations on Inda- and Thallabenzene (C5H5In and C5H5Tl) and their Structural Isomers η5-C5H5In and η5-C5H5Tl

Australian Journal of Chemistry ◽

10.1071/ch17472 ◽

2018 ◽

Vol 71 (3) ◽

pp. 102

Author(s):

Emma Persoon ◽

Yuekui Wang ◽

Gerhard Raabe

Keyword(s):

Ab Initio ◽

Quantum Chemical ◽

Density Functional ◽

Single Point ◽

Normal Modes ◽

Dft Method ◽

Basis Sets ◽

Triplet States ◽

Structural Isomers ◽

Td Dft

Quantum-chemical ab initio, time-independent, as well as time-dependent density functional theory (TD-DFT) calculations were performed on the so far elusive heterocycles inda- and thallabenzene (C5H5In and C5H5Tl), employing several different methods (MP2, CISD, CCSD, CCSD(T), BD, BD(T), QCISD, QCISD(T), CASSCF, DFT/B3LYP), effective core potentials, and different basis sets. While calculations on the MP2 level predict the ground states of the title compounds to be singlets with the first triplet states between 13 and 15 kcal mol−1 higher in energy, single point calculations with the QCISD(T), CCSD(T), and BD(T) methods at CCSD-optimized structures result in energy differences between the singlet and the triplet states in the range between 0.3 and 2.1 kcal mol−1 in favour of the triplet states. According to a CASSCF(8,8) calculation the triplets are also more stable by about 2.5–2.9 kcal mol−1. Calculations were also performed for the C5v-symmetric η5 structural isomers (cyclopentadienylindium, CpIn, and cyclopentadienylthallium, CpTl, Cp = C5H5) of the title compounds. At the highest level of theory employed in this study, C5H5In is between 79 and 88 kcal mol−1 higher in energy than CpIn, while this energy difference is even larger for thallabenzene where C5H5Tl is energetically between 94 and 102 kcal mol−1 above CpTl. In addition we report on the UV/vis spectra calculated with a TD-DFT method as well as on the spectra of the normal modes of C5H5In and C5H5Tl. Both types of spectra might facilitate identification of the title compounds eventually formed in photolysis or pyrolysis experiments.

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Excited-states of a rhenium carbonyl diimine complex: solvation models, spin–orbit coupling, and vibrational sampling effects

Physical Chemistry Chemical Physics ◽

10.1039/c7cp05126c ◽

2017 ◽

Vol 19 (40) ◽

pp. 27240-27250 ◽

Cited By ~ 28

Author(s):

Sebastian Mai ◽

Hugo Gattuso ◽

Maria Fumanal ◽

Aurora Muñoz-Losa ◽

Antonio Monari ◽

...

Keyword(s):

Absorption Spectra ◽

Excited States ◽

Orbit Coupling ◽

Spin Orbit Coupling ◽

Spin Orbit ◽

Implicit Solvation ◽

Td Dft ◽

Rhenium Carbonyl ◽

Solvation Models ◽

P Absorption

Absorption spectra of [Re(CO)3(imidazole)(phenanthroline)]+ were computed using TD-DFT with QM/MM, frozen-density embedding, and implicit solvation models.

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Chromogenic naked-eye detection of copper ion and fluoride

RSC Advances ◽

10.1039/c5ra16301c ◽

2015 ◽

Vol 5 (105) ◽

pp. 86463-86472 ◽

Cited By ~ 18

Author(s):

Ye Won Choi ◽

Jae Jun Lee ◽

Ga Rim You ◽

Sun Young Lee ◽

Cheal Kim

Keyword(s):

Color Change ◽

Copper Ion ◽

Eye Detection ◽

Naked Eye ◽

Colorimetric Chemosensor ◽

Naked Eye Detection

Colorimetric chemosensor was reported for detection of Cu2+ and F−via the color change from colorless to yellow and to orange.

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Desing of optical chemosensors for detection of cyanide ions in water environments

Yugra State University Bulletin ◽

10.17816/byusu20190182-87 ◽

2019 ◽

Vol 15 (1) ◽

pp. 82-87

Author(s):

Alexandra Alexandrovna Kudrevatykh ◽

Lyubov Stepanovna Klimenko ◽

Timofey Petrovich Martyanov

Keyword(s):

Aqueous Medium ◽

Absorption Spectra ◽

Stability Constants ◽

Molecular Interactions ◽

Color Change ◽

Cyanide Ion ◽

Colorimetric Test ◽

Optical Chemosensors ◽

Aqueous Mixture ◽

The Stability

Molecular interactions with various anions in the form of tetrabutylammonium salts in DMSO and DMSO-aqueous mixture were studied spectrophotometrically. It turned out that the solutions of 1-hydroxy-2-acylaminoanthraquinones in DMSO, originally yellow, became dark purple with the addition of cyanide, fluoride, phosphate, and acetate ions. The addition of other salts did not cause changes in the absorption spectra. When switching to aqueous DMSO, a contrasting color change in the solution was observed only with the addition of the cyanide ion. The stability constants of the complexes and the metrological characteristics of the processes were determined. On the basis of 1hydroxy-2-benzoylaminoanthraquinone, colorimetric test strips were made and tested for the detection of CN-ions in an aqueous medium.

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