scholarly journals Novel acridine-based thiosemicarbazones as ‘turn-on' chemosensors for selective recognition of fluoride anion: a spectroscopic and theoretical study

2018 ◽  
Vol 5 (7) ◽  
pp. 180646 ◽  
Author(s):  
Ibanga Okon Isaac ◽  
Iqra Munir ◽  
Mariya al-Rashida ◽  
Syed Abid Ali ◽  
Zahid Shafiq ◽  
...  
Keyword(s):  
Density Functional ◽  
Theoretical Study ◽  
Fluoride Anion ◽  
Metal Fluoride ◽  
Visible Absorption ◽  
Functional Theory ◽  
H Nmr ◽  
Tetrabutylammonium Fluoride ◽  
Uv Visible ◽  
Nickel Fluoride

New thiosemicarbazide-linked acridines 3a–c were prepared and investigated as chemosensors for the detection of biologically and environmentally important anions. The compounds 3a–c were found selective for fluoride (F − ) with no affinity for other anions, i.e. − OAc, Br − , I − , HSO 4 − , SO 4 2− , PO 4 3− , ClO 3 − , ClO 4 − , CN − and SCN − . Further, upon the gradual addition of a fluoride anion (F − ) source (tetrabutylammonium fluoride), a well-defined change in colour of the solution of probes 3a–c was observed. The anion-sensing process was studied in detail via UV–visible absorption, fluorescence and 1 H-NMR experiments. Moreover, during the synthesis of acridine probes 3a–c nickel fluoride (NiF 2 ), a rarely explored transition metal fluoride salt, was used as the catalyst. Theoretical studies via density functional theory were also carried out to further investigate the sensing and anion (F − ) selectivity pattern of these probes.

Role of heteroatoms and substituents on the structure, reactivity, aromaticity, and absorption spectra of pyrene: a density functional theory study

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Bapan Saha ◽  
Pradip Kumar Bhattacharyya
Keyword(s):  
Density Functional Theory ◽  
Absorption Spectra ◽  
Density Functional ◽  
Structural Parameters ◽  
Visible Absorption ◽  
Functional Theory ◽  
Solvent Phase ◽  
Visible Spectra ◽  
Td Dft ◽  
Uv Visible

Abstract Effect of heteroatoms viz. BN and substituents viz. –Me (methyl), –OH (hydroxyl), –NH2 (amine), –COOH (carboxyl), and –CN (cyano) on the structural parameters, global reactivity, aromaticity, and UV-visible spectra of pyrene are studied with the help of density functional theory (DFT). Global reactivity parameters such as global hardness (η) and electrophilicity (ω) are calculated using density functional reactivity theory (DFRT). Time dependent density functional theory (TD-DFT) is explored for interpreting the UV-visible absorption spectra. Aromaticity of the pyrene rings are predicted from the nucleus independent chemical shift (NICS) values. Presence of BN unit and substituent induces reasonable impact on the studied parameters. The observed absorption spectra lie predominantly within the UV-region (both blue and red shifts are observed in presence of BN and substituent). HOMO energy and absorption spectra are affected nominally in solvent phase.

Experimental and Theoretical Study on the Interaction of P-Aminophenol Hydrochloride with H2O

2019 ◽  
Vol 233 (2) ◽  
pp. 303-313 ◽  
Author(s):  
Bingbing Hou ◽  
Peng Peng ◽  
Ping Zhang ◽  
Cuiping Zhai
Keyword(s):  
Hydrogen Bonds ◽  
Density Functional ◽  
Nmr Spectra ◽  
Theoretical Study ◽  
Cathodic Peak ◽  
Absorption Bands ◽  
Functional Theory ◽  
H Nmr ◽  
Hydrogen Bond Interactions ◽  
Atoms In Molecules Theory

Abstract UV-Vis absorption spectra, cyclic voltammetry and 1H nuclear magnetic resonance (1H NMR) spectra were applied to explore the hydrogen bond interactions of p-aminophenol hydrochloride (PAH) with H2O. The results indicated the hydrogen bonds were formed in PAH–H2O system. The anodic/cathodic peak potentials and UV-Vis absorption bands of PAH in H2O could be affected due to the interactions. The results of density functional theory, atoms in molecules theory and natural bond orbital analyses further confirmed the existence of hydrogen bonds between the phenolic hydroxyl, –NH3+ protons and Cl− of PAH and H2O. Furthermore, the π-π stacking was suggested between PAH benzene rings from the 1H NMR spectra at higher concentrations.

scholarly journals A new fluorescent chemosensor for fluoride anion based on a pyrrole–isoxazole derivative

2011 ◽  
Vol 7 ◽  
pp. 46-52 ◽  
Author(s):  
Zhipei Yang ◽  
Kai Zhang ◽  
Fangbin Gong ◽  
Shayu Li ◽  
Jun Chen ◽  
...  
Keyword(s):  
Density Functional ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Fluoride Anion ◽  
Fluorescence Emission Spectra ◽  
Functional Theory ◽  
Binding Motifs ◽  
H Nmr ◽  
Isoxazole Derivative ◽  
Fluoride Detection

Molecules containing polarized NH fragments that behave as anion-binding motifs are widely used as receptors for recognition and sensing purposes in aprotic solvents. We present here a new example of a receptor, 3-amino-5-(4,5,6,7-tetrahydro-1H-indol-2-yl)isoxazole-4-carboxamide (receptor 1), which contains pyrrole, amide and amino subunits. This receptor shows both changes in its UV–vis absorption and fluorescence emission spectra upon the addition of F−, resulting in highly selectivity for fluoride detection over other anions, such as Cl−, Br−, I−, HSO4 −, H2PO4 − and AcO− in CH3CN. 1H NMR titration, time-dependent density functional theory (TDDFT) calculations and other experiments confirm that the sensing process is brought about by deprotonation of the pyrrole-NH in receptor 1.

scholarly journals Molecular Structures and Spectral Properties of Natural Indigo and Indirubin: Experimental and DFT Studies

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3831 ◽  
Author(s):  
Zixin Ju ◽  
Jie Sun ◽  
Yanping Liu
Keyword(s):  
Density Functional Theory ◽  
Spectral Properties ◽  
Density Functional ◽  
Dft Method ◽  
Molecular Structures ◽  
Basis Set ◽  
Frontier Molecular Orbital ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible

This paper presents a comparative study on natural indigo and indirubin in terms of molecular structures and spectral properties by using both computational and experimental methods. The spectral properties were analyzed with Fourier transform infrared (FTIR), Raman, UV-Visible, and fluorescence techniques. The density functional theory (DFT) method with B3LYP using 6-311G(d,p) basis set was utilized to obtain their optimized geometric structures and calculate the molecular electrostatic potential, frontier molecular orbitals, FTIR, and Raman spectra. The single-excitation configuration interaction (CIS), time-dependent density functional theory (TD-DFT), and polarization continuum model (PCM) were used to optimize the excited state structure and calculate the UV-Visible absorption and fluorescence spectra of the two molecules at B3LYP/6-311G(d,p) level. The results showed that all computational spectra agreed well with the experimental results. It was found that the same vibrational mode presents a lower frequency in indigo than that in indirubin. The frontier molecular orbital analysis demonstrated that the UV-Visible absorption and fluorescence bands of indigo and indirubin are mainly derived from π → π* transition. The results also implied that the indigo molecule is more conjugated and planar than indirubin, thereby exhibiting a longer maximum absorption wavelength and stronger fluorescence peak.

scholarly journals Theoretical Study of the Absorption Spectrum and the Thermochemistry of the CF3OSO3 Radical

2010 ◽  
Vol 65 (8-9) ◽  
pp. 720-724 ◽  
Author(s):  
Carlos J. Cobos ◽  
Adela E. Croce
Keyword(s):  
Absorption Spectrum ◽  
Density Functional ◽  
Basis Set ◽  
Absorption Bands ◽  
Visible Absorption ◽  
Functional Theory ◽  
Dissociation Enthalpy ◽  
The Density Functional Theory ◽  
Uv Visible ◽  
Experimental Absorption

The UV-visible absorption spectrum of the recently reported CF3OSO3 radical has been studied by using the time-dependent generalization of the density functional theory (TDDFT). For this a set of eleven hybrid functionals combined with the 6-311+G(3df) basis set were employed. The main features of the three experimental absorption bands of CF3OSO3 recorded over the 220 - 530 nm range are well reproduced by the calculations. A dissociation enthalpy for the CF3O-SO3 bond of 19.1 kcal mol−1 is predicted at the BAC-G3MP2//B3LYP/6-311+G(3df) level of theory

scholarly journals 2,4-Bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridines: synthesis and photophysical properties

2021 ◽  
Vol 17 ◽  
pp. 1629-1640
Author(s):  
Najeh Tka ◽  
Mohamed Adnene Hadj Ayed ◽  
Mourad Ben Braiek ◽  
Mahjoub Jabli ◽  
Noureddine Chaaben ◽  
...  
Keyword(s):  
Density Functional ◽  
Photophysical Properties ◽  
Chemical Properties ◽  
Efficient Synthesis ◽  
One Pot ◽  
Visible Absorption ◽  
Functional Theory ◽  
Uv Visible ◽  
Physical And Chemical ◽  
And Chemical Properties

Acridine derivatives have attracted considerable interest in numerous areas owing to their attractive physical and chemical properties. Herein, starting from readily available anthranilic acid, an efficient synthesis of 2,4-bis(arylethynyl)-9-chloro-5,6,7,8-tetrahydroacridine derivatives was accomplished via a one-pot double Sonogashira cross-coupling method. The UV-visible absorption and emission properties of the synthesized molecules have been examined. Additionally, theoretical studies based on density functional theory (DFT/B3LYP/6-31G(d)) were carried out.

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