Imidazole-coumarin containing D – A type fluorescent probe: Synthesis photophysical properties and sensing behavior for F− and CN− anion (original) (raw)
Related papers
Optical Materials, 2018
Highly fluorescence, 3-(p-nitrophenyl)-7-diethylamino and 3-cyano-7-diethylaminocoumarin, iminocoumarins derivatives differing by the position of substituents and acceptors groups were investigated and characterized using 1 H, 13 C NMR and FT-IR spectroscopy analysis. These dyes were photophysically characterized and the effects of the substituents investigated. As a result, efficient charge transfer was maintained through the molecule. UV-visible absorption and fluorescence spectra of these dyes became shifted to longer wavelengths upon substitution at 7-position and depend on the attractor group. However, tradeoffs in spectral shifts were observed when two donor attractor electron groups such as N-diethyl substitue at position 7 and nitrophenyl in position 3, respectively. Theoretical calculations were performed using density functional theory (DFT) for studying the molecular structure and optical properties of the investigated molecule.
Comptes Rendus Chimie, 2006
The optical properties of two new iminocoumarin dyes, bearing a cyano group at the 3-position and an N-diethylamino group at the 7-position, were studied by UV-vis absorption and fluorescence spectroscopy in a large number of solvents. Dye 1 bears a free imino group, while dye 2 is substituted by an ethoxycarbonyl group on the imino function. The properties of these dyes were compared with those of 3-cyano-7-diethylaminocoumarin (3). The study shows that the three compounds display close spectroscopic behaviour in a large range of solvents, but the iminocoumarins exhibit much better fluorescence efficiency than the coumarin in polar and moderately protic solvents. This shows that iminocoumarin derivatives can advantageously replace coumarins in this type of solvents, and confirms that substitution on the imino group is a convenient way to obtain good fluorescent probes designed for various purposes. To cite this article: H. Turki et al., C. R. Chimie 9 (2006).
Dual Fluorescence and Solvatochromic Study on 3-Acyl Coumarins
Journal of Fluorescence, 2017
Electronic absorption and emission spectra of 3acetyl coumarin, 3-(bromoacetyl) coumarin and 3-(di bromoacetyl) coumarin have been recorded at room temperature in thirteen solvents with different polarities. Both ground and excited state dipole moments have been calculated for both locally excited and charge transfer transitions by using the solvatochromic method. Excited state dipole moments of all the three compounds are higher than their ground state values. DFT calculations have been profound to estimate their ground and excited state dipole moments. The estimated change in dipole moment by the application of microscopic solvent polarity parameter and bulk solvent polarity methods are in close agreement. Concentration dependent dual fluorescence has been observed in the emission spectra of all the three compounds.
A Novel Coumarin Fluorescent Sensor to Probe Polarity Around Biomolecules
Journal of Biomedical Nanotechnology, 2009
Polarity-sensitive (solvatochromic) probes are useful tools to investigate on subtle biochemical processes which occur at membrane and subcellular level (e.g., the uptake and cell targeting of a functionalized nanoparticle). In this paper, we describe the development of a new solvatochromic biosensor. The probe is structured as a "push-pull" system, bearing an electron-rich naphtyl ring and an electron poor benzothiazene group, conjugated to a central coumarin core. These features confer interesting spectroscopic and solvatochromic properties to the fluorophore. The dye was derivatized with a versatile sulfonyl chloride functional group. We also demonstrated that solvatochromic properties are nearly maintained when the fluorophore is covalently linked to proteins usually employed for nanoparticle coatings (bovine serum albumin or streptavidin). Finally, we proved the efficiency of our polarity-sensitive probe by obtaining a statistically significant difference between the fluorescence signals of fluorophore-labeled streptavidin before and after addition of BSA-labeled biotin.
Available online xxxx (S)-4-((4-((3-amino-2-oxo-4-phenylbutoxy)methyl)-1H-1,2,3-triazol-1-yl)methyl)-7 hydroxy-2H-chromen-2one hydrochloride was synthesized and characterized by detailed spectroscopic studies such as 1 H, 13 C NMR and HRMS. Excited state dipole moment of synthesized compound was obtained using different solvatochromic shift methods. High value of dipole moment is observed for excited state as compared to ground state value and this is attributed to more polar excited state of molecule. Also, fluorescence emission peak undergoes a bathochromic shift with increase in the polarity of the solvent, confirming π → π* transition. The potential sensor behavior of the compound to metal ions has also been examined. Chemosensor shows the sensitivity for Fe 3+ and Cu 2+ over other metal cations in aqueous solution. The detection limits of Fe 3+ and Cu 2+ were calculated to be 143 nM and 71.31 μM, respectively. The LC-mass analysis indicated that 1:1 complex was formed between Fe 3+ (or) Cu 2+ and compound. Binding energy values for the complexation of the compound with metal ions are theoretically computed at M06/6-31 + G(d,p) level. The DFT based binding energy values show good correlation with the experimental observations.
Colorimetric and fluorescence sensing of anions using thiourea based coumarin receptors
Tetrahedron letters, 2006
Thiourea-containing coumarins 1, 2 have been designed and synthesized via reaction of 6-aminomethylcoumarin and the corresponding isothiocyanates. Their anion-binding ability has been examined using UV-vis, fluorescence and 1 H NMR. The anion recognition takes place through charge neutral thiourea receptor sites with concomitant fluorescence quenching of the coumarin moiety with 1 showing a strong binding to C 6 H 5 COO À over F À with a distinct change in color.
Journal of Molecular Structure, 2010
The X-ray diffraction (XRD) studies of a coumarin based hydrazone (receptor 1) have revealed self assembled pseudo double helix architecture involving closed shell O-O interactions besides other supramolecular interactions. The receptor (1) an intramolecular charge transfer (ICT) probe detected acetate, benzoate and dihydrogenphosphate through naked-eye in DMSO. The 1:1 stoichiometry was confirmed for all the anions. The 1 H NMR studies indicated classical and non-classical hydrogen bonding through -NH and Ar-H protons of the receptor, respectively, during recognition process of the acetate through receptor (1). The theoretical studies through density functional theory (DFT) using B3LYP exchange functional with the basis set 6-311G** supported the UV-vis and 1 H NMR studies. The time dependent density functional theory (TDDFT) computations of UV-vis excitations for the receptor (1) and receptor-acetate complex agreed well with our experimental findings. The cyclic voltammetric studies also supported formation of receptor-acetate complex.
Optical properties of new fluorescent iminocoumarins: Part 1
Dyes and Pigments, 2007
The optical properties of 10 new iminocoumarin dyes, bearing a cyano group at the 3-position, were studied in CH 2 Cl 2 by UV/vis absorption and fluorescence spectroscopy. Five of the dyes bear a free imino group, and differ by the nature and position of their electron-donor group. Among them, the dye bearing a diethylamino group at the 7-position displayed the most interesting optical properties. All the compounds were compared to analogues containing an ethoxycarbonyl group on the imino function. The presence of the ethoxycarbonyl group systematically induced a shift of the absorption and emission spectra towards long wavelengths. For the three dyes where charge transfer is weak, substitution reduced fluorescence efficiency. In contrast, the fluorescence quantum yield and lifetime were slightly increased for the compounds with strong charge transfer, and especially for that bearing a diethylamino group at the 7-position. This shows that substitution on the imino group can be a convenient way to obtain good fluorescent probes designed for various purposes.