Solvatochromic study of 3-N-(N′-methylacetamidino)benzanthrone and its interaction with dopamine by the fluorescence quenching mechanism

Development of a push-π-pull phenothiazine-vinyl-isophorone fluorophore: a novel solvatochromic and pH indicator

Knoevenagel condensation of phenothiazine-3,7-dicarbaldehyde with an isophorone yielded a new phenothiazine derivative (PTZ-c) fluorophore. The solvatochromic and pH-sensing abilities of PTZ-c, an asymmetric fluorophore with a single isophorone molecule, were shown to be exceptional. PTZ-c produced very delicate absorbance and emission spectra. When the polarity of the solvent was increased, the PTZ-c emission spectra showed greater sensitivity than the absorption spectra. Multiple spectroscopic techniques, including Fourier transform infrared spectroscopy, nuclear magnetic resonance, and mass spectrometry, were used to characterize the manufactured PTZ-c sensor. To demonstrate the beneficial solvatochromic behaviour associated with intramolecular charge transfer, the absorption spectra of the synthesized DA PTZ-c dye were analyzed in different solvents of varying polarity. Band intensity and the wavelength of PTZ-c emission were also found to be highly solvent dependent. It was observed that when solvent polarity was increased to a maximum of 4122 cm^-1 , Stokes' shift also increased. To analyze the Stokes' shift that depended on the solvent, a linear correlation between solvation and energy was used. An investigation of PTZ-c quantum yield (ф) was also conducted. Both the absorbance and fluorescence spectra of the sensor in dimethylformamide as a function of pH were studied. A fluorescence peak was seen at 562 nm, whereas the greatest absorption wavelengths were found at 403 and 317 nm. It was shown that the pH-sensing mechanism depended on protons removed from the PTZ-c chromophore, which caused a colour shift and variation in both emission and colorimetric properties.

A New Bioactive Complex between Zn(II) and a Fluorescent Symmetrical Benzanthrone Tripod for an Antibacterial Textile

A new fluorescent Zn(II) complex of symmetrical tripod form based on a 3-substituted benzanthrone (BT) has been synthesized and characterised. The basic photophysical properties of the new metal complex have been determined. It has been found by fluorescence spectroscopy that, one zinc ion forms a complex with the tripod ligand. The surface morphology of the ligand and its Zn(II) complex has been investigated by the scanning electron microscopy (SEM) technique. X-ray photoelectron spectroscopy (XPS) has been used for the characterisation of the chemical composition of the complex surfaces. The antibacterial activity of the Zn(II) complex has been investigated in solution and upon its deposition onto a cotton fabric. A reduction of biofilm formation on the surface of the cotton fabric has been observed compared to the non-treated cotton material. The results obtained demonstrate that the studied Zn(II) complex possesses good antimicrobial activity being most effective against the used Gram-positive bacteria.

Novel dye for detection of callus embryo by confocal laser scanning fluorescence microscopy

In the present study a new luminescent dye 3-N-(2-pyrrolidinylacetamido)benzanthrone (AZR) was synthesized. Spectroscopic measurements of the novel benzanthrone 3-aminoderivative were performed in seven organic solvents showing strong fluorescence. The capability of the prepared dye for visualization has been tested on flax, red clover and alfalfa to determinate the embryo in plant callus tissue cultures. Callus cells were stained with AZR and further analysed utilizing confocal laser scanning fluorescence microscopy. Performed experiments show high visualization effectiveness of newly synthesized fluorescent dye AZR that is efficient in fast and relatively inexpensive diagnostics of callus embryos that are problematic due to in vitro culture specificity.

Novel amidine derivatives of benzanthrone: Effect of bromine atom on the spectral parameters

Several new substituted amidine derivatives of benzanthrone were synthesized by condensation reaction from 2-bromo-3-aminobenzo[de]anthracen-7-one and appropriate aromatic or aliphatic amides. The novel benzanthrone derivatives were characterized by TLC analysis, NMR, IR, MS, UV/Vis, and fluorescence spectroscopy. The obtained derivatives have yellow or orange fluorescence in organic solvents. The solvent effect on photophysical behaviors of these dyes was investigated, and the results showed that the introduction of a bromine atom causes a blue-shift of the absorption and emission bands and decrease in the fluorescent quantum yield in comparison with unbromated analogues. The difference in the excited state and the ground state dipole moments was estimated by using the variation of Stokes shift and by semiempirical molecular calculations. The crystal structure and packing of four novel dyes has been revealed by the X-ray single crystal structure analysis.

Experimental and theoretical study on structure and spectroscopic properties of 2-bromo-3-N-(N',N'-dimethylformamidino) benzanthrone

The goal of present research is a theoretical and experimental investigation of geometrical structure, electronic properties, absorption and fluorescence spectra prediction for 2-bromo-3-N-(N',N'-dimethylformamidino)benzanthrone. As a result of conformational analysis, two rotamers have been found with a rotational barrier of 5.45 kcal/mol. Absorption and fluorescence spectra maxima in the solvent (ethanol) have been calculated using the concepts of the Jablonsky diagram. The obtained values of the absorption and fluorescence maxima (437 and 679 nm, respectively) correspond to the experimental values (447 and 659 nm). The abnormally large Stokes shift is associated with the redistribution of electron density, as well as flattening of the structure of the molecule in the excited state. According to the frontal molecular orbital analysis data, the peak in the long-wave part of the absorption spectra is created by an electron transition from the highest occupied molecular orbital (HOMO) to the lowest occupied molecular orbital (LUMO) (π→π*). Substitute group does not participate in the formation of absorption and fluorescence spectra.