Background: The study was aimed at investigating the effect of various solvents on the absorption spectra of Neutral Red, a dye belonging to the quinone-imine class of dyes. The solvents chosen for the study were water, ethanol, acetonitrile, acetone, propan-1-ol, chloroform, nitrobenzene, ethyleneglycol, acetic acid, DMSO and DMF.
Results: The results have shown that the absorption maxima of dyes are dependent on solvent polarity. In non-hydrogen-bond donating solvents, solvation of dye molecules probably occurs via dipole-dipole interactions, whereas in hydrogen-bond donating solvents the phenomenon is more hydrogen bonding in nature. To estimate the contribution of the different variables on the wave number of the Neutral Red dye, regression analyses using the ECW model were compared with the pi* scale model. This showed that the unified scale for estimating the solvent effect on the absorption of the Neutral Red dye is more adopted and more applicable than the pi* scale model.
Conclusion: Absorption maxima of dyes are dependent on solvent polarity. Solvation of dye molecules probably occurs via dipole-dipole interactions in non-hydrogen-bond donating solvents, whereas in hydrogen-bond donating solvents the phenomenon is more hydrogen bonding in nature. The unified scale for estimating the solvent effect on the absorption of Neutral Red dye is more adopted and more applicable than the pi* scale model. This may be due to complications from both pi-pi* charge transfer interactions and incomplete complexation of the solute; these effects are averaged out in the derived beta and pi parameters and thus limit their applicability.
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http://dx.doi.org/10.1186/1752-153X-2-19 | DOI Listing |
Dalton Trans
January 2025
Department of Chemistry, Handique Girls' College, Guwahati 781001, Assam, India.
Photoactive complexes of bioessential 3d metals, activable within the phototherapeutic window (650-900 nm), have gained widespread interest due to their therapeutic potential. Herein, we report the synthesis, characterization, and light-enhanced anticancer and antibacterial properties of four new dinuclear Co(II) complexes: [Co(phen)(cat)] (Co-1), [Co(dppz)(cat)] (Co-2), [Co(phen)(esc)] (Co-3), and [Co(dppz)(esc)] (Co-4). In these complexes, phen (1,10-phenanthroline) and dppz (dipyrido[3,2-:2',3'-]phenazine) act as neutral N,N-donor ligands, while cat and esc serve as O,O-donor catecholate ligands derived from catechol (1,2-dihydroxybenzene) and esculetin (6,7-dihydroxy coumarin).
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January 2025
Institute of Atomic and Molecular Sciences, Academia Sinica Taipei 106 Taiwan
Extreme ultraviolet (EUV) lithography is a cutting-edge technology in contemporary semiconductor chip manufacturing. Monitoring the EUV beam profiles is critical to ensuring consistent quality and precision in the manufacturing process. This study uncovers the practical use of fluorescent nanodiamonds (FNDs) coated on optical image sensors for profiling EUV and soft X-ray (SXR) radiation beams.
View Article and Find Full Text PDFInorg Chem
January 2025
Jiangsu Key Laboratory for Biomaterials and Devices, State Key Laboratory of Digital Medical Engineering, School of Biological Science and Medical Engineering, Southeast University, Nanjing 211189, PR China.
Organic-inorganic hybrid perovskites (OIHPs) have attracted enormous attention owing to their intriguing structural tunability and diverse functional properties. Reconstructive phase transitions, involving the breaking and reconstruction of chemical bonds, have rarely been found in such materials; however, these features may induce many intriguing physical properties in optics, ferroelectrics, ferromagnetics, and so forth. Here, we utilized the weak and switchable coordination bonds of HETMA-MnCl (HETMA = (2-hydroxyethyl) trimethylammonium) to construct a 1D hybrid perovskite employing a neutral framework.
View Article and Find Full Text PDFeNeuro
January 2025
Department of Computer Science and Engineering, Toyohashi University of Technology, Toyohashi 441-8580, Japan
The relationships between facial expression and color affect human cognition functions such as perception and memory. However, whether these relationships influence selective attention and brain activity contributed to selective attention remains unclear. For example, reddish angry faces increase emotion intensity, but it is unclear whether brain activity and selective attention are similarly enhanced.
View Article and Find Full Text PDFCommun Biol
January 2025
Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC), Madrid, E-28029, Spain.
The frequency of mitochondrial DNA haplogroups (mtDNA-HG) in humans is known to be shaped by migration and repopulation. Mounting evidence indicates that mtDNA-HG are not phenotypically neutral, and selection may contribute to its distribution. Haplogroup H, the most abundant in Europe, improved survival in sepsis.
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