In this work, the interaction between an Auramine O (AuO) fluorescent molecular rotor and natural DNA, its thermodynamic aspects and the resulting variation of the optical properties upon binding are addressed by a combined spectroscopic (UV-vis and fluorescence) and computational approach. DNA binding causes a shift in the maximum of absorption from 432 nm to 444 nm, a decrease of the extinction coefficient and a dramatic enhancement of fluorescence emission, these results being in agreement with intercalation into the polynucleotide helix. Intercalation is indeed confirmed by the thermodynamic parameters for the binding reaction (in particular, the highly negative ΔH). Theoretical modelling at the TD-DFT level was done on a simplified model system consisting of the AuO molecule intercalated between two DNA base pairs. The evolution of the calculated vertical transitions quantitatively reproduces the experimentally observed hypo- and bathochromic shifts, thus confirming the intercalation hypothesis.
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http://dx.doi.org/10.1039/c9cp03071a | DOI Listing |
Heliyon
January 2025
Nuclear Chemistry Division, Department of Chemistry, Atomic Energy Commission, P. O. Box: 9061, Damascus, Syrian Arab Republic.
Molecular scale information is needed to understand ions coordination to mineral surfaces and consequently to accelerate the design of improved adsorbents. The present work reports on the use of two-dimensional correlation Fourier Transform infra-red spectroscopy (2D-COS-FTIR) and hetero 2D-COS-FTIR- X-ray diffraction (XRD) to probe the mechanism of Cr(VI) removal from aqueous solutions by activated carbon (AC) and its composite with PWO (AC-composite). The adsorption data at an initial Cr(VI) concentration of 320 mg L (320 ppm) revealed maximum adsorption capacities of 65 mg g for AC and 73 mg g for AC-composite, corresponding to removal percentages of 83 % and 94 %, respectively.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
January 2025
Central South University, material science and engineering, 932 Lushan Road, 410083, Changsha, CHINA.
Hydrogen bond (HB) chemistry, a pivotal feature of aqueous zinc-ion batteries, modulates electrochemical processes through weak electrostatic interactions among water molecules. However, significant challenges persist, including sluggish desolvation kinetics and inescapable parasitic reactions at the electrolyte-electrode interface, associated with high water activity and strong Zn2+-solvent coordination. Herein, a targeted localized HB docking mechanism is activated by the polyhydroxy hexitol-based electrolyte, optimizing Zn2+ solvation structures via dipole interaction and reconstructing interfacial HB networks through preferential parallel adsorption.
View Article and Find Full Text PDFNat Prod Res
January 2025
Department of Chemistry, Islamic University of Science and Technology, Awantipora, JK, India.
, a high-altitude medicinal herb, possesses diverse therapeutic properties. This study conducted a comprehensive phytochemical analysis of the whole plant, leading to the isolation of 15 secondary metabolites (1-15) across various classes: flavonoids (), triterpenoids (, ), sesquiterpenoid lactones (, ) and furanocoumarins (, ) along with three steroids (). These compounds were characterized using NMR (HNMR,C NMR, 2D NMR), IR, HRMS and UV-VIS.
View Article and Find Full Text PDFWe demonstrate a broadband photothermal spectroscopy in the mid-infrared region using a quantum cascade laser frequency comb operating between ∼7.7 and ∼8.2 µm covering a frequency range of ∼70 cm.
View Article and Find Full Text PDFWe developed a scanning dual-comb spectroscopic microscopy (S-DCSM) system to acquire multidimensional optical information of transparent or semi-transparent samples. The system demonstrated the capability to perform spectral imaging of absorbance, optical phase, optical thickness, linear dichroism, and birefringence within the spectral range covered by optical frequency combs (OFCs). The spatial distribution of optical thickness in HeLa cells was measured as 8.
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