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[Display omitted] • The fluorescence quenching of the probes P1 and P2 is due to the PET process, while the strong fluorescence of P3 originates from the ICT process. • The differences in hydroxyl positions and deprotonation are responsible for the different intramolecular interactions of the products. • The deprotonated form of the product is the real experimental product, and only this product emits strong fluorescence in the NIR fluorescence region. As one of the gaseous signaling molecules in biological systems, hydrogen sulfide(H 2 S) is involved in numerous physiological processes and diseases. Therefore, rapid, effective, and real-time detection of H 2 S is of great importance. Based on its excellent optical properties, dicyanoisophorone has attracted much attention in recent years, and a large number of corresponding probes have been developed to detect H 2 S in biological systems. In this paper, the fluorescence mechanisms of three dicyanoisophorone-based fluorescent probes are investigated and the near-infrared (NIR) fluorescence attribution of the products is discussed by density-functional theory and time-dependent density-functional theory methods. Frontier molecular orbital analysis shows that the non-fluorescence of the probes is attributed to the photo-induced electron transfer process. Structural change and reduced density gradient analyses indicate that the position of the hydroxyl group and the deprotonation have a non-negligible influence on the interactions within the products. The five- or six-membered ring-like structures formed by interactions make the molecule stain as a planar and the fluorescence emission, while the twist exists the fluorescence quenching. In addition, spectral information shows that the emission of NIR fluorescence originates from the deprotonated form of the product. [ABSTRACT FROM AUTHOR]

[Display omitted] • The role of C, C + H, CH and CH + H in hydrogen permeation was determined. • Minimum energy pathways for hydrogen diffusion were explored by CI-NEB method. • C atom in carbon-containing species controls inhibitory effect. • Substrate relaxation greatly reduce hydrogen diffusion barrier. This paper investigates the role of carbon-containing impurities (i.e. C, C + H, CH, and CH + H) playing in hydrogen diffusion into Pd(1 0 0) subsurface. Energetics and structures for adsorptions and absorptions of hydrogen were explored with variational coverages and locations of adsorbates by density functional theory, and then minimum energy pathways were cautiously searched out by climbing image nudged elastic band method. Surface relaxation and reconstruction effects were also concerned. Quantum simulations reveal that C and CH strongly bond to hollow site and lead to charge density redistribution and structural change of Pd(1 0 0) surface, and thus predominantly affect hydrogen penetration behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] • Doping B, N, P can enhance the electrical conductivity and adsorption properties of GeC monolayers. • The stability of the three adsorption structures was in the order of C2H2 > CH4, and the increase of Qt and the decrease of bandgap indicated that the conductivity of the adsorbed system was improved. • it was shown that the monolayer of P-GeC has the most optimal adsorption behaviour and reusability for C2H2. In this paper, the stability, electronic structure and optical properties of monolayer GeC, B, N and P doped GeC systems are systematically investigated based on the first principles of density functional theory. The results show that the results show that the intrinsic GeC monolayer has a weak adsorption capacity for CH 4 and C 2 H 2 , which is unfavourable for the sensing and trapping of CH 4 and C 2 H 2 gases. Based on calculated adsorption distance, adsorption energy and charge transfer, we find that P-GeC monolayer is the most sensitive to CH 4 and C 2 H 2 molecules, and the most of gas molecules act as acceptors to gain electrons from GeC monolayer. The adsorption energy of CH 4 is smaller than that of C 2 H 2 gas molecule, which implies that C 2 H 2 is more easily desorbed from P-GeC. Moreover, the work function changes significantly when gas molecules adsorbed on B, N, P-GeC, and Recovery times indicate that B, N and P doped GeC monolayers are more selective and sensitive to C 2 H 2 molecules compared to CH4 molecules. The research work aims to provide a theoretical basis for the application of GeC-based gas sensors, and P-doped GeC monolayers can be used as candidate materials for C 2 H 2 gas sensing and trapping. [ABSTRACT FROM AUTHOR]

Synopsis: The binding of auranofin-derived gold(I) fragment at DNA and RNA nucleobases. [Display omitted] • Repurposing of gold(I) metallodrugs may lead to new anticancer approaches. • A tremendous cytotoxic potential by the targeting of DNA/RNA nucleobases. • The structure and stability of gold(I)-nucleobases adducts via DFT. • Auranofin-derived [Et 3 PAu]+ cation binds effectively at purine nucleobases. • UV–vis spectrophotometry to quantify the ratio of [Et 3 PAu]+-nucleobase adducts. A variety of therapies are based on cytotoxicity induced via hampering the DNA and/or RNA homeostasis. The metallodrugs' forerunner, cisplatin, is exemplificative of the tremendous biological effects of nucleobase targeting, and a large body of researches to discover novel metallodrugs. In this paper, DFT approaches were employed to investigate the structure, stability and electronic properties of the complexes formed by the [Et 3 PAu]+ metal fragment generated by auranofin -or its derivatives- and the DNA/RNA nucleobases. Therefore, TDDFT calculations were performed to assess the viability of the spectrophotometric quantification of the [Et 3 PAu]+-nucleobase adducts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The enthalpy of formation, the calculated results show that the M−TiAl 3 compounds are all negative values, indicating that they are easy to form. • The structures of Sc-TiAl 3 and V-TiAl 3 are the most stable. The ability of Sc-TiAl 3 to resist volume deformation and shear deformation is larger. • In the M−TiAl 3 compound, except for Ni-TiAl 3 , the B: G value and Poisson's ratio ν are less than 1.75 and 0.33, respectively, showing a brittle material. Their intrinsic Vickers hardness is arranged in the order of Cr-TiAl 3 > TiAl 3 > V-TiAl 3 > Mn-TiAl 3 > Sc-TiAl 3 > Co-TiAl 3 > Ni-TiAl 3. In this paper, the elastic and electronic properties of Metal (M = Co, Cr, Mn, Ni, Sc) - TiAl 3 are compared based on the first-principles calculation method based on density functional theory, and the Metal-TiAl 3 Mechanical, thermodynamic and electronic properties of TiAl 3 intermetallic compounds. The results of mechanical property calculations show that the structures of Sc-TiAl 3 and V-TiAl 3 are the most stable. The ability of Sc-TiAl 3 to resist volume deformation and shear deformation is larger. The Poisson's ratio ν is less than 0.33, and it can be determined that the calculated compounds are brittle materials (except Ni-TiAl 3). Cr-TiAl 3 has the largest intrinsic Vickers hardness, while Ni-TiAl 3 has the smallest intrinsic Vickers hardness. This study has a significant impact on adjusting the mechanical properties of TiAl 3. [ABSTRACT FROM AUTHOR]

In this paper we address the potential entanglement of potassium ions mediated by interaction with a graphene sheet using DFT. The system consists of a neutral graphene sheet (G Q D) positioned equidistant between two positively charged potassium ions (K +). The entanglement is strongly influenced by the K + @ G Q D @ K + separation distance, in which it is possible to observe specific electronic transitions originating exclusively from the GQD to the potassium ions, enabling the acquisition of entangled states between the two ions with fidelity close to unity, demonstrating the potential of the present system for a robust generation of quantum entanglement between alkali metal ions. [Display omitted] • High-fidelity entanglement in potassium ions mediated by a graphene sheet is obtained. • DFT is used to modulate entanglement, revealing insights into GQD-K＋ transitions. • The results confirm GQD-K＋ system's potential in quantum technology applications. [ABSTRACT FROM AUTHOR]