Experimental data are presented for the scattering of electrons by H2O between 17 and 250 meV impact energy. These results are used in conjunction with a generally applicable method, based on a quantum defect theory approach to electron-polar molecule collisions, to derive the first set of data for state-to-state rotationally inelastic scattering cross sections based on experimental values.
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http://dx.doi.org/10.1103/PhysRevLett.97.123202 | DOI Listing |
Dalton Trans
January 2025
Departamento de Física dos Materiais e Mecânica, Instituto de Física, Universidade de São Paulo, C. P. 66318, São Paulo, SP, 05508-090, Brazil.
Distortions in the porphyrin core from planarity can trigger a unique structure-property relationship, imparting its basicity, chemical stability, redox potential, and excited-state energetics, among other properties. The colour change promoted by such distortion is signed by red shifts in its electronic absorption spectra. The adsorption of guest -substituted free-base porphyrin species onto inorganic hosts, such as clay minerals (layered aluminium or magnesium silicates), is known to further promote colour changes.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Chemistry, KAIST, Daejeon, Republic of Korea.
Despite its profound significance, the molecular structural changes near the transition state, driven by the vibronic coupling, have remained largely unexplored, leaving a crucial aspect of chemical reactions shrouded in uncertainty. Herein, the dynamical behavior of the reactive flux on the verge of chemical bond breakage was revealed through the spectroscopic characterization of a large amplitude vibrational motion. Highly excited internal rotor states of S methylamine (CHND) report on the structural change as the molecule approaches the transition state, indicating that the quasi-free internal rotation is strongly coupled to the reaction coordinate as their energies near the maximum of the reaction barrier for the N-D chemical bond predissociation.
View Article and Find Full Text PDFChaos
January 2025
Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306, USA.
Traveling waves of excitation arise from the spatial coupling of local nonlinear events by transport processes. In corrosion systems, these electro-dissolution waves relay local perturbations across large portions of the metal surface, significantly amplifying overall damage. For the example of the magnesium alloy AZ31B exposed to sodium chloride solution, we report experimental results suggesting the existence of a vulnerable zone in the wake of corrosion waves where local perturbations can induce a unidirectional wave pulse or segment.
View Article and Find Full Text PDFMater Horiz
January 2025
School of Materials Science and Engineering, Energy Materials and Devices Key Lab of Anhui Province for Photoelectric Conversion, Anhui University, Hefei, Anhui 230601, China.
The triboelectric nanogenerator (TENG) has been proved to be a very promising marine energy harvesting technology. Herein, we have developed a high-performance triboelectric nanogenerator (SD-TENG) with low friction, high durability, swing-induced counter-rotating motion mechanism (SICRMM) and dual potential energy storage and release strategy (DPESRS). The unique counter-rotating motion mechanism enabled SD-TENG to convert the external linear and swing motion energy into rotation motion energy of the inner and outer cylinders, and then converted it into a controllable power output.
View Article and Find Full Text PDFPhys Chem Chem Phys
January 2025
Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
We present state-to-state differential cross sections for rotationally inelastic collisions of vibrationally excited NO XΠ ( = 9) with Ar using a near-counterpropagating molecular beam geometry. These were obtained using the stimulated emission pumping technique coupled with velocity map imaging. Collision energies well over ∼1 eV were achieved and rotational excitations up to ∼Δ = 60 recorded for the first time for inelastic collisions.
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