The vibration band of the ring stretching (ν), the fundamental ring breathing (ν) and the Fermi resonance band of carbonyl stretching mixing with the overtone of the ring breathing (ν 2ν) have been investigated in solid ethylene carbonate (EC) and EC/CHCN and EC/CHCl binary mixture. Dimer structure with aggregation-induced spectral splitting model (AIS) was applied to calculate the vibration spectra using the B3LYP-D3/6-311+G (d,p) procedure. The noncoincidence effect (NCE) and concentration induced frequency shifts of the ν and ν could be well explained by AIS model based on the dimer structure. Four bands were observed with two in the isotropic and two in the anisotropic Raman spectra and their NCE value decreased with the decrease of EC volume fraction in the binary mixture, and finally disappeared. NCE value and the Fermi resonance constants of EC at different concentrations were calculated from the experimental data.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.saa.2022.121593 | DOI Listing |
Talanta
January 2025
MOE Key Laboratory for Analytical Science of Food Safety and Biology, College of Chemistry, Fuzhou University, Fuzhou, China. Electronic address:
The current surface-enhanced Raman scattering (SERS) substrates typically feature a single energy level, posing challenges in coordinating electromagnetic enhancement (EM) and chemical enhancement (CM), thereby limiting the sensitive detection of numerous crucial target molecules. In this study, novel aggregated nanorings (a-NRs) hybridizing Ag, Au and AgCl are constructed as SERS substrates. On one hand, the obtained a-NRs exhibit robust localized surface plasmon resonance absorption, whose wavelength can be tuned to match three commonly used laser wavelengths (532, 633 and 785 nm) to gain strong EM effect.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics and Arnold Sommerfeld Center for Theoretical Physics (ASC), Ludwig-Maximilians-Universität München, München, Germany.
Sci Rep
January 2025
Instituto de Alta Investigación, Universidad de Tarapacá, 1000000, Arica, Chile.
CuZnSn(S,Se) (CZT(S,Se)) thin films exhibit the characteristics necessary to be effective absorbers in solar cells. In this report, the room temperature experimental Raman scattering spectra, recorded at different excitation wavelengths, are systematically analyzed theoretically using the results of DFT harmonic frequencies calculations at the Γ-point for various modifications of kesterite (KS), stannite (ST), and pre-mixed Cu-Au (PMCA) crystal structures. The specific anharmonism-induced features in the spectra of CZT(S,Se) crystals are identified, and the spectral lineshapes at varied strengths of anharmonic interaction are simulated.
View Article and Find Full Text PDFNat Commun
December 2024
Department of Physics and Astronomy, Seoul National University, Seoul, 08826, Korea.
Fermi polarons are emerging quasiparticles when a bosonic impurity immersed in a fermionic bath. Depending on the boson-fermion interaction strength, the Fermi-polaron resonances exhibit either attractive or repulsive interactions, which impose further experimental challenges on understanding the subtle light-driven dynamics. Here, we report the light-driven dynamics of attractive and repulsive Fermi polarons in monolayer WSe devices.
View Article and Find Full Text PDFJ Phys Chem A
December 2024
Department of Chemistry, KAIST, Daejeon 34141, Republic of Korea.
A photodetachment and photoelectron spectroscopic study by employing a cryogenically cooled ion trap combined with a velocity-map imaging setup has been carried out to unravel the vibrational structures and autodetachment dynamics of the dipole-bound states (DBSs) of -, -, and -methylphenolate anions (-, -, and -CHPhO). The electron binding energy of the DBS increases monotonically with the increase of the neutral dipole moment to give respective values of 66 ± 15, 123 ± 18, or 154 ± 14 cm for the -, -, or -isomer. The different electron-donating effects of the methyl moieties in the three geometrically different isomers seem to be reflected in the experiment.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!