Determining the Out-of-Plane Longitudinal Sound Speed in GeS by Broadband Time-Domain Brillouin Scattering.

Over the past decade, two-dimensional (2D) layered semiconducting materials, with their distinctive structures and unique physicochemical properties, have attracted attention for potential applications in photonics and optoelectronics. In this study, we utilized time-domain broadband Brillouin scattering on a single germanium monosulfide (GeS) crystal to determine the out-of-plane longitudinal sound speed, evaluated at vL = (4035 ± 200) m/s. The reported results demonstrate the effectiveness of this nondestructive, all-optical technique for measuring the elastic properties in fragile 2D layered materials and provide the value of the out-of-plane compressive elastic constant, C = (69 ± 7) GPa.

Solvent effects on the intramolecular charge transfer excited state of 3CzClIPN: a broadband transient absorption study.

The prediction of solvent properties using molecular probes often relies on correlating steady-state absorption and fluorescence measurements, as well as determining absorption maxima and/or Stokes shifts. In this study, we employ femtosecond broadband transient absorption (fs-bb-TA) spectroscopy to investigate the spectroscopic behaviour of the intramolecular charge transfer (ICT) excited state of 3CzClIPN (2,4,6-tri(9H-carbazol-9-yl)-5-chloroisophthalonitrile), a representative ICT organic molecule, in both aromatic and non-aromatic solvents. Unlike observations in non-aromatic media, fs-bb-TA spectra of 3CzClIPN in aromatic solvents exhibit enhanced spectral broadening that strongly correlates with the solvent's polarity. We hypothesise that this spectral broadening originates from a wider configurational energy landscape experienced by the positively charged carbazole Cz+ group, owing to the larger size and, consequently, reduced solvation effectiveness of aromatic solvent molecules.

Development of 1 H-NMR methods for quantitative determination of alkylamides in Zanthoxylum bungeanum and quality evaluation based on its fingerprint.

Alkylamides, as the representative hemp flavor and active ingredients, can reflect the quality of Zanthoxylum bungeanum Maxim. However, conjugated triene structure exists in alkylamides, which is easy to be oxidized and decomposed in air, making it difficult to quantify. In this study, a method for the quantitative determination of alkylamides by 1 H-NMR technology was developed with 85% ethanol as the best extraction solvent, CDCl3 as the best deuterium dissolution reagent, pyrazine as the internal standard, and triple peaks of hydrogen protons on the amide bond at δ 6.33 ppm as the quantitative signal peak. Meanwhile, methodological verification was carried out to prove the reliability and effectiveness of the method. On this basis, the contents of alkylamides in nine germplasms of Zanthoxylum with monthly dynamics were obtained. The results showed that the alkylamides of Hancheng stingless Z. bungeanum (HC) exhibited the highest content in August (51.92 ± 0.96 mg/g), while the lowest was FG in June (1.23 ± 0.21 mg/g). The results of 1 H-NMR corresponded to those of HPLC, and the effectiveness of this method was verified. Accumulation dynamic results show that the best harvest period of Z. bungeanum is July and August. Moreover, the quality of nine varieties of Zanthoxylum bungeanum from a common garden was evaluated by the established 1 H-NMR fingerprint and chemometric analyses. The results showed that Hancheng stingless Z. bungeanum was the best germplasm. This study provides a new strategy for the quantitative determination of alkylamides in Z. bungeanum and improves the quality evaluation system of Z. bungeanum. PRACTICAL APPLICATION: The results provide a new research idea for the analysis of important chemical components of Z. bungeanum. Meanwhile, the study provides a scientific basis for the quality evaluation and high-quality germplasm resources of Z. bungeanum.