Some characteristic vibrational modes of acetone and chloroform change due to the azeotrope formation. The extend of interaction of these molecules has significant effects on some vibrational modes involved, depending on unit structure in azeotrope cluster. Besides (1)H NMR signals undergo some chemical shifts, which show the effect of oncoming molecules on the target molecule. FT-IR and (1)H NMR spectra of pure substances and corresponding azeotrope were recorded, mutual influences due to azeotrope formation based on mole ratio, boiling point and spectral changes has been discussed. Unit structure of cluster deduced by investigating fundamental frequency shifts and (1)H NMR chemical shifts.
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http://dx.doi.org/10.1016/j.saa.2004.12.046 | DOI Listing |
J Chem Phys
January 2025
State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China.
Identifying the diverse roles of disorderly packed atoms inside an amorphous solid has been a highly pursued but daunting task in glass physics. By analyzing the full-frequency vibrational modes of a model Cu50Zr50 glass, here, we classify the internal atoms into low-, subhigh-, and high-frequency ones that have different tendencies for rearrangements upon excitations. We find that low-frequency atoms are structurally unfavored and tend to aggregate.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus UAB, 08193 Bellaterra, Spain.
So far, the striking sign reversal in the near-ambient slope of the gap temperature dependence of colloidal CsPbCl perovskite nanocrystals (NCs) compared to its Br counterpart remains unresolved. Pure bromide NCs exhibit a linear gap increase with increasing temperature, to which thermal expansion and electron-phonon interaction equally contribute. In contrast, the temperature slope for the chlorine compound gap is clearly negative.
View Article and Find Full Text PDFNano Lett
January 2025
Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093-0309, United States.
The structural and chemical properties of metal nanoparticles are often dictated by their interactions with molecular ligand shells. These interactions are highly material-specific and can vary significantly even among elements within the same group or materials with similar crystal structure. In this study, we surveyed the heterogeneous interactions between an -terphenyl isocyanide ligand and Au and Ag nanoparticles (NPs) at the single-molecule limit.
View Article and Find Full Text PDFRSC Adv
January 2025
IMMM, Institut des Molécules et Matériaux du Mans Bd Charles Nicolle 72000 Le Mans France.
Samarium (Sm) modification is emerging as a powerful strategy to manipulate the electrical response of 0.8BiFeO-0.2BaTiO (BFBT) multiferroic ceramics.
View Article and Find Full Text PDFMicrosyst Nanoeng
January 2025
Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Nanoelectromechanical systems (NEMS) based on atomically-thin tungsten diselenide (WSe), benefiting from the excellent material properties and the mechanical degree of freedom, offer an ideal platform for studying and exploiting dynamic strain engineering and cross-scale vibration coupling in two-dimensional (2D) crystals. However, such opportunity has remained largely unexplored for WSe NEMS, impeding exploration of exquisite physical processes and realization of novel device functions. Here, we demonstrate dynamic coupling between atomic lattice vibration and nanomechanical resonances in few-layer WSe NEMS.
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