Vibrational circular dichroism (VCD) was first applied to the stereochemical analysis of sphingosine. VCD patterns derived from the C═C stretch as well as other mid-infrared (IR) regions were practical markers to discriminate all the stereoisomers of intact sphingosine. Glutaraldehyde was found as an excellent derivatizing reagent for sphingosine which improves its solubility in VCD-friendly nonpolar solvents such as chloroform and enhances the VCD intensities by forming a rigid cyclized structure.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/acs.orglett.6b00477 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Anisotropy factor spectra for weakly allowed electronic transitions in chiral ketones.
Chemphyschem
December 2024
Freie Universität Berlin: Freie Universitat Berlin, Dahlem Center of Complex Quantum Systems and Fachbereich Physik, Arnimallee 14, 14195, Berlin, GERMANY.
Article Synopsis
- The study focuses on one-photon absorption and circular dichroism in three compounds: fenchone, camphor, and 3-methylcyclopentanone (3MCP).
- The results indicate that the transitions considered are weakly allowed, leading to significant anisotropies and necessitating the inclusion of non-Condon effects in theoretical models.
- Experimental data for 3MCP reveals that Herzberg-Teller corrections are essential to align theoretical predictions with observed features, underscoring the role of vibrational factors in electronic circular dichroism dynamics.
Ordered Aggregates of Fmoc-Diphenylalanine at Alkaline pH as a Precursor of Fibril Formation and Peptide Gelation.
J Phys Chem B
January 2025
Department of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104, United States.
The ultrashort peptide -fluorenylmethoxycarbonyl-phenylalanyl-phenylalanine (FmocFF) has been largely investigated due to its ability to self-assemble into fibrils (100 nm-μm scale) that can form a sample-spanning gel network. The initiation of the gelation process requires either a solvent switch (water added to dimethyl sulfoxide) or a pH-switch (alkaline to neutral) protocol, both of which ensure the solubility of the peptide as a necessary step preceding gelation. While the respective gel phases are well understood in structural and material characteristics terms the pregelation conditions are known to a lesser extent.
View Article and Find Full Text PDFStereo-Differentiating Asymmetric Rh(I)-Catalyzed Pauson-Khand Reaction: A DFT-Informed Approach to Thapsigargin Stereoisomers.
J Am Chem Soc
January 2025
Department of Chemistry, University of Pittsburgh, Pittsburgh, Pennsylvania 15260, United States.
We report a stereo-differentiating dynamic kinetic asymmetric Rh(I)-catalyzed Pauson-Khand reaction, which provides access to an array of thapsigargin stereoisomers. Using catalyst-control, a consistent stereochemical outcome is achieved at C2─for both matched and mismatched cases─regardless of the allene-yne C8 stereochemistry. The stereochemical configuration for all stereoisomers was assigned by comparing experimental vibrational circular dichroism (VCD) and C NMR to DFT-computed spectra.
View Article and Find Full Text PDF3D-printed acoustic metasurface with encapsulated micro-air-bubbles for frequency-selective manipulation.
Lab Chip
December 2024
College of Engineering and Applied Sciences, Nanjing University, Jiangsu 210093, China.
Acoustic waves provide an effective method for object manipulation in microfluidics, often requiring high-frequency ultrasound in the megahertz range when directly handling microsized objects, which can be costly. Micro-air-bubbles in water offer a solution toward low-cost technologies using low-frequency acoustic waves. Owing to their high compressibility and low elastic modulus, these bubbles can exhibit significant expansion and contraction in response to even kilohertz acoustic waves, leading to resonances with frequencies determined and tuned by air-bubble size.
View Article and Find Full Text PDFPerformance Assessment of a Piezoelectric Vibration Energy Harvester for Hybrid Excitation with Varying Cross Sections.
Sensors (Basel)
November 2024
Faculty of Mechanical Engineering, Lublin University of Technology, 36, 20-618 Lublin, Poland.
This paper experimentally examines the influence of hybrid excitation on the performance of vibrational piezoelectric energy harvesting systems on a bluff body with a variable cross section along its generatrix. A combination of vibrational excitation from a shaker and airflow is considered the source from which energy is harvested. Varied excitation frequencies and airflow velocities across five different masses were considered, each defining the natural frequency of the system.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!