We present a rotational spectroscopy study of alpha-methoxy phenylacetic acid in the gas phase. This acid is a derivative of mandelic acid and is used in various organic reactions. The conformational landscape of alpha-methoxy phenylacetic acid was explored to gain insight into its intramolecular dynamics. A rich rotational spectrum was obtained using chirped-pulse Fourier transform microwave spectroscopy in the 2-8 GHz range. Five conformers out of six calculated low-energy forms were identified in the spectrum, and the assignment of the C singly substituted isotopologues for the lowest-energy conformer led to its accurate structure determination. Splitting patterns were analyzed and attributed to the internal rotation of a methyl top. The analysis of the non-covalent interactions within the molecule highlights the subtle balance in the stabilization of the different conformers. We thus provide high-level structural and intramolecular dynamics information that is also used to benchmark the performance of quantum-chemical calculations.
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http://dx.doi.org/10.1039/d2cp03962a | DOI Listing |
Food Chem
June 2024
College of Food Science and Engineering & Institute of Special Oilseed Processing and Technology, Henan University of Technology, Zhengzhou 450001, China.
Chinese quince (Chaenomeles sinensis) fruit is an underutilized resource, rich in proanthocyanidins with antioxidant ability but poor lipid solubility. In this study, a novel modified oligomeric proanthocyanidin (MOPA) was prepared, which exhibited favorable lipid solubility (354.52 mg/100 g).
View Article and Find Full Text PDFInt J Biol Macromol
February 2024
Laboratory of Quantum and Statistical Physics LR 18 ES 18, Faculty of Sciences of Monastir, Environnement Street, 5019, Monastir, Tunisia.
In this work, an adsorption phenomenon putatively involved in the olfactory sense of phenylacetic acid, 4-chlorophenylacetic acid, and 4-methoxyphenylacetic acid pheromones in the Zebrafish olfactory receptor ORA1 was a helpful mechanism in interpreting and characterizing the olfaction process at a molecular level. Hence, the experimental dose-olfactory response curves were fitted by applying the one-layer adsorption model with a single energy (1LM1E). On one hand, the different parameters introduced in the selected model were used to microscopically study the three olfactory systems.
View Article and Find Full Text PDFFour-wave mixing (FWM) enables the generation and amplification of light in spectral regions where suitable fiber gain media are unavailable. The 1300 nm and 900 nm regions are of especially high interest for time-encoded (TICO) stimulated Raman scattering microscopy and spectro-temporal laser imaging by diffracted excitation (SLIDE) two-photon microscopy. We present a new, to the best of our knowledge, FWM setup where we shift the power of a home-built fully fiber-based master oscillator power amplifier (MOPA) at 1064 nm to the 1300-nm region of a rapidly wavelength-sweeping Fourier domain mode-locked (FDML) laser in a photonic crystal fiber (PCF) creating pulses in the 900-nm region.
View Article and Find Full Text PDFSensors (Basel)
January 2023
National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150001, China.
A temporal pre-shaped burst-mode hybrid fiber-bulk laser system was illustrated at a 10 kHz rate with a narrow spectral linewidth. A theoretical model was proposed to counteract the temporal profile distortion and compensate for the desired one, based on reverse process of amplification. For uniformly modulated injection, amplified shapes were recorded and investigated in series for their varied pulse duration, envelope width and amplification delay, respectively.
View Article and Find Full Text PDFDalton Trans
January 2023
Departament de Química Inorgànica i Orgànica, Secció de Química Inorgànica, Universitat de Barcelona, Martí i Franquès 1-11, 08028 Barcelona, Spain.
The reaction of Ln(NO)·6HO (Ln = Eu, Tb, Dy and Sm) with ()-(-)-α-methoxyphenylacetic acid (R-HMPA) and 1,10-phenanthroline (phen) in EtOH/HO allows the isolation of 1D chiral compounds of formula [Ln(μ--MPA)(-MPA)(phen)] in which Ln = Eu (R-Eu), Tb (R-Tb), Dy (R-Dy) and Sm (R-Sm). The same synthesis by using ()-(+)-α-methoxyphenylacetic acid (S-HMPA) instead of ()-(-)-α-methoxyphenylacetic acid allows the isolation of the enantiomeric compounds with formula [Ln(μ--MPA)(-MPA)(phen)] where Ln = Eu (S-Eu), Tb (S-Tb), Dy (S-Dy) and Sm (S-Sm). Single crystal X-Ray diffraction measurements were performed for compounds R/S-Eu, R/S-Tb, S-Dy and S-Sm.
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