MICROWAVE SPECTROSCOPY STUDY SUPPORTED BY QUANTUM CHEMISTRY CALCULATIONS OF LIMONA KETONE, A KEY OXIDATION PRODUCT OF LIMONENE

125 potential TADF candidates are identified through quantum chemistry calculations of 700 molecules derived from a database of 40 000 molecular semiconductors. Most of them are new and some do not belong to the class of donor–acceptor molecules.

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Understanding (coupled) large amplitude motions: the interplay of microwave spectroscopy, spectral modeling, and quantum chemistry

Physical Sciences Reviews ◽

10.1515/psr-2020-0037 ◽

2020 ◽

Vol 0 (0) ◽

Author(s):

Ha Vinh Lam Nguyen ◽

Isabelle Kleiner

Keyword(s):

Fourier Transform ◽

Quantum Chemistry ◽

Large Amplitude ◽

Environmental Chemistry ◽

Broad Band ◽

Microwave Spectroscopy ◽

Rotational Spectrum ◽

Spectral Modeling ◽

Rotational Spectra ◽

Large Amplitude Motions

AbstractA large variety of molecules contain large amplitude motions (LAMs), inter alia internal rotation and inversion tunneling, resulting in tunneling splittings in their rotational spectrum. We will present the modern strategy to study LAMs using a combination of molecular jet Fourier transform microwave spectroscopy, spectral modeling, and quantum chemical calculations to characterize such systems by the analysis of their rotational spectra. This interplay is particularly successful in decoding complex spectra revealing LAMs and providing reference data for fundamental physics, astrochemistry, atmospheric/environmental chemistry and analytics, or fundamental researches in physical chemistry. Addressing experimental key aspects, a brief presentation on the two most popular types of state-of-the-art Fourier transform microwave spectrometer technology, i.e., pulsed supersonic jet expansion–based spectrometers employing narrow-band pulse or broad-band chirp excitation, will be given first. Secondly, the use of quantum chemistry as a supporting tool for rotational spectroscopy will be discussed with emphasis on conformational analysis. Several computer codes for fitting rotational spectra exhibiting fine structure arising from LAMs are discussed with their advantages and drawbacks. Furthermore, a number of examples will provide an overview on the wealth of information that can be drawn from the rotational spectra, leading to new insights into the molecular structure and dynamics. The focus will be on the interpretation of potential barriers and how LAMs can act as sensors within molecules to help us understand the molecular behavior in the laboratory and nature.

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Adsorption and Desorption Mechanisms of Rare Earth Elements (REEs) by Layered Double Hydroxide (LDH) Modified with Chelating Agents

Applied Sciences ◽

10.3390/app9224805 ◽

2019 ◽

Vol 9 (22) ◽

pp. 4805 ◽

Cited By ~ 3

Author(s):

Shuang Zhang ◽

Naoki Kano ◽

Kenji Mishima ◽

Hirokazu Okawa

Keyword(s):

Rare Earth ◽

Quantum Chemistry ◽

Rare Earth Elements ◽

Adsorption Capacity ◽

Density Functional ◽

Stable State ◽

Experimental Result ◽

Adsorption And Desorption ◽

Adsorption Affinity ◽

Quantum Chemistry Calculations

In order to obtain the adsorption mechanism and adsorption structures of Rare Earth Elements (REEs) ions adsorbed onto layered double hydroxides (LDH), the adsorption performance of LDH and ethylenediaminetetraacetic acid (EDTA) intercalated LDH for REEs was investigated by batch experiments and regeneration studies. In addition to adsorption capacity, the partition coefficient (PC) was also evaluated to assess their true performance metrics. The adsorption capacity of LDH increases from 24.9 μg·g−1 to 145 μg·g−1 for Eu, and from 20.8 μg·g−1 to 124 μg·g−1 for La by intercalating EDTA in this work; and PC increases from 45.5 μg·g−1·uM−1 to 834 μg·g−1·uM−1 for Eu, and from 33.6 μg·g−1·μM−1 to 405 μg·g−1·μM−1 for La. Comparison of the data indicates that the adsorption affinity of EDTA-intercalated LDH is better than that of precursor LDH no matter whether the concept of adsorption capacity or that of the PC was used. The prepared adsorbent was characterized by XRD, SEM-EDS and FT-IR techniques. Moreover, quantum chemistry calculations were also performed using the GAUSSIAN09 program package. In this calculation, the molecular locally stable state structures were optimized by density functional theory (DFT). Both the quantum chemistry calculations and the experimental data showed that REEs ions adsorbed by EDTA-intercalated LDH are more stable than those adsorbed by precursor LDH. Furthermore, the calculation results of adsorption and desorption rates show that adsorption rates are larger for Eu(III) than for La(III), which agrees with the experimental result that Eu(III) has a higher adsorption ability under the same conditions. The LDHs synthesized in this work have a high affinity for removing REEs ions.

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Disentangling the complex network of non-covalent interactions in fenchone hydrates via rotational spectroscopy and quantum chemistry

Physical Chemistry Chemical Physics ◽

10.1039/d1cp02995a ◽

2021 ◽

Author(s):

Mhamad Chrayteh ◽

Ecaterina Burevschi ◽

Donatella Loru ◽

Therese R. Huet ◽

Pascal Dréan ◽

...

Keyword(s):

Quantum Chemistry ◽

Computational Chemistry ◽

Complex Network ◽

Microwave Spectroscopy ◽

Rotational Spectroscopy ◽

Non Covalent Interactions ◽

First Time ◽

Covalent Interactions

The hydrates of the monoterpenoid fenchone (C10H16O).(H2O)n (n=1,2,3) were investigated both by computational chemistry and microwave spectroscopy. Two monohydrates, three dihydrates and for the first time three trihydrates have been...

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