Reactions of hydrogen atoms with α-(alkylthio) carbonyl compounds. Time-resolved ESR detection and DFT calculations

2005 ◽  
Vol 31 (7-8) ◽  
pp. 633-641 ◽  
Author(s):  
Pawel Wisniowski ◽  
Krzysztof Bobrowski ◽  
Piotr Filipiak ◽  
Ian Carmichael ◽  
Gordon L Hug
Keyword(s):  
Dft Calculations ◽  
Carbonyl Compounds ◽  
Hydrogen Atoms ◽  
Time Resolved

Solvent Dependence of Structural Dynamics and Spin-flip Processes in 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (ortho-3CzBN)

2020 ◽  
Author(s):  
Masaki Saigo ◽  
Kiyoshi Miyata ◽  
Hajime Nakanotani ◽  
Chihaya Adachi ◽  
Ken Onda
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Structural Changes ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Solvent Dependence ◽  
Acetonitrile Solutions

We have investigated the solvent-dependence of structural changes along with intersystem crossing of a thermally activated delayed fluorescence (TADF) molecule, 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (o-3CzBN), in toluene, tetrahydrofuran, and acetonitrile solutions using time-resolved infrared (TR-IR) spectroscopy and DFT calculations. We found that the geometries of the S1 and T1 states are very similar in all solvents though the photophysical properties mostly depend on the solvent. In addition, the time-dependent DFT calculations based on these geometries suggested that the thermally activated delayed fluorescence process of o-3CzBN is governed more by the higher-lying excited states than by the structural changes in the excited states.<br>

Macropolyhedral Boron-Containing Cluster Chemistry. A Metallathiaborane from S2B17H17: Isolation and Characterisation of [(PMe2Ph)2PtS2B16H16]; A neo-arachno Ten-Vertex Cluster Shape, and the Constitution of the [arachno-B10H15]- Anion

2005 ◽  
Vol 70 (4) ◽  
pp. 430-440 ◽  
Author(s):  
Michael J. Carr ◽  
Michael G. S. Londesborough ◽  
Jonathan Bould ◽  
Ivana Císařová ◽  
Bohumil Štíbr ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Sodium Hydride ◽  
Hydrogen Atoms ◽  
Subsequent Reaction ◽  
Cluster Chemistry ◽  
Cluster Shape ◽  
Open Face

The deprotonation of S2B17H17 with sodium hydride and subsequent reaction with [PtCl2(PMe2Ph)2] gives the new macropolyhedral metallathiaborane [(PMe2Ph)2PtS2B16H16], of which the cluster consists of a conventional eleven-vertex nido {SB10} unit, fused, with two boron atoms in common, with a {PtSB8} unit of unique ten-vertex neo-arachno constitution and geometry. The latter geometry suggests a configuration for the previously structurally uncharacterised [B10H15]- anion; starting from this configuration, DFT calculations of structure and thence of boron nuclear shieldings, which are found very closely to mimic those found experimentally, thence support a fluxional structure for [B10H15]- with three {BHB(bridging)} and two {BH(endo)} hydrogen atoms around a six-membered open face.

scholarly journals Mechanistic insights for the photoredox organocatalytic fluorination of aliphatic carbons by anthraquinone using time-resolved and DFT studies

2017 ◽  
Vol 7 (4) ◽  
pp. 848-857 ◽  
Author(s):  
J. W. Kee ◽  
H. Shao ◽  
C. W. Kee ◽  
Y. Lu ◽  
H. S. Soo ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Dft Studies ◽  
Time Resolved

Nanosecond TAS and DFT calculations reveal mechanistic insights for photoredox fluorination of aliphatic C–H bonds and evidence of an anthraquinone–Selectfluor® exciplex.

scholarly journals 5-Methyl-1,3-phenylene bis[5-(dimethylamino)naphthalene-1-sulfonate]: crystal structure and DFT calculations

2019 ◽  
Vol 75 (7) ◽  
pp. 1079-1083
Author(s):  
Tanwawan Duangthongyou ◽  
Ramida Rattanakam ◽  
Kittipong Chainok ◽  
Songwut Suramitr ◽  
Thawatchai Tuntulani ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Energy Gap ◽  
Rotation Axis ◽  
Three Dimensional ◽  
Hydrogen Atoms ◽  
Lumo Energy ◽  
Compound C ◽  
Dansyl Group ◽  
Weak Hydrogen Bonds ◽  
Homo Lumo

The title compound, C31H30N2S2O6, possesses crystallographically imposed twofold symmetry with the two C atoms of the central benzene ring and the C atom of its methyl substituent lying on the twofold rotation axis. The two dansyl groups are twisted away from the plane of methylphenyl bridging unit in opposite directions. The three-dimensional arrangement in the crystal is mainly stabilized by weak hydrogen bonds between the sulfonyl oxygen atoms and the hydrogen atoms from the N-methyl groups. Stacking of the dansyl group is not observed. From the DFT calculations, the HOMO–LUMO energy gap was found to be 2.99 eV and indicates n→π* and π→π* transitions within the molecule.

Synthesis and photophysical properties of extended π conjugated naphthalimides

2017 ◽  
Vol 16 (4) ◽  
pp. 539-546 ◽  
Author(s):  
C. Rémy ◽  
C. Allain ◽  
I. Leray
Keyword(s):  
Charge Transfer ◽  
Dft Calculations ◽  
Photophysical Properties ◽  
Photoinduced Charge Transfer ◽  
Time Resolved ◽  
Time Resolved Spectroscopy ◽  
Td Dft ◽  
Photoinduced Charge

A series of π conjugated naphthalimide derivatives were prepared. Compounds display efficient photoinduced charge transfer in solution which was rationalized by time-resolved spectroscopy and modelled by TD-DFT calculations.

Ti-coated BC2N nanotubes as hydrogen storage materials

2013 ◽  
Vol 91 (7) ◽  
pp. 598-604 ◽  
Author(s):  
Seifollah Jalili ◽  
Farzad Molani ◽  
Jeremy Schofield
Keyword(s):  
Dft Calculations ◽  
Density Functional ◽  
Hydrogen Adsorption ◽  
Molecular Form ◽  
Hydrogen Storage Materials ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Adsorption Sites ◽  
Hydrogen Molecules ◽  
Bc2n Nanotubes

Density functional theory (DFT) calculations have been performed to investigate Ti adsorption on BC2N nanotubes and the hydrogen adsorption capacity of Ti-coated structures. Different adsorption sites have been examined for the Ti adatom, and it is found that the most stable structure has a configuration with alternating columns of carbon and boron–nitrogen hexagons. The DFT calculations indicate that an adsorbed Ti atom on a carbon hexagon can bind four hydrogen molecules in molecular form, while Ti atoms on boron–nitride hexagons can adsorb three hydrogen molecules and two hydrogen atoms. Based on the calculations, the gravimetric efficiency corresponding to decoration of 67% of six carbon rings with Ti adatoms is estimated to be 8 wt %. Computation of the charge transfer reveals that the Ti atom on BC2N is in a cationic state. In addition, Ti adsorption has a significant influence on the electronic structure of the nanotubes and allows for the conversion of nanotubes from semiconductors in the pristine state to conductors upon doping. The interactions between the nanotubes, the Ti atom and hydrogen molecules have also been analyzed using Dewar coordination and Kubas interactions.

scholarly journals Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

2021 ◽  
Vol 17 ◽  
pp. 1352-1359
Author(s):  
Tsutomu Kimura ◽  
Koto Sekiguchi ◽  
Akane Ando ◽  
Aki Imafuji
Keyword(s):  
Dft Calculations ◽  
Exchange Reaction ◽  
Carbonyl Compounds ◽  
Organometallic Reagents ◽  
Magnesium Exchange

A series of 1-heteroatom-substituted vinyl p-tolyl sulfoxides were prepared and treated with organometallic reagents to evaluate which combination of sulfoxides and organometallic reagents yielded alkynes the most efficiently. The use of 1-chlorovinyl p-tolyl sulfoxide and isopropylmagnesium chloride was optimal for this purpose. A variety of 1-chlorovinyl p-tolyl sulfoxides were prepared from carbonyl compounds and chloromethyl p-tolyl sulfoxide and were converted into alkynes via the sulfoxide/magnesium exchange reaction and subsequent Fritsch–Buttenberg–Wiechell (FBW) rearrangement of the resulting magnesium alkylidene carbenoids. The mechanism of the FBW rearrangement of magnesium alkylidene carbenoids was studied by using 13C-labeled sulfoxides and by using DFT calculations.

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