scholarly journals Theoretical Studies on The Mechanism of Pd2+-Catalyzed Regioselective C-H Alkylation of Indole With MesICH2CF3OTf

Author(s):  
Yao Shi ◽  
Hongsheng Ma ◽  
Jiaxuan Shao ◽  
chao deng

Abstract The reaction mechanism of Pd2+-catalyzed regioselective C–H alkylation of indole with MesICH2CF3OTf has been investigated by the density functional theory calculations. The reaction mechanism mainly contains four steps:C-H activation, oxidative addition, reductive elimination and ligands substitution. From our calculations, we find that the C-H activation step was realized by the acetate anion (-OAc) assisted CMD process and the transition state of C-H activation process is a square planar configuration. Moreover, the calculation results suggest that the regioselectivity of C-H bond alkylation of indole with MesICH2CF3OTf can be ascribed to the different stability of the CMD transition states in C-H activation step and different acidities of C-H bonds.

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1663
Author(s):  
Laixing Luo ◽  
Xing Zheng ◽  
Jianye Wang ◽  
Wu Qin ◽  
Xianbin Xiao ◽  
...  

Biomass chemical looping gasification (CLG) is a novel gasification technology for hydrogen production, where the oxygen carrier (OC) transfers lattice oxygen to catalytically oxidize fuel into syngas. However, the OC is gradually reduced, showing different reaction activities in the CLG process. Fully understanding the CLG reaction mechanism of fuel molecules on perfect and reduced OC surfaces is necessary, for which the CLG of ethanol using Fe2O3 as the OC was introduced as the probe reaction to perform density functional theory calculations to reveal the decomposition mechanism of ethanol into the synthesis gas (including H2, CH4, ethylene, formaldehyde, acetaldehyde, and CO) on perfect and reduced Fe2O3(001) surfaces. When Fe2O3(001) is reduced to FeO0.375(001), the calculated barrier energy decreases and then increases again, suggesting that the reduction state around FeO(001) favors the catalytic decomposition of ethanol to produce hydrogen, which proves that the degree of reduction has an important effect on the CLG reaction.


Computation ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 58
Author(s):  
Anastasia A. Shakirova ◽  
Felix N. Tomilin ◽  
Vladimir A. Pomogaev ◽  
Natalia G. Vnukova ◽  
Grigory N. Churilov ◽  
...  

Gd endohedral complexes of C82 fullerenols were synthesized and mass spectrometry analysis of their composition was carried out. It was established that the synthesis yields a series of fullerenols Gd@C82Ox(OH)y (x = 0, 3; y = 8, 16, 24, 36, 44). The atomic and electronic structure and properties of the synthesized fullerenols were investigated using the density functional theory calculations. It was shown that the presence of endohedral gadolinium increases the reactivity of fullerenols. It is proposed that the high-spin endohedral fullerenols are promising candidates for application in magnetic resonance imaging.


Crystals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1179
Author(s):  
Ahmed Boshaala ◽  
Abrahem F. Abrahem ◽  
Abdulla Ali Almughery ◽  
Nabil Al-Zaqri ◽  
Abdelkader Zarrouk ◽  
...  

The reaction of bidentate N-S-thione-Schiff base, (E)-benzyl 2-(1-(4-chlorophenyl)- ethylidene)hydrazinecarbodithioate, with Cu(NO3)2·3H2O produced a cis-Cu(II) complex. The molecular structure was confirmed and characterized by CHN-EA, FAB-MS, IR, and UV-Vis analyses. The XRD supported cis-isomer of the bis anionic bidentate N (azomethine) and S (thiol) ligand coordination mode in tetrahedrally distorted square planar, rarely reported in the literature. The results of the XRD-bond lengths were in perfect agreement with the density functional theory (DFT) calculation. DFT-calculated angles around the Cu(II) center displayed slightly less distortion around the metal center from those of XRD. Additionally, the thermal stability of the complex was evaluated via thermal gravimetric analysis (TGA). Two-dimensional fingerprint (2D-FP), Hirshfeld surface analysis (HSA), and molecular electrostatic potential (MEP) support the XRD-packing results with the existence of the H⸱⸱⸱Cl and CH⸱⸱⸱π bonds as the main interactions in the crystal lattice of the desired complex.


Author(s):  
Xuxin Kang ◽  
Wei Xu ◽  
Xiangmei Duan

Abstract Rechargeable batteries with superior electronic conductivity, large capacity, low diffusion barriers and moderate open circuit voltage have attracted amount attention. Due to abundant resources and safety, as well as the high voltage and energy density, potassium ion batteries (KIBs) could be an ideal alternative to next−generation of rechargeable batteries. Based on the density functional theory calculations, we find that the SnS2 monolayer expands greatly during the potassiumization, which limits its practical application. The construction of graphene/SnS2/graphene (G/SnS2/G) heterojunction effectively prevents SnS2 sheet from deformation, and enhances the electronic conductivity. Moreover, the G/SnS2/G has not only a high theoretical special capacity of 680 mAh/g, but an ultra−low K diffusion barrier (0.08 eV) and an average open circuit voltage (0.22 V). Our results predict that the G/SnS2/G heterostructure could be used as a promising anode material for KIBs.


2019 ◽  
Vol 48 (1) ◽  
pp. 168-175 ◽  
Author(s):  
Chao Deng ◽  
Yingxin Sun ◽  
Yi Ren ◽  
Weihua Zhang

Density functional theory calculations were carried out to study the reaction mechanism of the Rh(iii)-catalyzed regioselective C–H cyanation of indole and indoline with N-cyano-N-phenyl-para-methylbenzenesulfonamide (NCTS).


Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 430
Author(s):  
Lukas Kyvala ◽  
Maxim Tchaplianka ◽  
Alexander Shick ◽  
Sergii Khmelevskyi ◽  
Dominik Legut

We theoretically investigate the electronic and magnetic structure of Fe 2 Hf. The density functional theory calculations are shown to produce the negative, easy-plane, magnetic anisotropy in the hexagonal Fe 2 Hf. Antimony substitution suppresses the planar magnetization direction and favors the uniaxial magnetic anisotropy, in agreement with experimental observations. Our study suggests the possibility of the chemical control of the magnetic anisotropy in Fe 2 Hf by Sb substitution, and illustrates the potential of (Fe,Sb) 2 + x Hf 1 − x Laves phase alloys for the permanent magnet applications.


Author(s):  
M. Mirnezhad ◽  
R. Ansari ◽  
H. Rouhi ◽  
M. Faghihnasiri

The application of graphene as a nanosensor in measuring strain through its band structure around the Fermi level is investigated in this paper. The mechanical properties of graphene as well as its electronic structure are determined by using the density functional theory calculations within the framework of generalized gradient approximation. In the case of electronic properties, the simulations are applied for symmetrical and asymmetrical strain distributions in elastic range; also the tight-binding approach is implemented to verify the results. It is indicated that the energy band gap does not change with the symmetrical strain distribution but depend on the asymmetric strain distribution, increasing strain leads to band gap opening around the Fermi level.


2008 ◽  
Vol 07 (04) ◽  
pp. 505-515
Author(s):  
LIQIN XUE ◽  
GUOCHEN JIA ◽  
ZHENYANG LIN

The relative stability of the trans and cis isomers in the square planar palladium(II) complexes Pd ( I )( PPh 3)(η3- XCHC ( Ph ) CHR ) ( X = H , Me , CMe 3, CO 2 Me , P ( O )( OMe )2, and SO 2 H ; R = H , Me ) was investigated with the aid of the B3LYP density functional theory calculations. We examined how the substituents X, with different electronic properties, of the η3-allyl ligands affect the relative stability of the trans and cis isomers. Through the investigation, we were able to explain the trans/cis relative stability derived from the experimentally measured trans/cis isomer ratios in the palladium(II) complexes.


2016 ◽  
Vol 40 (1) ◽  
pp. 85-88 ◽  
Author(s):  
Zhenfeng Zhang ◽  
Nana Ma ◽  
Xiaopeng Xuan

An unusual CC⋯CO interaction has been discovered in (Z)-3-[(4-halogenphenyl)amino]-2-cyanoprop-2-enoates and rationalized by the density functional theory calculations.


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