Charge-controlled switchable methane adsorption on heteroatom-doped BNNSs

RSC Advances ◽  
2016 ◽  
Vol 6 (6) ◽  
pp. 5079-5088 ◽  
Author(s):  
Abdolvahab Seif ◽  
Khaled Azizi

The adsorption behavior of methane (CH4) on neutral and charged states of Al-, C-, P- and Si-doped boron nitride nanosheets (BNNSs), is investigated using the density functional theory (DFT) method.

RSC Advances ◽  
2016 ◽  
Vol 6 (63) ◽  
pp. 58458-58468 ◽  
Author(s):  
Abdolvahab Seif ◽  
Khaled Azizi

The adsorption behavior of hydrogen molecule (H2) on neutral and charged states of C-, Si- and P-doped boron nitride nanosheets (BNNSs), is investigated using density functional theory (DFT) method.


2015 ◽  
Vol 17 (34) ◽  
pp. 22448-22454 ◽  
Author(s):  
K. Zberecki ◽  
R. Swirkowicz ◽  
J. Barnaś

Conventional and spin related thermoelectric effects in zigzag boron nitride nanoribbons are studied theoretically within the Density Functional Theory (DFT) approach.


RSC Advances ◽  
2016 ◽  
Vol 6 (38) ◽  
pp. 31968-31975 ◽  
Author(s):  
Shuai Zhao ◽  
Liguo Gao ◽  
Chunfeng Lan ◽  
Shyam S. Pandey ◽  
Shuzi Hayase ◽  
...  

In this work, we present a detailed first-principles investigation on the stoichiometric and oxygen-deficient structures of double perovskites, Sr2BMoO6 (B = Mg, Co and Ni), using the density functional theory (DFT) method.


2020 ◽  
Author(s):  
Saeedeh Mohammadi ◽  
Mohammad Esmailpour ◽  
Mina Mohammadi

Abstract This paper is a new step in helping the treatment of coronavirus by improving the performance of chloroquine drug. For this purpose, we propose a complex of chloroquine drug with graphene nanoribbon (GNR) scheme. We compute the structural and electrical properties and absorption of chloroquine (C18H26ClN3) and GNR complex using the density functional theory (DFT) method. By creating a drug and GNR complex, the density of states of electrons increases and the energy gap decreases compared to the chloroquine. Also, using absorption calculations and spectrums such as infrared and UV-Vis spectra, we showed that GNR is a suitable structure for creating chloroquine drug complex. Our results show that the dipole moment, global softness and electrophilicity for the drug complex increases compared to the non-complex state. Our calculations can be useful for increasing performance and reducing the side effects of chloroquine, and thus can be effective in treating coronavirus.


Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 359 ◽  
Author(s):  
Hanwei Li ◽  
Mingliang Luo ◽  
Guohong Tao ◽  
Song Qin

Computational investigations on the bisphospholanoethane (BPE)-ligated Cu-catalyzed enantioselective addition of enynes to ketones were performed with the density functional theory (DFT) method. Two BPE-mesitylcopper (CuMes) catalysts, BPE-CuMes and (S,S)-Ph-BPE–CuMes, were employed to probe the reaction mechanism with the emphasis on stereoselectivity. The calculations on the BPE-CuMes system indicate that the active metallized enyne intermediate acts as the catalyst for the catalytic cycle. The catalytic cycle involves two steps: (1) ketone addition to the alkene moiety of the metallized enyne; and (2) metallization of the enyne followed by the release of product with the recovery of the active metallized enyne intermediate. The first step accounts for the distribution of the products, and therefore is the stereo-controlling step in chiral systems. In the chiral (S,S)-Ph-BPE–CuMes system, the steric hindrance is vital for the distribution of products and responsible for the stereoselectivity of this reaction. The steric hindrance between the phenyl ring of the two substrates and groups at the chiral centers in the ligand skeleton is identified as the original of the stereoselectivity for the titled reaction.


2010 ◽  
Vol 09 (supp01) ◽  
pp. 65-75 ◽  
Author(s):  
JING LI ◽  
WAN-YI JIANG

The trimethylamine-catalyzed Baylis–Hillman reaction of formaldehyde and vinylaldehyde has been studied with the density functional theory (DFT) method of B3LYP/6-31+G(d,p). In the gas phase, the reaction involves an amine–formaldehyde–vinylaldehyde trimolecular addition transition structure followed by rate-determining intramolecular 1,3-hydrogen shift. When a bulk solvent effect of water was considered with conductor-like polarizable continuum model (CPCM), the reaction was found to follow the sequence of Michael-addition of amine to vinylaldehyde (step 1), addition of formaldehyde (step 2), and 1,3-hydrogen shift (step 3), with the 1,3-hydrogen shift as rate-determining. The overall reaction barrier is significantly reduced. When a molecule of water is involved in the reaction, the 1,3-hydrogen shift is significantly promoted so that the rate-determining step becomes the C–C bond formation. The calculated overall reaction barrier is in agreement with experimental observations.


Author(s):  
V. A. Babkin ◽  
D. S. Andreev ◽  
E. S. Titova ◽  
A. V. Ignatov ◽  
R. O. Boldyrev ◽  
...  

In this work, we performed a quantum-chemical calculation of some epoxy molecules: 1,2-epoxy-butene, 1,2-epoxy-2-methylpropane, 1,2 epoxyethane by the density functional theory DFT. An optimized geometric and electronic structure of these compounds is obtained. It was found that the studied epoxides belong to the class of very weak СH-acids (pKa = 28-30).


2019 ◽  
Vol 9 (2) ◽  
pp. 133-141
Author(s):  
Abdelhak Ouled Aitouna ◽  
Lahoucine Bahsis ◽  
Hicham Ben El Ayouchia ◽  
Ahmed Chekroun ◽  
Redouan Hammal ◽  
...  

In this work the epoxidation reaction of the α- and ɣ-trans himachalene in the presence of meta chloroperoxybenzoic acid (m-CPBA) has been studied within the Density Functional Theory (DFT) method at the B3LYP/6-311G(d,p) level in dichloromethane as a solvent, in order to shed light on the chemo- and stereoselectivity in the course of the reaction. Analysis of the Conceptual Density Functional Theory (CDFT) reactivity indices indicate that the m-CPBA will behave as electrophilic while α- and ɣ-trans himachalene will behave as a nucleophile and the attacks observed experimentally are correctly predicted by the electrophilic Pk + and nucleophilic Pk - Parr functions. The two reactive paths associated with chemo and stereoselectivity approach modes of m-CPBA on C=C reactive sites in α and ɣ-trans himachalene have been analyzed. They showed that m-CPBA reacted as electrophile whereas α- and ɣ- trans himachalene as a nucleophile. The Monoepoxidation of α- and ɣ- trans himachalene leads to the formation of two stereoisomers, on the most substituted double bond "C=C», one of the two is a majority. The diepoxidation reaction of α- and ɣ- trans h


2011 ◽  
Vol 8 (2) ◽  
pp. 609-614 ◽  
Author(s):  
Mohammad T. Baei ◽  
F. Kaveh ◽  
P. Torabi ◽  
S. Zahra Sayyad- Alangi

The density functional theory (DFT) has been used to simultaneously investigate physic/chemi-sorption properties of oxygen on the (5, 5) boron nitride nanotube (BNNT). Geometry optimizations were carried out at B3LYP/6-31G*level of theory using gaussian 98 suites of program. physisorption of O2outside the BNNT with a vertical orientation to the tube axis above a boron atom is the most stable state of physisorption and its binding energy is -0.775 kcal/mol. In the chemisorption of O2molecule, the most stable state is above two adjacent B and N atoms of a hexagon with a B-N bond length of 2.503 Å and the binding energy of adsorbed oxygen atoms -14.389 kcal/mol. Based on these results, We also provide the effects of O2adsorption on the electronic properties of BNNTs.


2014 ◽  
Vol 997 ◽  
pp. 264-267
Author(s):  
Hong Ya Li ◽  
Tian Tian Zhang

N-2’,4’-dinitrophenyl-3,3-dinitroazetidine (DNPDNAZ) is an important derivative of 3,3-dinitroazetidine (DNAZ). The density functional theory (DFT) method of the Amsterdam density functional (ADF) was used to calculate the geometry and frequencies. The detonation velocity (D) and detonation pressure (P) of DNPDNAZ were estimated using the nitrogen equivalent equation according to the experimental density. Results showed that the initial decomposition step of DNPDNAZ is the loss of NO2from C2 and N1 is the point of molecular reactivity,DandPare 7364.42 m·s-1and 23.75 GPa, respectively.


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