scholarly journals Radical-initiated P,P-metathesis reactions of diphosphanes: evidence from experimental and computational studies

2021 ◽  
Author(s):  
Paul G. Pringle ◽  
Callum Branfoot ◽  
Tom Young ◽  
Duncan F Wass
Keyword(s):  
Dft Calculations ◽  
Computational Studies ◽  
Ambient Conditions ◽  
Metathesis Reactions

By combining the diphosphanes Ar2P–PAr2, where Ar = C6H5, 4-C6H4Me, 4-C6H4OMe, 3,5-C6H3(CF3)2, it has been shown that P,P-metathesis generally occurs rapidly under ambient conditions. DFT calculations have shown that the...

Computational studies on the interactions of glycine amino acid with graphene, h-BN and h-SiC monolayers

2017 ◽  
Vol 19 (3) ◽  
pp. 1896-1908 ◽  
Author(s):  
H. Tavassoli Larijani ◽  
M. Jahanshahi ◽  
M. Darvish Ganji ◽  
M. H. Kiani
Keyword(s):  
Density Functional Theory ◽  
Silicon Carbide ◽  
Amino Acid ◽  
Boron Nitride ◽  
Dft Calculations ◽  
Density Functional ◽  
Computational Studies ◽  
Functional Theory ◽  
Zwitterionic Form ◽  
Hexagonal Sheets

In the present work, the adsorption of glycine amino acid and its zwitterionic form onto three different hexagonal sheets, namely graphene, boron-nitride (h-BN) and silicon carbide (h-SiC), has been investigated within the framework of density functional theory (DFT) calculations.

Tropylium Salt Promoted Hydroboration Reactions: Mechanistic Insights via Experimental and Computational Studies

2021 ◽  
Author(s):  
Nhan Nu Hong Ton ◽  
Binh Khanh Mai ◽  
Thanh Vinh Nguyen
Keyword(s):  
Dft Calculations ◽  
Lewis Acids ◽  
Experimental Studies ◽  
Cross Coupling ◽  
Computational Studies ◽  
Metal Free ◽  
Hydride Abstraction ◽  
Novel Method ◽  
Tropylium Salts

Abstract: Hydroboration reaction of alkynes is one of the most synthetically powerful tools to access organoboron compounds, versatile precursors for cross coupling chemistry. This type of reaction has traditionally been mediated by transition metal or main group catalysts. Herein, we report a novel method using tropylium salts, typically known as organic oxidants and Lewis acids, to efficiently promote the hydroboration reaction of alkynes. A broad range of vinylboranes can be easily accessed via this metal-free protocol. Similar hydroboration reactions of alkenes and epoxides can also be efficiently catalyzed by the same tropylium catalysts. Experimental studies and DFT calculations suggested that the reaction follows an uncommon mechanistic paradigm, which is triggered by a hydride abstraction of pinacolborane with tropylium ion. This is followed by a series of <i>in situ</i> counterion-activated substituent exchanges to generate boron intermediates that promote the hydroboration reaction.

scholarly journals Computational studies of the unusual water adduct [Cp2TiMe(OH2)]+: the roles of the solvent and the counterion

2014 ◽  
Vol 43 (29) ◽  
pp. 11195-11201 ◽  
Author(s):  
Jörg Saßmannshausen
Keyword(s):  
Dft Calculations ◽  
Computational Studies ◽  
Nmr Data ◽  
Good Comparison

Detailed DFT calculations revealed that two molecules of CH2Cl2 are required to obtain a good comparison with the experimental NMR data.

Non-templated ambient nanoperforation of graphene: a novel scalable process and its exploitation for energy and environmental applications

Nanoscale ◽  
2015 ◽  
Vol 7 (46) ◽  
pp. 19705-19713 ◽  
Author(s):  
Suman Kumari Jhajharia ◽  
Kaliaperumal Selvaraj
Keyword(s):  
Dft Calculations ◽  
Specific Capacitance ◽  
High Specific Capacitance ◽  
Environmental Applications ◽  
Graphene Sheets ◽  
Ambient Conditions

A rapid, inexpensive and safely scalable nanoperforation process for graphene sheets at ambient conditions is reported herein. The holey graphene exhibits retainable high specific capacitance due to perforation. DFT calculations provide direct clues about the nanoscopic perforation.

scholarly journals Transition Metal Oxynitrides Catalysts for Electrochemical Reduction of Nitrogen to Ammonia

2021 ◽  
Author(s):  
Damilola Ologunagba ◽  
Shyam Kattel
Keyword(s):  
Density Functional Theory ◽  
Transition Metal ◽  
Dft Calculations ◽  
Electrochemical Reduction ◽  
Density Functional ◽  
Reduction Reaction ◽  
Ambient Conditions ◽  
Functional Theory ◽  
Nitrogen Reduction ◽  
Bosch Process

Electrochemical nitrogen reduction reaction (ENRR) at ambient conditions is beneficial compared to energy intensive thermochemical Haber-Bosch process for NH3 production. Here, periodic density functional theory (DFT) calculations are carried out...

scholarly journals Synthetic and Computational Studies on the ABC Trioxadispiroketal Subunit of the Marine Biotoxin Azaspiracid-1

2008 ◽  
Vol 3 (11) ◽  
pp. 1934578X0800301
Author(s):  
Jialiang Li ◽  
Xiaohua Li ◽  
David R. Mootoo
Keyword(s):  
Dft Calculations ◽  
Natural Product ◽  
Anomeric Effect ◽  
Computational Studies ◽  
Structural Factors ◽  
Substitution Pattern ◽  
Major Isomer ◽  
The Stability ◽  
Insight Into

The trioxadispiroketal residue in the marine biotoxin azaspiracid-1, which exists in a configuration capable of exhibiting a double anomeric effect, is believed to be the thermodynamically most stable bis-spiroketal diastereomer. In order to get insight into how structural factors affect this equilibrium, a simplified ABC trioxadispiroketal analog of azaspiracid-1 was synthesized and subjected to equilbration and computational studies. Compound 7, which represents a double anomeric effect was obtained as the major isomer, together with diastereomers 14 and 15, in a respective ratio of 62:22:16. DFT calculations for 7, 14 and 15 qualitatively matched this observation. These results suggest that while a double anomeric effect may play a major role in the stability of the trioxadispiroketal configuration in the more complex natural product, the substitution pattern of the C ring is also a contributing factor.

Structural, spectroscopic and computational studies on the monoclinic polymorph (form I) of potassium hydrogen disilicate (KHSi2O5)

2014 ◽  
Vol 78 (3) ◽  
pp. 609-622 ◽  
Author(s):  
D. Schmidmair ◽  
V. Kahlenberg ◽  
L. Perfler ◽  
D. M. Többens
Keyword(s):  
Raman Spectroscopy ◽  
Hydrogen Bonding ◽  
Dft Calculations ◽  
Phase I ◽  
Spectroscopic Data ◽  
Direct Methods ◽  
Computational Studies ◽  
Structural Investigations ◽  
Micro Raman Spectroscopy ◽  
Potassium Hydrogen

AbstractHydrothermal treatment of quartz with 2 M K2CO3solutions at 623 K and 1 kbar resulted in the formation of single crystals of the monoclinic polymorph of potassium hydrogen disilicate (KHSi2O5or KSi2O4(OH)). Basic crystallographic data of this so-called phase I at room conditions are as follows: space groupC2/m,a= 14.5895(10) Å,b= 8.2992(3) Å,c= 9.6866(7) Å, β = 122.756(10)°,V= 986.36(10) Å3,Z= 8. The structure was determined by direct methods and refined to a residual of R(|F|) = 0.0224 for 892 independent observed reflections withI> 2σ(I). The compound belongs to the group of chain silicates. It is based on crankshaft-likeviererdouble-chains running parallel to [010]. The H atoms are associated with silanol groups. Hydrogen bonding between neighbouring double-chains results in the formation of ∼5 Å wide slabs. The three crystallographically independent K cations with six to eight O ligands provide linkage (1) between the chains of a single slab or (2) between adjacent slabs. Structural investigations have been supplemented by micro-Raman spectroscopy. The interpretation of the spectroscopic data including the allocation of the bands to certain vibrational species has been aided by DFT calculations.

Oxidation of hydroquinones by a (salen)ruthenium(vi) nitrido complex

2016 ◽  
Vol 52 (76) ◽  
pp. 11430-11433 ◽  
Author(s):  
Jianhui Xie ◽  
Po-Kam Lo ◽  
William W. Y. Lam ◽  
Wai-Lun Man ◽  
Li Ma ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Computational Studies ◽  
Ambient Conditions ◽  
Electrophilic Attack

In the presence of pyridine, [RuVI(N)(L)(MeOH)]+ (L = N,N′-bis(salicylidene)-o-cyclohexyldiamine dianion) readily oxidizes hydroquinone to p-benzoquinone under ambient conditions. Experimental and computational studies suggest a mechanism that involves an initial electrophilic attack at the aromatic ring of hydroquinone by the nitrido ligand.

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