scholarly journals NMR spectroscopy and ion pairing: Measuring and understanding how ions interact

2009 ◽  
Vol 81 (4) ◽  
pp. 615-633 ◽  
Author(s):  
Paul S. Pregosin
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Density Functional ◽  
Spin Echo ◽  
Ion Pairing ◽  
Functional Theory ◽  
Nmr Data ◽  
Insight Into ◽  
Qualitative Estimation

Pulsed gradient spin-echo (PGSE) diffusion and Overhauser NMR data together with density functional theory (DFT) calculations afford a qualitative estimation of the amount of ion pairing, as well as insight into the structures of a variety of inorganic, organic, and organometallic salts.

Hexaethyl-2,4-dicarba-nido-hexaborane(8), Deprotonation and Complexation Studied by NMR Spectroscopy and Density Functional Theory (DFT) Calculations

2004 ◽  
Vol 59 (6) ◽  
pp. 685-691 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Chemical Shifts ◽  
Coupling Constants ◽  
Analogous Reaction ◽  
Sandwich Complex ◽  
Dft Methods ◽  
Functional Theory ◽  
Nmr Data

Deprotonation of hexaethyl-2,4-dicarba-nido-borane(8) 2 leads first to the hexaethyl-2,4-dicarbanido- borate(1−) 3, and further deprotonation, using BuLi/KOtBu, gives the hexaethyl-2,4-dicarbanido- hexaborate(2−) 4. The reaction of 3 with FeCl2 affords the commo-ferracarborane [Fe(Et6-2,4- C2B4H)2] 5, and the analogous reaction of 4 leads to the anionic sandwich complex [Fe(Et6-2,4- C2B4)2]2− 6 which can be protonated to give 5. The complex 5 contains two hydrido ligands, each bridging the iron and two boron atoms. Reactions were monitored and the products were characterised by 11B NMR spectroscopy in solution. The geometries of the carboranes, the borates (all unsubstituted and permethyl-substituted) and the iron complexes (all unsubstituted) were optimised by DFT methods [B3LYP/6-311+G(d,p) or B3LYP/6-31+G(d)], and the relevant NMR data [chemical shifts δ11B, δ13C, δ57Fe, and coupling constants 1J(13C,1H), 1J(11B,1H), 1J(57Fe,1H), 1J(57Fe,11B)] were calculated at the same level of theory.

Insight into the structure and morphology of Run clusters on Co(111) and Co(311) surfaces

2018 ◽  
Vol 8 (10) ◽  
pp. 2728-2739 ◽  
Author(s):  
Lili Liu ◽  
Mengting Yu ◽  
Qiang Wang ◽  
Bo Hou ◽  
Yan Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Fischer Tropsch ◽  
Functional Theory ◽  
Fischer Tropsch Synthesis ◽  
Structure And Morphology ◽  
Growth Modes ◽  
Ru Promoter ◽  
Insight Into

The adsorption configurations, growth modes and morphology of a Ru promoter under the approximate conditions of cobalt catalyzed Fischer–Tropsch synthesis (FTS) were investigated by density functional theory (DFT) calculations.

On the dissolution of lithium sulfate in water: anion photoelectron spectroscopy and density functional theory calculations

2015 ◽  
Vol 17 (8) ◽  
pp. 5624-5631 ◽  
Author(s):  
Gang Feng ◽  
Gao-Lei Hou ◽  
Hong-Guang Xu ◽  
Zhen Zeng ◽  
Wei-Jun Zheng
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Photoelectron Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Lithium Sulfate ◽  
Functional Theory ◽  
Anion Photoelectron Spectroscopy ◽  
Insight Into

Microscopic insight into the dissolution of Li2SO4in water was gained using photoelectron spectroscopy combined with DFT calculations.

Halodiazoacetates as useful tools for selective halo-functionalization

2011 ◽  
Vol 83 (3) ◽  
pp. 565-575 ◽  
Author(s):  
Hanne Therese Bonge ◽  
Tore Hansen
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Diazo Compounds ◽  
Insertion Reactions ◽  
Functional Theory ◽  
Kinetic Activity ◽  
Synthetic Utility ◽  
Insight Into ◽  
Halocarbonyl Compounds

The halodiazoacetates are a group of synthetically useful halogenated diazo compounds that can be used in Rh(II)-catalyzed carbenoid reactions. In the reactions between the halodiazoacetates and electron-rich, sterically unhindered alkenes, halocyclopropanes are formed in good to excellent yields. The halodiazoacetates also react well in C–H and Si–H insertion reactions, broadening the synthetic utility of these reactions. The products of the reactions are synthetically useful α-halocarbonyl compounds. Density functional theory (DFT) calculations have given insight into the mechanism of the cyclopropanation and C–H insertion reactions of the halodiazoacetates, and have also shown that the halodiazoacetates have a particularly high kinetic activity.

Mechanistic Study of the Cooperative Palladium/Lewis Acid-Catalyzed Transfer Hydrocyanation Reaction: The Origin of the Regioselectivity

2021 ◽  
Author(s):  
Dandan Jiang ◽  
Xiaojun Li ◽  
Jiali Cai ◽  
Yuna Bai ◽  
Lixiong Zhang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Lewis Acid ◽  
Density Functional ◽  
Catalytic Mechanism ◽  
Mechanistic Study ◽  
Functional Theory ◽  
Terminal Alkenes ◽  
Acid Catalyzed ◽  
Insight Into

Density functional theory (DFT) calculations have been performed to gain insight into the catalytic mechanism of the Palladium/Lewis acid-catalyzed transfer hydrocyanation of terminal alkenes to reach the linear alkyl nitrile...

scholarly journals Elucidating the germanium distribution in ITQ-13 zeolites by density functional theory

2021 ◽  
Author(s):  
Michael Fischer ◽  
Carlos Bornes ◽  
Luís Mafra ◽  
João Rocha
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Basal Plane ◽  
Density Functional ◽  
Dynamic Behaviour ◽  
Local Environment ◽  
19F Nmr ◽  
Functional Theory ◽  
Clear Identification

ITQ-13 is a medium-pore zeolite that can be prepared in all-silica form and as silicogermanate with Si/Ge ratios as low as 3. Usually synthesised in the presence of fluoride, ITQ-13 is among the very few systems containing fluoride anions in two distinct cage types, cube-like d4r units and [4·5^6] cages. Here, dispersion-corrected density functional theory (DFT) calculations are used to investigate the energetically most favourable Ge distributions for Si/Ge ratios between 55 and 6. The calculations show Ge atoms are incorporated at both the corners of d4r cages and at the basal plane of the [4·5^6] cages, in accordance with 19F-NMR spectroscopy. Two Ge atoms at adjacent corners of [4·5^6] cages are stable at the highest Ge content. Such a local environment has not yet been considered in the experimental literature. A calculation of the corresponding 19F-NMR resonance points to overlap with other resonances, which might preclude its clear identification. Additional calculations investigate the variation of the dynamic behaviour of the fluoride anions as a function of the local environment as well as the selective defluorination of the [4·5^6] cages.

Mechanistic insight into H2-mediated Ni surface diffusion and deposition to form branched Ni nanocrystals: a theoretical study

2020 ◽  
Vol 22 (41) ◽  
pp. 23869-23877
Author(s):  
Yan Li ◽  
Ning Liu ◽  
Chengna Dai ◽  
Ruinian Xu ◽  
Bin Wu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Ab Initio ◽  
Surface Diffusion ◽  
Density Functional ◽  
Theoretical Study ◽  
Functional Theory ◽  
Mechanistic Insight ◽  
Insight Into

Present work investigates the kinetic role of H2 during Ni surface diffusion and deposition to generate branched Ni nanostructures by employing density functional theory (DFT) calculations and ab initio molecule dynamic (AIMD) simulations.

Mechanistic insights into the rhodium–copper cascade catalyzed dual C–H annulation of indoles

2021 ◽  
Author(s):  
Xiaoqian He ◽  
Lei Zhu ◽  
Dan Heng ◽  
Fenru Liu ◽  
Shihan Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Diazo Compounds ◽  
Functional Theory ◽  
Unsaturated Esters ◽  
Mechanistic Insight ◽  
Insight Into

Density functional theory (DFT) calculations have been performed to provide mechanistic insight into the Rh/Cu co-catalyzed multicomponent annulation of indoles, diazo compounds, and α,β-unsaturated esters.

Theoretical insight into dihydrogen activation with β-diketiminato ligand supported Group 13 and 14 elements: mechanism and activity difference

2021 ◽  
Author(s):  
Weiyi Li ◽  
Cai-Qin Li ◽  
Xiaoyan Zhang ◽  
Chuanxi Xia ◽  
Geng Leng
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Density Functional ◽  
Functional Theory ◽  
Group 13 ◽  
Activity Difference ◽  
Oniom Method ◽  
Theoretical Insight ◽  
Insight Into ◽  
Bimolecular Mechanism

On the basis of density functional theory (DFT) calculations within the framework of the ONIOM method, here we report a new bimolecular mechanism for understating dihydrogen activation using the β-diketiminate...

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