scholarly journals Local Disorder in Lithium Imide from Density Functional Simulation and NMR Spectroscopy

2012 ◽  
Vol 116 (35) ◽  
pp. 18577-18583 ◽  
Author(s):  
Marie-Laure Bonnet ◽  
Marcella Iannuzzi ◽  
Daniel Sebastiani ◽  
Jürg Hutter
Keyword(s):  
Nmr Spectroscopy ◽  
Density Functional ◽  
Lithium Imide ◽  
Functional Simulation ◽  
Local Disorder

scholarly journals Experimental and Computational Studies on N-alkylation Reaction of N-Benzoyl 5-(Aminomethyl)Tetrazole

Chemistry ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 704-713
Author(s):  
Younas Aouine ◽  
Aaziz Jmiai ◽  
Anouar Alami ◽  
Abdallah El Asri ◽  
Souad El Issami ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Computational Study ◽  
Benzyl Bromide ◽  
13C Nmr Spectroscopy ◽  
Alkylation Reaction ◽  
Computational Studies ◽  
Functional Theory ◽  
1H And 13C Nmr

The N-alkylation reaction of N-benzoyl 5-(aminomethyl)tetrazole (5-AMT) with benzyl bromide was carried out in the presence of K2CO3 as a base. Two separable regioisomers were obtained, thus their purification led to determine the proportion of each of them, and their structures were attributed essentially based on 1H and 13C NMR spectroscopy in addition to the elemental analysis and MS data. In order to confirm the results obtained at the synthesis level, a computational study was carried out by application of density functional theory (DFT) using the Becke three-parameter hybrid exchange functional and the Lee-Yang-Parr correlation functional (B3LYP).

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.

scholarly journals Functional stability of water wire–carbonyl interactions in an ion channel

2020 ◽  
Vol 117 (22) ◽  
pp. 11908-11915 ◽  
Author(s):  
Joana Paulino ◽  
Myunggi Yi ◽  
Ivan Hung ◽  
Zhehong Gan ◽  
Xiaoling Wang ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Nmr Spectroscopy ◽  
Lipid Bilayers ◽  
Density Functional ◽  
Liquid Crystalline ◽  
Density Functional Theory Calculations ◽  
Bulk Water ◽  
Simple Explanation ◽  
Dynamics Simulations ◽  
Water Hydrogen

Water wires are critical for the functioning of many membrane proteins, as in channels that conduct water, protons, and other ions. Here, in liquid crystalline lipid bilayers under symmetric environmental conditions, the selective hydrogen bonding interactions between eight waters comprising a water wire and a subset of 26 carbonyl oxygens lining the antiparallel dimeric gramicidin A channel are characterized by17O NMR spectroscopy at 35.2 T (or 1,500 MHz for1H) and computational studies. While backbone15N spectra clearly indicate structural symmetry between the two subunits, single site17O labels of the pore-lining carbonyls report two resonances, implying a break in dimer symmetry caused by the selective interactions with the water wire. The17O shifts document selective water hydrogen bonding with carbonyl oxygens that are stable on the millisecond timescale. Such interactions are supported by density functional theory calculations on snapshots taken from molecular dynamics simulations. Water hydrogen bonding in the pore is restricted to just three simultaneous interactions, unlike bulk water environs. The stability of the water wire orientation and its electric dipole leads to opposite charge-dipole interactions for K+ions bound at the two ends of the pore, thereby providing a simple explanation for an ∼20-fold difference in K+affinity between two binding sites that are ∼24 Å apart. The17O NMR spectroscopy reported here represents a breakthrough in high field NMR technology that will have applications throughout molecular biophysics, because of the acute sensitivity of the17O nucleus to its chemical environment.

scholarly journals Conformational Studies of Poly(9,9-dialkylfluorene)s in Solution Using NMR Spectroscopy and Density Functional Theory Calculations

2009 ◽  
Vol 113 (35) ◽  
pp. 11808-11821 ◽  
Author(s):  
Licínia L. G. Justino ◽  
M. Luísa Ramos ◽  
Paulo E. Abreu ◽  
Rui A. Carvalho ◽  
Abilio J. F. N. Sobral ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Conformational Studies

New Hydrazinium Salts of 5,5'-Azotetrazolate

2001 ◽  
Vol 56 (9) ◽  
pp. 857-870 ◽  
Author(s):  
Anton Hammerl ◽  
Gerhard Holl ◽  
M. Kaiser ◽  
Thomas M. Klapötke ◽  
Peter Mayer ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Vibrational Spectroscopy ◽  
Elemental Analysis ◽  
Density Functional ◽  
Nbo Analysis ◽  
Functional Theory ◽  
Explosion Products ◽  
Multinuclear Nmr Spectroscopy ◽  
Guanidinium Azotetrazolate

Abstract Salts of the 5,5′-azotetrazolate dianion with several different hydrazinium cations were pre­ pared. The compounds were characterized by elemental analysis, vibrational spectroscopy (IR, Raman) and multinuclear NMR spectroscopy (1H, 13C, 14 N). The crystal structures of the di-tert-butylhydrazinium, the ethylenedihydrazinium, the diguanidinium and the bis-triamino-guanidinium azotetrazolate were determined. The thermal, shock and friction sensitivities of all compounds were investigated and their explosion products were analysed. For the 5,5′-azotetr-azolate dianion the structure was calculated with density functional theory (B3-LYP). An NBO analysis was performed for the 5,5′-azotetrazolate dianion in order to understand the charge distribution of the dianion.

scholarly journals Investigating the Vanadium Environments in Hydroxylamido V(V) Dipicolinate Complexes Using51V NMR Spectroscopy and Density Functional Theory

2007 ◽  
Vol 46 (22) ◽  
pp. 9285-9293 ◽  
Author(s):  
Kristopher J. Ooms ◽  
Stephanie E. Bolte ◽  
Jason J. Smee ◽  
Bharat Baruah ◽  
Debbie C. Crans ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Nmr Spectroscopy ◽  
Density Functional ◽  
Functional Theory
Sign in / Sign up

Export Citation Format

Share Document