Gauge invariant atomic orbital-density functional theory prediction of accurate gas phase 1H and 13C NMR chemical shifts

2011 ◽  
Vol 38A (6) ◽  
pp. 269-279 ◽  
Author(s):  
Hossein Pasha Ebrahimi ◽  
Hoora Shaghaghi ◽  
Mohsen Tafazzoli
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
13C Nmr ◽  
Density Functional ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Functional Theory ◽  
Gauge Invariant ◽  
1H And 13C Nmr ◽  
Orbital Density

scholarly journals Structural and spectroscopic characterization and DFT studies of 2-amino-1,10-phenanthrolin-1-ium chloride

2019 ◽  
Vol 10 (2) ◽  
pp. 95-101
Author(s):  
Sebile Işık Büyükekşi ◽  
Namık Özdemir ◽  
Abdurrahman Şengül
Keyword(s):  
Density Functional Theory ◽  
Electronic Absorption ◽  
13C Nmr ◽  
Density Functional ◽  
Electronic Absorption Spectra ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Basis Set ◽  
Functional Theory ◽  
1H And 13C Nmr

A versatile synthetic building block, 2-amino-1,10-phenanthrolin-1-ium chloride (L∙HCl) was synthesized and characterized by IR, 1H and 13C NMR DEPT analysis, UV/Vis and single-crystal X-ray diffraction technique. The molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO), 1H and 13C NMR chemical shifts values of the title compound in the ground state were obtained by using density functional theory (DFT/B3LYP) method with 6-311++G(d,p) basis set and compared with the experimental data. Electronic absorption spectrum of the salt was determined using the time-dependent density functional theory (TD-DFT) method at the same level. In the NMR and electronic absorption spectra calculations, the effect of solvent on the theoretical parameters was included using the default model with DMSO as solvent. The obtained theoretical parameters agree well with the experimental findings.

scholarly journals Density functional theory: 1H and 13C-NMR spectra of some coumarin derivatives

2014 ◽  
Vol 79 (11) ◽  
pp. 1405-1411 ◽  
Author(s):  
Selma Spirtovic-Halilovic ◽  
Mirsada Salihovic ◽  
Snezana Trifunovic ◽  
Suncica Roca ◽  
Elma Veljovic ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
13C Nmr ◽  
Density Functional ◽  
Nmr Spectra ◽  
Chemical Shifts ◽  
13C Nmr Spectra ◽  
Coumarin Derivatives ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
Isotropic Chemical Shifts

For some synthesized coumarin derivatives, 1H and 13C NMR isotropic chemical shifts and some other molecular properties were calculated using density functional theory. The calculations yield reliable results, that are in good correlation with experimental data. This is a good basis for the collaboration between experimentalists and quantum chemists.

Density functional theory investigation of the stereochemistry effects on 1H and 13C NMR chemical shifts of poly(vinyl chloride) oligomers

2005 ◽  
Vol 411 (1-3) ◽  
pp. 207-213 ◽  
Author(s):  
Philippe d’Antuono ◽  
Edith Botek ◽  
Benoît Champagne ◽  
Joris Wieme ◽  
Marie-Françoise Reyniers ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Vinyl Chloride ◽  
13C Nmr ◽  
Density Functional ◽  
Chemical Shifts ◽  
Functional Theory ◽  
1H And 13C Nmr ◽  
Nmr Chemical Shifts ◽  
13C Nmr Chemical Shifts ◽  
Poly Vinyl Chloride

Systematic Gauge-Including Atomic Orbital-Hybrid Density Functional Theory Linear Regressions for 13C NMR Chemical Shifts Calculation

2020 ◽  
Vol 12 (3) ◽  
pp. 364-370
Author(s):  
Sara Sâmitha Souza ◽  
Mariana Aparecida de Souza Martins ◽  
Antonio Maia de Jesus Chaves Neto ◽  
Gunar Vingre Da Silva Mota ◽  
Fabio Luiz Paranhos Costa
Keyword(s):  
Density Functional Theory ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Density Functional ◽  
Chemical Shifts ◽  
Atomic Orbital ◽  
Basis Set ◽  
Functional Theory ◽  
Linear Regressions ◽  
Nuclear Magnetic

Density-functional theory calculations of the magnetic shielding for nuclear magnetic resonance provide an important contribution to understand the experimental values obtained in laboratory for chemical shifts present in the samples. From of a comparative of the performance of ten hybrid functional within of the framework of the density-functional theory using 10 different hybrid functionals with 3-21G (B1), 6-31G(d) (B2) and 6-31+ G(d, p) (B3) basis set, with intuit of evaluating of performance of the 13 C nuclear magnetic resonance from a representative of the terpene class and a heterocyclic compound, (–)-loliolide ((7aR)-6-hydroxy-4,4,7a-trimethyl-6,7-dihydro-5H1-benzofuran-2-one). This molecule, satisfactorily, represents the main structure of this class, with conformational freedom, optical activity and a benzofuran nucleus. The ωB97X-D, MPW1K and HSEH1PBE functionals presented the best calculation performance. It is interesting to note that after the use of linear regressions all root mean square error values for ωB97X-D were lower than 3 ppm. These are 2.91 ppm (B1), 2.46 (B2) ppm and 2.62 ppm (B3). The information contained in this work can be used for the assignment of experimental nuclear magnetic resonance spectra and will motivate further studies involving the theoretical calculation of the chemical shift of 13C.

scholarly journals Synthesis Single Crystal X-ray Structure DFT Studies and Hirshfeld Analysis of New Benzylsulfanyl-Triazolyl-Indole Scaffold

Crystals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 685 ◽  
Author(s):  
Ahmed T. A. Boraei ◽  
Saied M. Soliman ◽  
Sammer Yousuf ◽  
Assem Barakat
Keyword(s):  
Density Functional Theory ◽  
Dft Calculations ◽  
Single Crystal ◽  
13C Nmr ◽  
Density Functional ◽  
Chemical Shifts ◽  
Functional Theory ◽  
X Ray ◽  
Reactivity Descriptors ◽  
Hirshfeld Analysis

Benzylsulfanyl-triazolyl-indole scaffold was synthesized through coupling of 4-amino-5-(1H-indol-2-yl)-1,2,4-triazol-3(2H)-thione and benzyl bromide in EtOH under basic conditions (K2CO3). The benzylation direction was deduced from the 13C NMR signal found at 35.09 ppm, assigned for the methylene carbon of the benzyl group, this value indicates that the benzyl group attacks sulfur, not nitrogen. 1H NMR, 13C NMR, COSY, HMQC, HRMS and X-ray single crystal diffraction analysis were used for structure assignment. The desired compound accomplished in good yield. Hirshfeld analysis revealed the importance of the short N...H (1.994–2.595 Ǻ), S…H (2.282 Ǻ) and C…H (2.670 Ǻ) contacts as well as the weak π-π stacking interactions in the molecular packing of benzylthio-triazolyl-indole scaffold. Its electronic and structural aspects were predicted using density functional theory (DFT) calculations and the reactivity descriptors as well. The Uv-Vis spectral bands were assigned based on the time-dependant density functional theory TD-DFT calculations, while the gauge-including atomic orbitals (GIAO) method was used to predict the 1H and 13C NMR chemical shifts.

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