Quantum Mechanical Calculations of NMRJCoupling Values in the Determination of Relative Configuration in Organic Compounds

2004 ◽  
Vol 6 (6) ◽  
pp. 1025-1028 ◽  
Author(s):  
Giuseppe Bifulco ◽  
Carla Bassarello ◽  
Raffaele Riccio ◽  
Luigi Gomez-Paloma
Keyword(s):  
Organic Compounds ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Relative Configuration

Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods

ChemInform ◽  
2007 ◽  
Vol 38 (50) ◽  
Author(s):  
Giuseppe Bifulco ◽  
Paolo Dambruoso ◽  
Luigi Gomez-Paloma ◽  
Raffaele Riccio
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Computational Methods ◽  
Relative Configuration

Determination of Relative Configuration in Organic Compounds by NMR Spectroscopy and Computational Methods

2007 ◽  
Vol 107 (9) ◽  
pp. 3744-3779 ◽  
Author(s):  
Giuseppe Bifulco ◽  
Paolo Dambruoso ◽  
Luigi Gomez-Paloma ◽  
Raffaele Riccio
Keyword(s):  
Nmr Spectroscopy ◽  
Organic Compounds ◽  
Computational Methods ◽  
Relative Configuration

scholarly journals Determination of the electron density in methyl (±)-(1S,2S,3R)-2-methyl-1,3-diphenylcyclopropanecarboxylate using refinements with X-ray scattering factors from wavefunction calculations of the whole molecule

2013 ◽  
Vol 69 (8) ◽  
pp. 910-914 ◽  
Author(s):  
John Bacsa ◽  
John Briones
Keyword(s):  
Electron Density ◽  
Title Compound ◽  
Cyclopropane Ring ◽  
Topological Analysis ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
X Ray ◽  
Compound C ◽  
X Ray Scattering

The molecule of the title compound, C18H18O2, is a substituted cyclopropane ring. The electron density in this molecule has been determined by refining single-crystal X-ray data using scattering factors derived from quantum mechanical calculations. Topological analysis of the electron densities in the three cyclopropane C—C bonds was carried out. The results show the effects of this substitution on these C—C bonds.

scholarly journals Plakilactones G and H from a marine sponge. Stereochemical determination of highly flexible systems by quantitative NMR-derived interproton distances combined with quantum mechanical calculations of 13C chemical shifts

2013 ◽  
Vol 9 ◽  
pp. 2940-2949 ◽  
Author(s):  
Simone Di Micco ◽  
Angela Zampella ◽  
Maria Valeria D’Auria ◽  
Carmen Festa ◽  
Simona De Marino ◽  
...  
Keyword(s):  
Marine Sponge ◽  
Molecular System ◽  
Chemical Shifts ◽  
Integrated Approach ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Chemical Derivatization ◽  
Fiji Islands ◽  
Interproton Distances

In this paper the stereostructural investigation of two new oxygenated polyketides, plakilactones G and H, isolated from the marine sponge Plakinastrella mamillaris collected at Fiji Islands, is reported. The stereostructural studies began on plakilactone H by applying an integrated approach of the NOE-based protocol and quantum mechanical calculations of 13C chemical shifts. In particular, plakilactone H was used as a template to extend the application of NMR-derived interproton distances to a highly flexible molecular system with simultaneous assignment of four non-contiguous stereocenters. Chemical derivatization and quantum mechanical calculations of 13C on plakilactone G along with a plausible biogenetic interconversion between plakilactone G and plakilactone H allowed us to determine the absolute configuration in this two new oxygenated polyketides.

Stable numerical methods for determination of the molecular clusters force fields

2020 ◽  
Vol 28 (5) ◽  
pp. 621-631
Author(s):  
Gulnara M. Kuramshina ◽  
Alexander A. Zakharov
Keyword(s):  
Inverse Problem ◽  
Ab Initio ◽  
Water Clusters ◽  
Force Fields ◽  
Quantum Mechanical ◽  
Quantum Mechanical Calculations ◽  
Small Water ◽  
Molecular Force ◽  
The Given

AbstractThe inverse problem of molecular force fields calculation is considered within the theory of regularization. In our strategy, we choose the stabilizing matrix F^{0} as a result of quantum mechanical calculations. The solution of the inverse problem is finding a matrix 𝐹 which is the nearest by the chosen Euclidean norm to the given ab initio F^{0}. The optimized solution is referred to as regularized quantum mechanical force field (RQMFF). Regularizing algorithms of molecular force fields calculation based on the joint treatment of experimental and ab initio quantum mechanical data have been applied to the calculations of molecular force fields (matrices of force constants) for small water clusters (H2O)𝑛 (n=2,3).

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