The Conformations of 1-Thiacyclooctan-3-One Dynamic Nuclear Magnetic Resonance and Force-Field Calculation
Authors
Abstract:
The 1H and natural-abundance 13C-NMR spectra of 1-thiacyclooctan-3-one (1) have been measured from 25 to -100°C. Coalescence is observed in the 1H-NMR spectra of (1) at about -80°C, and attributed to ring inversion in a boat-chair conformation, which is the predominant conformation of (1). The free energy of activation (DG¹) for this process is 9.2±0.2 kcal/mol. The 13C-NMR spectra of (1) is temperature independent.
similar resources
the conformations of 1-thiacyclooctan-3-one dynamic nuclear magnetic resonance and force-field calculation
the 1h and natural-abundance 13c-nmr spectra of 1-thiacyclooctan-3-one (1) have been measured from 25 to -100°c. coalescence is observed in the 1h-nmr spectra of (1) at about -80°c, and attributed to ring inversion in a boat-chair conformation, which is the predominant conformation of (1). the free energy of activation (dg¹) for this process is 9.2±0.2 kcal/mol. the 13c-nmr spectra of (1) is te...
full textForce-detected Nuclear Magnetic Resonance
The drive to improve the sensitivity of nuclear magnetic resonance (NMR) to smaller and smaller sample volumes has led to the development of a variety of techniques distinct from conventional inductive detection. In this chapter, we focus on the technique of force-detected NMR as one of the most successful in yielding sensitivity improvements. We review the rationale for the technique, its basi...
full textDynamic nuclear polarization in a magnetic resonance force microscope experiment.
We report achieving enhanced nuclear magnetization in a magnetic resonance force microscope experiment at 0.6 tesla and 4.2 kelvin using the dynamic nuclear polarization (DNP) effect. In our experiments a microwire coplanar waveguide delivered radiowaves to excite nuclear spins and microwaves to excite electron spins in a 250 nm thick nitroxide-doped polystyrene sample. Both electron and proton...
full textNUCLEAR MAGNETIC RESONANCE STUDY OF THE STRUCTURE OF GLYOXALDIHYDRAZONE
Study of the nuclear magnetic resonance spectra of glyoxaldihydrazone in dimethylsulfoxide and deuterochlorofonn leads to the conclusion that this compound exists predominantly in non-chelate structure
full textIterative Force-Field Calculation and Molecular Dynamics of Cyclooctanone
Body's iterative force-field computer program has been used to calculate strain energies in cyclooctanone (I). 348 MHZ 1H NMR spectra of (I) have been investigated over the temperature range of 25° to -160°C. Two conformation processes affect the 1H NMR spectrum of (I). Iterative force-field calculations on the conformations and conformational interconversion paths of ...
full textZero-Field Nuclear Magnetic Resonance
Techniques for studying molecular structure, such as x-ray diffraction and nuclear magnetic resonance (NMR), often require the use of single crystals' or oriented samples. ' NMR, for example, is sensitive to interatomic distances and angles through spectral splittings caused by internucl. ear dipol. e-dipole couplings in high magnetic field. Where only polycrystalline powders or amorphous mater...
full textMy Resources
Journal title
volume 14 issue 1
pages 49- 54
publication date 1995-03-01
By following a journal you will be notified via email when a new issue of this journal is published.
Hosted on Doprax cloud platform doprax.com
copyright © 2015-2023