Search results
Results from the WOW.Com Content Network
This means that the effects are additive, and a table of "diamagnetic contributions", or Pascal's constants, can be put together. [6] [7] [8] With paramagnetic compounds the observed susceptibility can be adjusted by adding to it the so-called diamagnetic correction, which is the diamagnetic susceptibility calculated with the values from the ...
Groups with extended pi-delocalization have larger diamagnetic corrections compared to related saturated ligands. These correction factors were first described by Paul Pascal in 1910. [2] The values and the method of analysis have been revised several times. [1]
The original model demonstrated an accuracy within 1% of literature values for diamagnetic solutions and within 2% for paramagnetic solids. [5] The device facilitates measurements across solid, liquid, and gaseous forms of a wide spectrum of paramagnetic and diamagnetic materials, typically requiring approximately 250 mg of sample for each ...
Substances where the diamagnetic behaviour is the strongest effect are termed diamagnetic materials, or diamagnets. Diamagnetic materials are those that some people generally think of as non-magnetic , and include water , wood , most organic compounds such as petroleum and some plastics, and many metals including copper , particularly the heavy ...
Magnetic susceptibility indicates whether a material is attracted into or repelled out of a magnetic field. Paramagnetic materials align with the applied field and are attracted to regions of greater magnetic field. Diamagnetic materials are anti-aligned and are pushed away, toward regions of lower magnetic fields.
Electron transfer self-exchange rates can be also determined with the experimental value of line-width and chemical shift. [3] Sharp peaks of diamagnetic compounds can be broadened during the electron transfer with its partner paramagnetic compound (one-electron oxidized species), since paramagnetic compounds exhibit broader peaks at a different chemical shift.
These methods offer errors of 2.5, 1.1, and 0.7 kcal/mol when tested against the G2 test set. The CBS methods were developed by George Petersson and coworkers, and they make extrapolate several single-point energies to the "exact" energy. [20] In comparison, the Gaussian-n methods perform their approximation using additive corrections.
The difference between the chemical shift of a given nucleus in a diamagnetic vs. a paramagnetic environment is called the hyperfine shift.In solution the isotropic hyperfine chemical shift for nickelocene is −255 ppm, which is the difference between the observed shift (ca. −260 ppm) and the shift observed for a diamagnetic analogue ferrocene (ca. 5 ppm).