• Free Radicals
  • With some exceptions, these unpaired electrons make free radicals highly chemically reactive towards other substances, or even towards themselves: their molecules will often spontaneously dimerize or polymerize if they come in contact with each other. (wikipedia.org)
  • spectra
  • Fourier-transform spectroscopy is a measurement technique whereby spectra are collected based on measurements of the coherence of a radiative source, using time-domain or space-domain measurements of the electromagnetic radiation or other type of radiation. (wikipedia.org)
  • Accordingly, the technique of "Fourier-transform spectroscopy" can be used both for measuring emission spectra (for example, the emission spectrum of a star), and absorption spectra (for example, the absorption spectrum of a liquid). (wikipedia.org)
  • ENDOR spectra contain information on the type of nuclei in the vicinity of the unpaired electron (NZ and EZ), on the distances between nuclei and on the spin density distribution (HFS) and on the electric field gradient at the nuclei (Q). The right figure illustrates the energy diagram of the simplest spin system where a is the isotropic hyperfine coupling constant in hertz (Hz). (wikipedia.org)
  • radical
  • In the present work, an in vivo spintrapping technique was used in conjunction with electron spin resonance (ESR) spectroscopy to investigate free radical generation in rats following administration of cadmium chloride (CdCl 2 , 40 µmol/kg) and the spin trapping agent α-(4-pyridyl-1-oxide)- N-tert -butylnitrone (POBN, 1 g/kg). (pubmedcentralcanada.ca)
  • Radical reaction mechanisms use single-headed arrows to depict the movement of single electrons: The homolytic cleavage of the breaking bond is drawn with a 'fish-hook' arrow to distinguish from the usual movement of two electrons depicted by a standard curly arrow. (wikipedia.org)
  • TEMPO is used as a radical marker, as a structural probe for biological systems in conjunction with electron spin resonance spectroscopy, as a reagent in organic synthesis, and as a mediator in controlled radical polymerization. (wikipedia.org)
  • The stability of this radical is attributed to the resonance provided by non-bonding electrons on the nitrogen atom, which form a 2c3e (half-) bond between nitrogen and oxygen as well as Hyperconjugation. (wikipedia.org)
  • atom's
  • At even higher field strength, when the strength of the external field is comparable to the strength of the atom's internal field, electron coupling is disturbed and the spectral lines rearrange. (wikipedia.org)
  • Muonium is usually studied by muon spin rotation, in which the Mu atom's spin precesses in a magnetic field applied transverse to the muon spin direction (since muons are typically produced in a spin-polarized state from the decay of pions), and by avoided level crossing (ALC), which is also called level crossing resonance (LCR). (wikipedia.org)
  • magnetic field
  • The nitroxide spin-label 3-beta-doxyl-5-alpha-cholestane (cholestane) was incorporated into DMPC/DHPC bicelles to report the alignment of bicelles in the static magnetic field. (biomedsearch.com)
  • If the spin-orbit interaction dominates over the effect of the external magnetic field, L → {\displaystyle \scriptstyle {\vec {L}}} and S → {\displaystyle \scriptstyle {\vec {S}}} are not separately conserved, only the total angular momentum J → = L → + S → {\displaystyle \scriptstyle {\vec {J}}={\vec {L}}+{\vec {S}}} is. (wikipedia.org)
  • For the microwave frequency of 9388.2 MHz, the predicted resonance occurs at a magnetic field of about B 0 = h ν / g e μ B {\displaystyle B_{0}=h\nu /g_{e}\mu _{\text{B}}} = 0.3350 teslas = 3350 gausses. (wikipedia.org)
  • displaystyle
  • Therefore, the separation between the lower and the upper state is Δ E = g e μ B B 0 {\displaystyle \Delta E=g_{e}\mu _{\text{B}}B_{0}} for unpaired free electrons. (wikipedia.org)
  • An unpaired electron can move between the two energy levels by either absorbing or emitting a photon of energy h ν {\displaystyle h\nu } such that the resonance condition, h ν = Δ E {\displaystyle h\nu =\Delta E} , is obeyed. (wikipedia.org)
  • spectrum
  • The term Fourier-transform spectroscopy reflects the fact that in all these techniques, a Fourier transform is required to turn the raw data into the actual spectrum, and in many of the cases in optics involving interferometers, is based on the Wiener-Khinchin theorem. (wikipedia.org)
  • One of the most basic tasks in spectroscopy is to characterize the spectrum of a light source: how much light is emitted at each different wavelength. (wikipedia.org)
  • pairs
  • Substituents that can donate electron pairs may stabilize the singlet state by delocalizing the pair into an empty p-orbital. (wikipedia.org)
  • methyl
  • Interdigitation causes a large increase in the order parameter of a fatty acid spin labeled near the terminal methyl, 16-doxylstearate, so that it was similar to that of a fatty acid labeled much closer to the polar head group region, 5-doxylstearate. (biomedsearch.com)
  • total
  • Această detectare de cantități extrem de mici de spini electronici neîmperecheați, adică cu spin total differit de zero, face ca tehnica RES să fie extrem de utilă în studiul radicalilor liberi în chimie, ionilor paramagnetici în chimia fizică, diferitelor efecte biochimice și biofizice în medicină și fiziologie. (wikipedia.org)
  • The report deals with spectroscopy products covering the total market, which includes three main industries: pharmaceutical and biotechnology, food and beverage, and environmental industries. (gii.co.jp)
  • pair
  • For example, if a substituent is able to donate a pair of electrons, most likely carbene will not be electrophilic. (wikipedia.org)
  • study
  • In the present study we have investigated the phase behavior of PC and PG in the presence of glycerol and polymyxin by differential scanning calorimetry and the use of fatty acid spin labels. (biomedsearch.com)
  • A comparative study of the effect of cholesterol on bicelle model membranes using X-band and Q-band EPR spectroscopy. (biomedsearch.com)
  • The primary objectives of the study are as follows: To develop and optimize a renal functional magnetic resonance imaging (MRI) protocol consisting of Diffusion-Weighted Magnetic Resonanc. (bioportfolio.com)
  • However
  • It is, however, debatable whether diaryl carbenes such as the fluorene carbene are true carbenes because the electrons can delocalize to such an extent that they become in fact biradicals. (wikipedia.org)