Electron continued spin resonance spectroscopy

Jee B, Eisinger K, Gul-E-Noor F et al (2010) Continuous wave and pulsed electron spin resonance spectroscopy of paramagnetic framework cupric ion in the Zn(Il) doped porous coordination polymer Cu3 xZnx(btc)2. J Phys Chem C 114 16630-16639... 

Grupp A and Mehring M 1990 Pulsed ENDOR spectroscopy in solids Modern Pulsed and Continuous-Wave Electron Spin Resonance ed L Kevan and M K Bowman (New York Wiley) ch 4, pp 195-229... 

Various optical detection methods have been used to measure pH in vivo. Fluorescence ratio imaging microscopy using an inverted microscope was used to determine intracellular pH in tumor cells [5], NMR spectroscopy was used to continuously monitor temperature-induced pH changes in fish to study the role of intracellular pH in the maintenance of protein function [27], Additionally, NMR spectroscopy was used to map in-vivo extracellular pH in rat brain gliomas [3], Electron spin resonance (ESR), which is operated at a lower resonance, has been adapted for in-vivo pH measurements because it provides a sufficient RF penetration for deep body organs [28], The non-destructive determination of tissue pH using near-infrared diffuse reflectance spectroscopy (NIRS) has been employed for pH measurements in the muscle during... 

Electron-nuclear double resonance (ENDOR) spectroscopy A magnetic resonance spectroscopic technique for the determination of hyperfine interactions between electrons and nuclear spins. There are two principal techniques. In continuous-wave ENDOR the intensity of an electron paramagnetic resonance signal, partially saturated with microwave power, is measured as radio frequency is applied. In pulsed ENDOR the radio frequency is applied as pulses and the EPR signal is detected as a spin-echo. In each case an enhancement of the EPR signal is observed when the radiofrequency is in resonance with the coupled nuclei. 

Electron paramagnetic resonance spectroscopy, also known as electron spin resonance (ESR) spectroscopy, detects the excitation of electron spins in an applied external magnetic field.13 Conventional continuous-wave (CW) EPR is based on resonance of a fixed-frequency standing microwave to excite some of the electrons in Zeeman-split spin multiplets to undergo a transition from a lower Ms level to a higher... 

Studying RNA Using Site-Directed Spin-Labeling and Continuous-Wave Electron Paramagnetic Resonance Spectroscopy... 

The properties are most useful when there are several closely overlapping peaks, and higher order derivatives are commonly employed, for example in electron spin resonance and electronic absorption spectroscopy, to improve resolution. Figure 3.11 illustrates the first and second derivatives of two closely overlapping peaks. The second derivative clearly indicates two peaks and fairly accurately pinpoints their positions. The appearance of the first derivative would suggest that the peak is not pure but, in this case, probably does not provide definitive evidence. It is, of course, possible to continue and calculate the third, fourth, etc., derivatives. 

The AAS method has several limitations. For the trace elements, particularly the colorants cobalt and nickel, the dilution factor required for analyses of 12 elements by continuous nebulization places these elements close to the detection limits for flame AAS. More accurate data on these and other trace elements are necessary before conclusions can be drawn on the source minerals used to impart color. Phosphorus, a ubiquitous minor component of medieval stained glass, has not been determined by AAS in the course of this work, but has the potential to provide key information on sources of plant ash. A full understanding of the colorant role of the transition metal elements is not possible on the basis of analysis alone UV-visible spectroscopy, electron spin resonance spectrometry, and Mossbauer spectroscopy, for example, are necessary adjuncts to achieve this aim. The results of the application of these techniques and the extension of the AAS method to trace element determination by pulse nebulization and furnace atomization will be addressed in future reports. 

Before 1965, that is in the Hinshelwood era, the stresses were on bulk gas kinetics and spectroscopy and there was additionally the work of Bell on solution reaction kinetics. There was little or no study of either condensed phases or of biological systems. The most noticeable development in the subsequent period was an effort at a much more detailed understanding of how individual molecules react, a continuation of previous work but a much deeper analysis, part of it theoretical chemistry. This requires an intensive exploration of energy distribution in the different bonds of a molecule. Some of the work applied to molecular interactions with surfaces. There was also a diversification to the use of new spectroscopic techniques including photo-electron spectroscopy by D.W. Turner (1968, professor 1985), and C.J. Danby and J.H.D. Eland (1983) (see also J.C. Green and A.F. Orchard in the Inorganic Chemistry Laboratory), electron spin resonance by K.A. McLauchlan (1965), who developed the experimental method while he collaborated with P.W. Atkins... 

Electron spin resonance (ESR) spectroscopy is a very powerful and sensitive method for the characterization of the electronic structures of materials with unpaired electrons. There is a variety of ESR techniques, each with its own advantages. In continuous wave ESR (CW-ESR), the sample is subjected to a continuous beam of microwave irradiation of fixed frequency and the magnetic field is swept. Different microwave frequencies may be used and they are denoted as S-band (3.5 GHz),X-band (9.25 GHz), K-band (20 GHz), Q-band (35 GHz) and W-band (95 GHz). Other techniques, such as electron nuclear double resonance (ENDOR) and electron spin echo envelope modulation (ESEEM) spectroscopies, record in essence the NMR spectra of paramagnetic species. 

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