Paramagnetic resonance spectra

More P J 1989 Analysis of polarized electron paramagnetic resonance spectra Advanced EPR Applications In Biology and Biochemistry ed A J Hoff (Amsterdam Elsevier) ch 12... 

Closs G L, Forbes M D E and Norris J R 1987 Spin-polarized electron paramagnetic resonance spectra of radical pairs in micelles. Observation of electron spin-spin interactions J. Phys. Chem. 91 3592-9... 

Abragam, A. and Pryce, M.H.L. 1951. Theory of the nuclear hyperfine structure of paramagnetic resonance spectra in crystals. Proceedings of the Royal Society of London A 205 135-153. 

Gaffney, B.J. and McConnell, H.M. 1974. The paramagnetic resonance spectra of spin labels in phospholipid membranes. Journal of Magnetic Resonance 16 1-28. 

Paramagnetic resonance spectra are usually described by the spin Hamilton operator introduced by Abragam and Pryce46 For metal complexes with an effective electron spin S = 1/2, the spin Hamiltonian may be expressed as... 

Tomkiewicz, M.A., Groen, A., and Cocivera, M. Electron paramagnetic resonance spectra of semiquinone intermediates observed during the photooxidation of phenol in water, J. Am. Chem. Soc., 93(25) 7102-7103,1971. 

Fig. 14.5 Electron paramagnetic resonance spectra (EPR) of lepidocrocite at RT, and after stepwise heating to various temperatures (Gehring Hofmeister, 1994 with permission).

Figure 13.19 Affinity chromatography with 2,2,6,6-tetiamethylpiperidine A-oxide (TEMPO)-/ mannose-functionalized dendrimers. Electron paramagnetic resonance spectra for one TEMPO/mannose experiment are shown.

The rates of lateral diffusion of phospholipids in lipid bilayer membranes, and in biological membranes, were first measured using spin-labeled lipids.26 50 10 11 9 In general, these rates have been determined by incorporating spin-labeled lipids such as (V) and (VI) in phospholipid bilayers, or multilayers. The paramagnetic resonance spectra of labels such as (V), as well as the nuclear resonance spectra of other lipids in membranes containing (V), depend on the concentration c of the label in the membrane and the rate of lateral motion of the lipids. Two methods... 

Devaux and McConnell9 took advantage of the fact that in fluid membranes such as egg phosphatidylcholine, the resonance spectra of spin labels such as V and VI depend strongly and monotonically on the label concentration c when c 3= 5 mole %. The normalized paramagnetic resonance spectra S0(H, c) of a series of samples, all of uniform concentration c, were determined experimentally.9 The observed time-dependent spectra are then obtained from the equation... 

Fig. 4. Schematic representation of transient method employed by Devaux and McConnell9 to measure the rates of lateral diffusion of phospholipids in model membranes. The upper diagram represents a concentrated patch of labels at the beginning of the experiment, time f = 0. At later times f>0, the molecules diffuse laterally, as shown in the lower two drawings. The paramagnetic resonance spectra depend on the spin-label concentration in the plane of the membrane, and an analysis of the time dependence of these spectra yielded the diffusion constant. [Reprinted with permission from P. Devaux and H. M. McConnell, J. Am. Chem. Soc., 94, 4475 (1972). Copyright by American Chemical Society.]...

This is a fortunate result, since the paramagnetic resonance spectra of phospholipid spin labels such as (V), (VI), (IX), and (X) are sensitive to their state of aggregation, concentration, and rates of lateral motion. This... 

We assume that the affinities of these specific IgG molecules for spin-labeled lipid haptens such as (V), (IX), or (X) are of the same order of magnitude. Figure 10 illustrates the effect of antibody binding on the paramagnetic resonance spectra of (X) incorporated into lipid membrane vesicles. 

Applications of ligand field theory to many transition metal complexes have played an important role in the interpretation of visihle absorption spectra, magnetism, luminescence, and paramagnetic resonance spectra. 

F. S. Ham, Jahn-Teller effects in electron paramagnetic resonance spectra, in Electron Paramagnetic Resonance, edited by S. Geshwind, Plenum, New York, 1972, pp. 1-119. 

Figure 2. Electron paramagnetic resonance spectra of Mr bound to the single catalytic site on (Na + K )-ATPase. The X-hand spectrum (9.5 GHz) is shown in A, while the K-band spectrum (35 GHz) of the same complex is shown in B. The enzyme-Mn2 complex was centrifuged out of 20mM Tes-TMA, pH 7.5, and then combined with buffer so that the final concentrations were 0.15mM (Ha 4-K )-A TPase, 0.1 mM MnCl, 20mM Tes-TMA, pH 7.5. T = 23°C.

Table III. Electron Paramagnetic Resonance Spectra of Intermediates I-V...

Other peroxygen species can also be photolytically cleaved to yield the hydroxyl radical and another radical centre. For example, homolysis of peroxymonosulfate (HOOSO3) generates OH and SO4-. The concentration of the generated hydroxyl radical can be controlled by variation of the wavelength and the intensity used. The photolysis of hydrogen peroxide in the presence of alcohol produces EPR (electron paramagnetic resonance) spectra which indi-... 

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