The electron spin resonance ESR spectrum

The nitroxide biradical 35 has approximate Z)2 symmetry. The electron spin resonance (ESR) spectrum has been obtained in ethanol and computer simulated in frozen ethanol <1995MRCS129>. 

In the anion-radicals of nitro compounds, an unpaired electron is localized on the nitro group and this localization depends on the nature of the core molecule bearing this nitro substituent. The value of the hyperfine coupling (HFC) constant in the electron-spin resonance (ESR) spectrum reflects the extent of localization of the unpaired electron values of several nitro compounds are given in Table 1.1. 

The electron spin resonance (ESR) spectrum of the radical anion of 1,10-phenanthroline obtained by reduction of 1,10-phenanthroline with sodium has been measured, and hyperfine splitting constants were assigned.116... 

Spin immunoassay is also a type of homogeneous immunoassay. A change in the electron spin resonance (ESR) spectrum of a spin (marker)-labeled... 

The nature and the possible structures of Xj and X2 are indicated by their electronic spectra. The absorption maximum at 425 nm in benzene and the shape of the spectrum of Xl9 the first short-lived intermediate (Figure 15), closely resemble those of the spectrum (A.max at 422 nm in methylene chloride) of TPP Mn(IV) prepared independently (31, 32, 33, 36), possibly indicating a charge-transfer complex (Figure 17). This assumption of a loose side-on complex resulting from a two-electron transfer is consistent with the previous results of the electron spin resonance (ESR) spectrum observed for an oxygencarrying species, TPP Mn(II) or substituted TPP Mn(II) (37). The... 

INDO and McLachlan-modified HMO calculations have been conducted to help interpret the electron spin resonance (ESR) spectrum of cation radical (120) <78JPC1181> which is generated by protonation of (98) in TFA followed by reduction with zinc of the resultant dication (119) (Scheme 1) <63TL95>. The calculated energy level of the HOMO for (120) is of lower energy than that of the isoelectronic fluorene anion radical in both the INDO and HMO approximations. Similar calculations have been conducted to explain the ENDOR spectrum of (120) <84CPL398>. 

The electron spin resonance (ESR) spectrum of humic and fulvic acids consists of a single tine identified by its position and width. In general, the ESR spectra are devoid of hyperfine splitting. The ESR spectra of humic substances contain relatively little data and they result from only a small fraction of the total number of molecules that comprise the humic and fulvic acid. However, ESR yields some information on the nature of free radicals in humic substances. Comparison of the ESR properties among humic fractions reveals that fulvic acids contain greater quantities of free radicals than humic acids. 

While many spectroscopic studies have been published on dimers, the most extensive polymer studies have been with Ag, Na, and Cu clusters. As might be expected much of the interest in silver relates to the photographic process where it appears that a four-atom silver cluster on a silver halide surface leads to reduction by developer, whereas a three-atom cluster does not. The electron spin resonance (ESR) spectrum of sodium in argon confirms that the trimer is covalently bonded and not an equilateral triangle. Ultraviolet photoelectron spectroscopy (UPS) of Cu clusters indicates that the d band is separate from the s band, unlike in the bulk or in the Xa calculations mentioned earlier. 

The shape and width of the electron spin resonance (ESR) spectrum of a spin label or probe is sensitive to the mode and rate of rotation of the radical. Thus, examination of the ESR spectrum of the labelled or probed polymer can yield information on the dynamics and relaxations of the polymer and is therefore complementary to such techniques as mechanical, NMR and dielectric relaxation measurements. 

The catalyst for the styrene polymerization is prepared by the mixing of a compound with MAO. The catalytic activity of Cp Ti(OMe)3 is increased by the mixing time under room temperature, and the intensity of the electron spin resonance (ESR) spectrum (g=1.998) also showed an increase of the trivalent titanium species (Fig. 4.6). The polymerization activity of a titanium catalyst increases with an increase in the molar ratio of MAO to Ti. 

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