Spectra line

The tliree-line spectrum with a 15.6 G hyperfine reflects the interaction of the TEMPO radical with tire nitrogen nucleus (/ = 1) the benzophenone triplet caimot be observed because of its short relaxation times. The spectrum shows strong net emission with weak E/A multiplet polarization. Quantitative analysis of the spectrum was shown to match a theoretical model which described the size of the polarizations and their dependence on diffrision. 

The molecular structures were rendered with good-quality shading on a blue background. Isosurfaces produced from cube files or checkpoint files also looked nice. Molecular vibrations can be animated on screen and vibrational displacement vectors displayed. The vibrational line spectrum may be displayed too, but the user has no control over the axes. There is no way to set the background color. The display can be saved using several image file formats. 

P.D. Horn and Y.M. Gupta, Luminescence R-Line Spectrum of Ruby Crystals Shocked to 125 kbar along the Crystal c-Axis, Phys. Rev. B 39, 973-979 (1989). 

The EPR spectrum of the ethyl radical presented in Fig. 12.2b is readily interpreted, and the results are relevant to the distribution of unpaired electron density in the molecule. The 12-line spectrum is a triplet of quartets resulting from unequal coupling of the electron spin to the a and P protons. The two coupling constants are = 22.38 G and Op — 26.87 G and imply extensive delocalization of spin density through the a bonds Note that EPR spectra, unlike NMR and IR spectra, are displayed as the derivative of absorption rather than as absorption. 

Linien-spanntmg, /. (Elec.) line tension, line voltage, -spektnun, n. line spectrum, -vcr-sohiebung, /. displacement of lines, -zahl, /. number of lines, -zug, m. line, trace (in a graph). 

Mehrheit,/. majority plurality multiplicity, mehr-kantig, a. many-sided, -kemig, a. polynuclear, having more than one nucleus. Mehr-korperproblem, n. niany-body problem, -kristall, m. polycryatal. -linienspektrum, n. many-line spectrum, mehr-malig, a. repeated, -mals, adv. several times, repeatedly. 

Vielling, m. Cryat.) multiple twin. Viellinienspektrum, n. many-line spectrum, viellinig, a. many-line, multilinear, viel-mal, adv. many times, -mehr, adv. much more, more. — conj. rather, -phasig, a. polyphase, multiphase, -polig, a. multipolar. 

Fig. 15-2. Contrast between the continuous spectrum of a hot tungsten ribbon and the line spectrum of a hydrogen discharge tube.

To explain why hydrogen atoms emit the line spectrum, we must seek a model with the... 

Since an atom of a given element gives rise to a definite, characteristic line spectrum, it follows that there are different excitation states associated with different elements. The consequent emission spectra involve not only transitions from excited states to the ground state, e.g. E3 to E0, E2 to E0 (indicated by the full lines in Fig. 21.2), but also transisions such as E3 to E2, E3 to 1( etc. (indicated by the broken lines). Thus it follows that the emission spectrum of a given element may be quite complex. In theory it is also possible for absorption of radiation by already excited states to occur, e.g. E, to 2, E2 to E3, etc., but in practice the ratio of excited to ground state atoms is extremely small,... 

Products of decomposition may be of such small particle size that superparamagnetism is exhibited [329] (e.g. by Fe203 [324,326] where the characteristic six-line spectrum of antiferromagnetic Fe203 is replaced by a doublet with an isomeric shift corresponding to Fe3+). 

Four dichloro isomers, the 1,6-, 2,3-, 2,7-, and 2,8-dichlorodibenzo-p-dioxins, were studied. These compounds also dissolve in TFMS acid, forming cation radicals in the absence of oxidizing agents or UV irradiation. The 2,8-isomer (Figure 5) exhibited a three-line spectrum, in agreement with the two equivalent protons in the 3,6 positions. The 2,7-isomer should also exhibit a three-line spectrum, similar to the 2,8-... 

Fig. 1. Absorption and photoluminescence dashed line) spectra of a thin film of LPPP 26 and electroluminescence solid line) spectrum of an ITO / LPPP 26 (60 nm) / A1 device (from [50])...

The isomer shift, d, arises from the Coulomb interaction between the positively charged nucleus and the negatively charged s-electrons, and is thus a measure for the s-electron density at the nucleus, yielding useful information on the oxidation state of the iron in the absorber. An example of a single line spectrum is fee iron, as in stainless steel or in many alloys with noble metals. 

Very thick absorbers may be required for applied-field measurements to achieve reasonable absorption depths and measuring times because the Mossbauer spectra are usually split into several hyperfine components. Here the iron content may be as large as 100 pg Fe per cm (1.75 pmol Fe per cm ), which would correspond to t 1 for a two-line spectrum. For smdies of frozen solutions, Fe concentrations of 1 mM are desirable for each nonequivalent iron site [35]. 

The broadened single-line spectrum of the early measurements by Cohen et al. [176], obtained with a TaC absorber and an annealed W/W metal source at room temperature, was assigned by the authors to the 3/2 <-> 3/2 transition with an estimated QJQg ratio between 0.8 and 0.95. 

Less than the natural line width materials are magnetic and exhibit a six-line spectrum at low... 

Name from the indigo-colored bands in the line spectrum makes flames blue violet... 

Figure 3.4 shows (i) a line spectrum (one-dimensional dispersive spec-trographic record), (ii) a spectrometric record, (iii) an interferogram obtained by a Fourier transform spectrometer, and (iv, v) two- and three-dimensional double dispersive spectra recorded e.g. by Echelle spectrometers. In principle, all forms may be obtained by OES. 

In the solid, dynamics occurring within the kHz frequency scale can be examined by line-shape analysis of 2H or 13C (or 15N) NMR spectra by respective quadrupolar and CSA interactions, isotropic peaks16,59-62 or dipolar couplings based on dipolar chemical shift correlation experiments.63-65 In the former, tyrosine or phenylalanine dynamics of Leu-enkephalin are examined at frequencies of 103-104 Hz by 2H NMR of deuterated samples and at 1.3 x 102 Hz by 13C CPMAS, respectively.60-62 In the latter, dipolar interactions between the 1H-1H and 1H-13C (or 3H-15N) pairs are determined by a 2D-MAS SLF technique such as wide-line separation (WISE)63 and dipolar chemical shift separation (DIP-SHIFT)64,65 or Lee-Goldburg CP (LGCP) NMR,66 respectively. In the WISE experiment, the XH wide-line spectrum of the blend polymers consists of a rather featureless superposition of components with different dipolar widths which can be separated in the second frequency dimension and related to structural units according to their 13C chemical shifts.63... 

Now consider a concrete example. Suppose we have a nitroxide biradical with aN = 13 G. In the strong exchange limit, we expect a five-line spectrum with a spacing of 6.5 G and the usual 1 2 3 2 1 intensity ratios for two equivalent spin-1 nuclei. In the weak exchange limit, we expect a three-line spectrum with a spacing of 13 G and intensity ratios 1 1 1. In intermediate cases, up to 15 lines are expected, as shown in Figure 6.1. 

Because the d5 configuration is spherically symmetric, high-spin Mn(ii) and Fe(m) usually have nearly isotropic -matrices and Mn(ii) usually has a nearly isotropic -matrix. This means that there usually is not much information in the ESR spectrum of these high-spin species. Indeed, high-spin Mn(n) is usually an unwanted interference for those interested in low-spin Mn(n) the ESR spectrum is very characteristic with six hyperfine lines with a coupling constant of 80-100 G. Because the g- and -matrices are nearly isotropic, the six-line spectrum persists in frozen solutions. 

The photodecomposition of isopropyl alcohol on silica gel produces a seven-line spectrum having a hyperfine separation of 20.7 G and an amplitude ratio of 1 6.7 20.2 31 21.1 7.4 1.5 (68). This spectrum was attributed to SiOCMe2 formed from the ether surface groups. In addition to this spectrum the spectrum of the methyl radical was also observed. Irradiation of adsorbed tert-butyl alcohol produced a three-line spectrum which was attributed to SiOMe2OCH2 (68). Apparently the splitting from the methyl protons was too small to be observed. 

A variety of radical ions have been produced by photochemical reactions involving adsorbed species. One of the simplest of these is the radical ion which is formed upon y irradiation of ethylene adsorbed on silica gel (92). The resulting nine-line spectrum has been attributed to (CH2 = CHi-) + however, it may be due to the corresponding negative ion. The neutral ethyl radical is also formed under these conditions. 

The radical cation of benzene has been produced by y irradiation of benzene adsorbed on silica gel (62, 63). The seven-line spectrum shown in Fig. 24 is expected for a molecule having six equivalent protons. An experimental coupling constant of 4.4 G, compared to a value of 3.75 G for the negative ion, gives strong support for attributing the spectrum to a positive ion. The g value is also consistent with this assignment. 

A five-line spectrum attributed to the NH2 radical has been observed by Sorokin and co-workers (105) in y-irradiated zeolites containing am-... 

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