Absorption overlapping

A with a max at 3800A. The absorption overlap of the nitrocompds is plainly evident. The position and slope of each curve in Fig 1 can be qualitatively correlated with the absorption range and % transmittance at the peak for each compd. Nitro me thane, which absorbs more at shorter wave lengths and exhibits the least overlap of the toluene-PPO emission spectrum, accordingly has the least effect on the count Tate of the pure scintiliator... 

The ratio of the isomeric amino ketones in the crude product can be determined from the relative intensities of the signals for the (CH3)2C grouping in a proton magnetic resonance spectrum taken in trifluoroacetic acid (see Note 10). In chloroform-d these absorptions overlap. 

Spectral subtraction usually provides a sensitive method for detecting small changes in the sample. Figure 5 shows the difference spectra between the atactic poly(a,a-dimethylbenzyl methacrylate) s unexposed and exposed to electron-beam at several doses. The positive absorption at 1729 cm-1 is due to the ester carbonyl group consumed on the exposure and the negative ones at 1700 and 1760 cm-1 to the acid and acid anhydride carbonyl groups formed, respectively. The formation of methacrylic acid units was more easily detected using the difference spectrum However, these difference spectra could not be used for the quantitative determination because the absorptions overlap somewhat. 

Figure 4 and Table 1 compare the IR spectra of ammonium bicarbonate and ammonium carbamate in fluorolube mulls. The spectrum for ammonium bicarbonate has absorptions due to the ammonium ion plus absorptions due to bicarbonate anion. The bicarbonate absorptions are similar to those observed for sodium bicarbonate but the absorptions are shifted a little. Although the ammonium and OH absorptions overlap somewhat, the OH peak at 2569-2540 cm-1 is clearly separated from the ammonium absorption region and... 

Suggest a structure for the compound with the formula C5Hl0O2 that has the following IR and l l-NMR spectra. (Some absorptions overlap in the NMR spectrum.)... 

The role of cations in the pulse radiolysis of styrene and a-methyl-styrene is not yet clear. Using frozen glasses, Shida and Hamill (26) and Williams (27) have seen absorptions with peaks at 350 and 650 m/x for styrene and a-methylstyrene. Bands have also been seen previously (24) at 460 or 475 m/x. Perhaps the species responsible for the shoulders seen by Schneider and Swallow between 340 and 370 m/x is a cation, whose absorption overlaps that of the anion radical. This could explain the diminution of the absorption intensity round 390 m/x when n-butylamine was added. However, there was no evidence for an absorption band at longer wavelengths. 

For example, Bosomworth and Gush have measured induced absorption in Hs, Ns, and Oj, confirming with improved precision measurements on Na made by Gebbie and his co-workers. Poll had used these to find a quadrupole moment for Na in good agreement with a wave-mechanical estimate, suggesting that quadrupole induction in fact predominates for Na. The measurements on Oa, on the other hand, show a very broad absorption in spite of a low molecular quadrupole moment, implying dominance of overlap effects in this case. For both Na and Oa, rotation and translation absorptions overlap entirely, but in Ha at 77 K rotation is well separated from the weak, low-frequency translation-absoj ition band. 

The sulfonyl radical CHjSOO also reacts with carotenoids to generate both the cation radical and some pre-cation radical intermediate species (Everett et al, 1996 Mortensen et al., 1997). In the recent study the loss of the ground state absorption led to complex kinetics and these results seem best interpreted by considering that an intermediate (possibly an ion pair) leads to the carotene radical and the adduct [CAR—RSOj] , which has absorption overlapping that of CAR, then undergoes a bimolecular process to give some unidentified product(s). 

Calculate the emission-absorption overlap integral (7) for A and B. (Be sure to give the units.)... 

Thus the birefringence of the liquid crystal is much more critical in the fluorescence polarization studies. Measurements of the order parameter of excited molecules are possible if the rotational relaxation time of the solute is small compared with the lifetime of the emitting state. The birefringence of the liquid crystal is also of critical importance if one wishes to determine the solvent order from the absorption polarization spectrum of the solvent in its nematic phase. The complications arise from the strong refractive index dispersion in the wavelength regions of the solvent absorption bands. Saupe and Maier [104] have treated this case. The same difficulties arise of course if the solute and the solvent absorption overlap. 

There are two other possible mechanisms of energy transfer. When excimer formation and dissociation to the excited monomer are fast and efficient, the partner can carry away the excitation energy. The second process, called trivial energy transfer, is based upon reabsorption of donor emission by an acceptor. The condition of emission-absorption overlap is identical with that for the Forster mechanism. Although this mechanism is uninteresting and trivial from a mechanistic point of view. 

Rotational transitions in a spectrum will follow along a particular K manifold of rotational energy levels however, at a given temperature a system of molecules may occupy more than one K level. As can be seen in Figure 7-2, since the various rotational states in a particular K manifold are close to rotational states in other K manifolds, the rotational spectrum can be expected to be very compheated with possible absorptions overlapping even in highly resolved spectra. 

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