Absorption dimer

Proposed PSII active site based on X-ray Dimer-of-dimers absorption studies... 

Intensity of dimer absorption band increases with concentration. 

The reduced absorption rate observed in the initial phases at high insulin concentrations is the dimeric absorption rate multiplied by the fraction of insulin on dimeric form. This allows us to determine the equilibrium constant Q 0.06 (ml/IU)2 for the mass balance between dimeric and hexameric insulin in the tissue. 

The physical situation is supported by a comparison of computed bandshapes with the measured conventional dimer absorption, the temperature dependence of which is well described. Figure 23 illustrates the situation with three spectra of a 2 M DMEP solution in CCI4 taken at 260 K (a), 298 K (b), and 343 K (c). The measured data points can be fitted well with the already determined spectral components listed in Table 3. Again, the... 

The photodissociation of the dimers to radicals (see 4.1) is an important photochemical consequence of the through-bond interaction. A photodissociation spectrum for 3-3 is similar to the dimer absorption band as determined by the... 

IR absorptions due to double bond stretching motions (1663 cm and 1655 cm ) change on dimerization. In the dimer, absorption for an isolated double bond appears, and that for a conjugated double bond moves to longer wavelengths. 

Dimer absorption of third harmonic photons shown to 361 be important in determining ionization yields in Xe-Ar and Xe-Kr mixtures... 

Note that, in the monolayer of the viologen thiol at these conditions, the dominant state of the reduced form in the monolayer is the dimer of the viologen radical cation, while the solution spectrum is of the monomer form. The wavelength shift of the ER spectrum in reference to the absorption spectrum is due to the dimer formation. In fact, the ER spectrum matches the dimer absorption spectrum. 

Fig.2a schematically shows the absorption and emission spectra of the monomer. If the shift in the ground state absorption is to the red upon dimerization, as shown in Fig.2b for the dimer geometry depicted in Fig.l, successful RSA may be obtained at wavelength X. In Fig.2b we draw the red shifted ground state dimer absorption (solid line) and, as a dashed curve, we show a dimer excited state absorption which is shifted to the blue of the monomer ground state absorption. At X, a (X ) > a (X ). Thus, the first criterion is met at X. In this case state is lower in energy... 

This nonlinear hydrogen bonded species does not show any dimer absorption both for the C-C stretching (1/4) and the CH3 rocking (1/7) mode. For the next larger clusters n = 3 and n = 4 single peaks are observed which are slightly shifted to the... 

I have not included an early report of a dimer absorption at 381 cm"l. 

C02 solutions at 45°C (178). The ratio of dimer absorption to monomer absorption was found to be a strong function of fluid density, with a clear maximum in the near-critical region. In addition, the dimer formation was observed at benzoic acid mole fractions of as low as 10 this was attributed to significant solute-solute interactions in the dilute supercritical fluid solutions. 

Guthmuller J, Zutterman F, Champagne B (2009) Multimode simulation of dimer absorption spectra from first principles calculations application to the 3,4,9,10-perylenetetracarboxylic diimide dimer. J Chem Phys 131 8... 

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