Conjugated absorption spectra

Even in-vivo, careful experimentation using transverse radiation relative to the OS will always exhibit the intrinsic conjugate absorption spectra with a peak near 502 nm. This conjugate spectrum is polarization sensitive. It is maximum when the E-field of the radiation is parallel to the mechanical axis of the individual molecules, generally parallel to the axis of the OS. 

Pyrazole and its 3,5-dimethyl and 3,4,5-trimethyl derivatives combined with two moles of dimethyl acetylenedicarboxylate giving products of similar ultraviolet absorption spectra to the parent pyrazoles. These products [e.g., (69)] do not possess the strong broad absorption at ca. 3.20 /u, characteristic of the bonded N—H group which is present in the parent pyrazoles and are formed by two successive Michael addition reactions. In the case of 3,5-dimethylpyra-zole, the initial fumarate (68) has been isolated and possessed a more conjugated type of absorption spectrum to those of the dipyrazolyl-... 

Figure 9 shows the electronic absorption spectrum of a PTTB film which has undergone extensive but incomplete reaction with bromine in a non-in-situ experiment. The absorption spectrum is that expected for a one-dimensional conjugated polymer. The sharpest absorption edge is at about 1490 nm (o.83 eV) and the absorption maximum is located at 1240 nm (1.0 eV). Thus, this material has a bandgap of about 0.83 eV. Note that two small... 

The pulse radiolysis of ODN conjugated with Py and Ptz showed a transient absorption spectrum with a peak at 470 or 520 nm, assigned to Py+ or Ptz + respectively (Fig. 9). The formation rates of Py+ and Ptz+ obtained for Py-1 and Ptz-1 were almost identical to that of the decay of TIOH+ and no secondary formation was observed. These results indicate that a hole migrates from... 

Jin et al. [487] synthesized and studied the PL and EL properties of polymers 403 and 404 that differ by the position of the alkoxy substituent in the phenyl ring, expecting different distortion of the polymer main chain (and consequently conjugation length) due to different steric factors for para- and ort/zo-substitution (Chart 2.98). The absorption spectrum of the ortho-polymer 403 showed a substantial blue shift of 40 nm compared to para 404 and a decrease in EL turn-on voltage (4.5 and 6.5 V, respectively). Both polymers demonstrated nearly the same PL and EL maxima (Table 2.1). 

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