Anthracene, absorption spectrum substituted

For both cis- and Irans-dianthrylethylenes, the degree of deconjugation, which parallels the degree of deviation from coplanarity of the ethylene and anthracene ir-systems, is borne out in the shape of the electronic absorption spectra. Thus, the long-wavelength absorption of cis-dianthrylethylene 38a is characterized by the fine structure pattern which is typical of the anthracene chromophore, while the bathochromically shifted spectrum of the transisomer 39a is virtually structureless (see Figure 7). Substitution of the ethylene double bond is absorption spectroscopically noticeable for the cis-isomers 38b-f by distortion of the anthracene absorption. The absorption... 

Figure 26. Absorption spectrum of benzanthronyl-substituted anthracene 100 in...

The absorption spectrum at 0° has a maximum at 600 nm. Upon rotation of the direction of the incident polarized light by as much as 90°, the absorption intensity decreases. The anisotropy of the absorption spectra reflects the regular orientation of the photogenerated closed-ring isomers and indicates that the photochromic reaction occurred in the single-crystalline phase. The blue color disappeared by irradiation with visible light a > 480 nm). Anthracene-substituted derivatives also showed photochromic properties (01JPC(A)1741). 

Sigma and Pi Complexes. The cationic species with a delocalized positive charge is assumed to be an intermediate in electrophilic substitutions, Fig. 1. Experimental verification of such a species was first claimed (76) on the basis of a red shift in the electronic absorption spectrum of anthracene, 7, when it was dissolved in sulfuric acid ... 

An IR spectrum has been recorded for the tetrabromoaluminate (vdth an admixture of heptabromodialuminate) of a 10-H-anthracenium ion in the range of90-3100 cm Based on the results of deuteration at 9- and 10-positions and of comparison with the spectra of anthracene, 9- and 10-substituted anthracenes and of an acridi-nium cation, the authors have performed the assignment of the observed absorption bands of the anthracenium ion and of the anions AlBr and Al Brf. The stretching... 

Fig. 34 Left. UV/vis-NIR spectrum of nonacene 70c measured in toluene at RT. Right, the long-wavelength portion of the absorption spectra for silylethyne-substituted acenes from anthracene to heptacene and nonacene 70c. Reprinted with permission from [61], Copyright 2011 John Wiley and Sons...

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