Anthracene, structure

The most abundant aromatics in the mid-distillate fractions are di- and trimethyl naphthalenes. Other one and two ring aromatics are undoubtedly present in small quantities as either naphtheno- or alkyl-homologues in the Cn-C2orange. In addition to these homologues of alkylbenzenes, tetralin, and naphthalene, the mid-distillate contains some fluorene derivatives and phenanthrene derivatives. The phenanthrene structure appears to be favored over that of anthracene structure (Tissot and Welte, 1978 Speight, 1999). 

It is noted that the absorption for the k-k transition of the main chain is significantly stronger for P-1 and P-4 in which the anthracene structure is directly attached to the backbone. Another structural information obtainable from Fig. 4 is that the absorption positions of 71-71 transition of the backbone are significantly blue-shifted when compared with that of unsubstituted PPV whose absorption extends to about 550 nm. This suggests that the presence of bulky substituents partially destruct delocalization of 7t-electrons along the backbone. In other words, coplanarity of the backbone 7t-system must be partially disrupted. 

Figure 27. UV spectra of anthracene and the ring fused bis-anthracene (ref. 2). On the anthracene structure are shown the in-plane orientations of the electric dipole transition moment vectors associated with the intense short wavelength UV bands (1Bb) near 250 nm and the weak long wavelength bands ( LJ near 360 nm. The Xmax for the exciton bands of bis-anthracene are red shifted from the corresponding bands in the parent, as the vectors intersect at >90°.

Methods for the Preparation of Polymers with Covalently Attached Luminescent Markers of the Anthracene Structure... 

It is also important that the optical properties of LM with the anthracene structure do not vary greatly over a wide range of changes in the properties of the medium (pH of solution, solvent nature and structure of polymer units surrounding LM). 

Methods for tte Preparation Polymers with Lumin cent Markers of tire Anthracene Structure at Their Chain Ends... 

At present, methods have been developed permitting the bonding of LM with the anthracene structure to different polymer molecules. The reaction of 9-anthryl-diazomethane (ADM) or its derivatives with the COOH groups of macromolecules is the most convenient method for the attachment of LM (Table 1 LMi, LM2,... 

Stable derivatives of (XVI) which are apparently monomers have been isolated for both P 104) and As 343) if a phenyl group is substituted for hydrogen in the 10-position. Since this report is preliminary, the assignment of the anthracene structure is only tentative. A recent X-ray structural study has shown that arsanthrene is a dimer and not the monomer 178) ... 

Methods for the Preparation (rf Polymos with Luminescent Matfcos of tl Anthracene Structure in tl Main Chain... 

Stein, S.E. Griffith, L.L. Bilhners, R. Chen, R.H. Hydrogen transfer between anthracene structures, J. Phys. Chem., 1986, 90, 517. 

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