Vinyl anthracene

The properties are very sensitive to composition and the charge carriers are apparently positive. Other studies have shown poly(acenaph-thalene) to be only slightly photo-conductive while the nitrated polymer exhibits a photocurrent dependent upon the degree of nitration (100). Since the number of mobile n electrons is the same as in poly (vinyl naphthalene), the authors conclude that some form of stereoregularity is required for enhanced conductivity. Complexes of poly(vinyl anthracene) with halogen molecules show enhanced conductivity and reduced activation energy which is thought to be typical of an electronic semiconductor (101). 

The cationic polymerization of 9-vinyl anthracene (101) was originally reported to proceed by 1,2-chain growth to produce a substituted vinyl-type polymer [49]. However it was later shown that the actual structure obtained was poly-9,10-dimethyleneanthracene (105) [45]. This polymer was obtained by the sequence of reactions shown in Fig. 16 [45,50],... 

Figure 16 Formation of poly-9,10-dimethyleneanthracene by the cationic polymerization of 9-vinyl anthracene. (From Ref. 45.)...

As regards the profile of the potential energy surface, the behavior of deuterated vinyl anthracene (] ) provided valuable informations (26), On benzil sensitized irradiation, its E-isomer... 

In benzene the time-resolved fluorescence spectra of 2-vinylanthracene show one-way rotation from a rotamer showing shorter-wavelength fluorescence to another with longer-wavelength fluorescence [136] similar to 11. Substitution of a t-butyl and methyl group on the terminal carbon of 2-vinyl-anthracene, that is, trans-6 and 6b, leads to similar internal rotations in the excited singlet state. The activation energies and the frequency factors for the internal rotation are 3.9, 4.3, and 4.3 kcal mol and 1.7, 1.8, and 1.8 x 10" s , for 2-vinylanthracene, 6a, and 6b, respectively. 

A purely thermal homopolymerization to high molar masses has only been proved for styrene and some of its derivatives, as well as for 2-vinyl pyridine, 2-vinyl furan, 2-vinyl thiophene, methyl methacrylate, and acenaphthylene. In contrast, vinyl mesitylene, 9-vinyl anthracene, and methyl acrylate do not polymerize spontaneously. Some of fhe thermal polymerizations proceed by a free radical mechanism others, however, do not. 

A comparison of the copolymerization reactivities of various vinyl anthracenes with those of the corresponding naphthalene and benzene derivatives based on experimental results and Hiickel calculations of the stabilization enei es led to the conclusion that steric factors governed the polynjerizability of the vinyl anthracenes,... 

Anthracene is one of the most thoroughly studied photoconductors, and numerous attempts have been made to synthesize high-molecular-weight materials or polymers containing similar groups. Poly(9-vinyl-anthracene) [66], poly(l-vinylanthracene) and poly(2-vinylanthracene)... 

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