Poly-/3-vinylnaphthalene

Results are shown in Figure 5. Samples of PVCa were doped with 10% by weight of poly(1-vinylnaphthalene) to determine if the naphthalene chromophore would serve as a quencher for the surface oxidation of PVCa as it appears to do in the case of fluid solutions. 

Examples of the two macromolecular nomenclature systems are as follows. For source-based names for homopolymers and copolymers polyacrylonitrile, poly(mcthyl methacrylate), polylacrylamidc-co-vinylpynolidinone), polybutadiene-felocJ-polystyrene, and poly(propyl methacrylate)-gra/t-poly( 1-vinylnaphthalene). Structure-based examples arc as follows polyloxy-l,4-phcnylcnct (1), po]y(oxycthyl-cncoxytcrcph-thaloy) (2) and poly[imino(l-oxo-l,6-hexanediyl)J (3). 

On that basis, the poor photoconductivity of polyOS-N-carbazolylethylvinylelher)92, poly(acryloyl carbazole)91, poly( 1 -vinylnaphthalene) and polyacenaphthylene43 ... 

The relative importance of normal and excimer fluorescence has been studied as a function of temperature with poly-1-vinylnaphthalene [156],... 

Fig. 35. Temperature dependence of normal (/m) and excimer (/d) fluorescence intensities (in arbitrary units) for poly-1-vinylnaphthalene in 2-methyltetrahydrofuran (concentration 10"3 mole 1 I ) [reproduced with permission from Ref. 156].

With a glassy solution of poly-1-vinylnaphthalene, the delayed emission spectrum has been shown to consist of an emission having a mean lifetime of approximately 80 ms at the normal fluorescence wavelength, in addition to the phosphorescence having a mean lifetime of about 2 s [159]. The delayed fluorescence did not appear in the spectrum of 1-ethylnaphthalene. With the polymer it was found to be inhibited by piperylene, a well-known triplet quencher. These results have been explained by mutual annihilation of two excited triplet states produced by the absorption of two photons by the same polymer molecule. They are considered as strong evidence for migration of the excited triplet state in poly-1-vinylnaphthalene. In polyacenaphthalene, however, which is chemically very similar to poly-1-vinylnaphthalene (see p. 409), no delayed fluorescence could be detected in the same experimental conditions [155]. 

It has been shown [155,171] that the dependence of excimer emission intensity on acceptor concentration obeys the Stern—Volmer equation whether M or D is the donor, whereas a second-order equation is obtained if both types of excited state simultaneously act as donor. It seems that in poly-1-vinylnaphthalene and polyacenaphthalene films at room temperature, energy transfer to benzophenone occurs from M, although normal fluorescence cannot be detected in the emission spectrum of the polymers in these conditions [155]. Decay time measurements have shown that the excimers in solid polyvinylcarbazole are traps rather than intermediates in the energy transfer process [148]. With polystyrene, however, it has been clearly demonstrated that energy transfer to tetraphenylbutadiene occurs from both excimer and isolated excited chromophore [171]. 

In contrast, when 1% poly( 1-vinylnaphthalene) is blended with 99% polystyrene, the result is mainly polystyrene phosphorescence. These results lend themselves to the conclusion that energy migration must occur intramolecularly via the mani-... 

The presence of a freely diffusing quencher, however, underlies the essential difference between energy-transfer studies in the liquid and solid phases, although it is still possible to relate the Stem-Volmer relationship to quenching data in the solid. This has been demonstrated in the quenching of phosphorescence of poly(acenaphthylene) (23), poly(1-vinylnaphthalene) (24) and poly(styrene) (25) by piperylene in glasses at 77°K. 

The authors proposed a structural catalyst model based on the assumption of polymeric bonding of ruthenium metal clusters through the formation of ruthenium-aromatic ring bonds [259]. The validity of this contention was confirmed by synthesis of ruthenium complexes based on poly-1-vinylnaphthalene instead of polystyrene. It was demonstrated that both catalytic ruthenium-containing systems are active in the hydrogenation of unsaturated bonds in olefins, mononuclear aromatic hydrocarbons,... 

Commercial material can contain up to 2% of poly-1-vinylnaphthalene. Fractionally distil it under reduced pressure using a spinning-band column, dry it with CaH2 and again distil it under vacuum. Store it in sealed ampoules in a freezer. It has A-max (cyclohexane) at 210 and 320nm. The picrate has m 105-106°. [Beilstein 5 H 585,5 El 1773,5IV 1833.] It is an irritant. 

Abbreviations PIVN = poly(1-vinylnaphthalene) PVCz = poly(N-vinylcarbazole) PS = polystyrene PNMA = poly(naphthyImethacrylate) PINMMA = poly(l-naphthyl-methylmethacrylate) P(INMMA-A) = PINMMA terminated with anthracene P(NMA-VA)... 

Evidence for the failure of the assumptions inherent in the treatment discussed above to withstand empirical evaluation may be found both from steady state excitation and transient data. For example Nishijima [21] and David et al [22] have presented data (for poly 2- and 1-vinyl-naphthalenes, respectively) which indicate that does not increase in the manner expected in the high temperature region if excimer dissociation were dominant. More emphatically, Holden and Guillet [23] have tabulated individual rate parameters derived from transient decay data for poly(1-vinylnaphthalene) [23,24] and poly(1-naphthyImethacrylate)... 

More recently, using a revised kinetic scheme [17,26] (cf. section 4). Phillips et al. [25] have examined the temperature dependence of intramolecular excimer formation in poly(1-vinylnaphthalene) in THF under transient excitation conditions. It was shown that at no temperature within the region defined as "low temperature" in a Stevens-Ban presentation is the tenet valid. Furthermore, since the approach... 

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