Poly nonconjugated polymer

BS Harrison, TJ Foley, AS Rnefely, JK Mwaura, GB Cunningham, TS Kang, M. Boug Lettaya, JM Boncella, JR Reynolds, and KS Schanze, Near-infrared photo- and electroluminescence of alkoxy-substituted poly(p-phenylene) and nonconjugated polymer /lanthanide tetraphenylporphirin blends, Chem. Mater., 16 2938-2947, 2004. 

The series of polymers includes the parent poly(benzobis(imidazole)) (PBBI), poly (benzobis(imidazole)vinylene) (PBIV), poly(benzobis(imidazole)divinylene) (PBIDV), poly(benzobis(imidazole)-l,4-phenylenebis(vinylene)) (PBIPV) and poly(benzimidazole-divinylene) (PBBIDV). The new nonconjugated polymer poly(benzobis(imidazole)(dode-camethylene) (PBIC12) as well as the previously reported poly(p-phenylenebenzobis (imidazole)) (PBZI) were also synthesized for the purposes of comparative studies. The XH NMR spectrum of PBIDV in deuteriated nitromethane containing aluminum trichloride, shown in Figure 7, exemplifies the results. 

It is also possible to adjust both the color and the quantum yield by doping the material with highly fluorescent recombination centers, as often done in inorganic LEDs. This has not yet been much explored in CPs. However, a new type of polymer LED has been demonstrated in which the active element is a dye in the form of small clusters or isolated molecules dispersed in a nonconjugated polymer such as poly (methylmethacrylate) [296] or polystyrene. Performances are comparable to those of present CP LEDs this may yield a new generation of polymer LEDs. 

The analysis of current-voltage characteristics provides new insight into conductivity control in thin poly(diphenylenephthalide) films by changing voltage on the middle electrode. Thus, possibility of nonconjugate polymer application in thin-film vertical transistor has been shown. 

In some cases, nonconjugated polymers with a lumophore as a side chain, such as polyvinylcarbazole (PVK) and poly(2-vinylnaphthalene), also show wavelengths in the deep blue region that originated from the excimer level, as seen in Table 5 [145,146]. 

Figure 3.4 Absorption spectra of synthetic nonconjugated polymers. PPVK poly(phenyl vinyl ketone) PMVK poly(methylvinylketone) PSt polystyrene PMMA poly(methyl methacrylate) PVAc poly(vinyl acetate). Adapted with permission from Ref [4] 2007, Wiley-VCH.

Figure 13 shows the irreversible conversion of a nonconjugated poly (p-phenylene pentadienylene) to a lithiun-doped conjugated derivative which has a semiconducting level of conductivity (0.1 to 1.0 S/cm) (29). Obviously, the neutral conjugated derivative of poly (p-phenylene pentadienylene) can then be reversibly generated from the n-type doped material by electrochemical undoping or by p-type compensation. A very similar synthetic method for the conversion of poly(acetylene-co-1,3-butadiene) to polyacetylene has been reported (30), Figure 14. This synthesis of polyacetylene from a nonconjugated precursor polymer containing isolated CH2 units in an otherwise conjugated chain is to be contrasted with the early approach of Marvel et al (6) in which an all-sp3 carbon chain was employed.

The formation ofC—C bonds between aromatic rings is an important step in many organic syntheses and can be accomplished by chemical, photochemical, or electrochemical means. As was noted earlier, fundamental considerations of the parameters for a dielectric which must be dealt with in designing a thermally stable, low-dielectric-constant polymer naturally lead one to consider rigid-rod, nonconjugated aromatic polymers containing no lossy functional groups. A structure such as poly(naphthalene) is a likely candidate. 

Nonconjugated poly[l,3-propanedioxy-l,4-phenylene-l,2-ethenylene(2,5-bis(tri-methylsilyl)-l,4-phenylene)- l,2-ethenylene-l,4-phenylene] (DSiPV) and conjugated MEH-PPV polymers are mixed by changing their weight ratios in 1,2-dichloroethane. The films of the blend polymers could be spin-cast from 1,2-dichloroethane solution with excellent reproducibility. AFM (atomic force microscopy) and SEM images show no indication of phase separation or layer formation due to the immiscibility of two polymers. The structures of DSiPV and MEH-PPV are shown in Fig. 24. 

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