Polymers with Condensed Aromatic Rings

A. Conjugated Polymers with Condensed Aromatic Rings. 274... 

These monomers polymerize with W, Mo, and Rh catalysts, where the polymer yield usually decreases in the order of W>Mo>Rh. The cis content of the polymers inaeases in the order of Wpolymer solubility decreases in this order. Both 1- and 2-naphthylacetylenes polymerize in high yields with W catalysts. 9-Anthrylacetylene polymerizes with W catalysts into a polymer insoluble in any solvent. However, if a long n-hexoxycarbonyl group is introduced at the 10 position, the polymer formed becomes soluble. This polymer has dark purple color. 1- and 2-Anthrylacelylens are sterically less hindered and the polymers formed are solvent soluble. These polymers having condensed aromatic rings are generally deeply colored (dark brown to dark purple) and show third-order nonlinear optical properties. 

The pore walls of cross-linked PSDVB adsorbents include the aromatic rings as the main structural unit. Orientation of these rings in tangles of polymer chains is rather random in contrast to carbon adsorbents with the pore walls with the ordered condensed aromatic ring systems. Therefore, it is of interest to compare the confined space effects on the interfacial behavior of liquids co-adsorbed onto adsorbents of these two types (Gun ko et al. 2008e). 

Polymers with pendant or in-chain electronically isolated photoactive groups with large 7i-electron systems, for example, aromatic amino groups, like carba-zole or condensed aromatic rings, like anthracene... 

Aromatic polyimides are the first example we shall consider of polymers with a rather high degree of backbone ring character. This polymer is exemplified by the condensation product of pyromellitic dianhydride [Vll] and p-amino-aniline [Vlll] ... 

The main chain of these polymers contains, as the principal component, five- or six-membered heteroaromatic rings, ie, imides, which are usually present as condensed aromatic systems, such as with benzene (phthalimides, 3) and naphthalene (naphthalimides, 4) rings. 

The second step is the condensation reaction between the methylolphe-nols with the elimination of water and the formation of the polymer. Crosslinking occurs hy a reaction between the methylol groups and results in the formation of ether bridges. It occurs also by the reaction of the methylol groups and the aromatic ring, which forms methylene bridges. The formed polymer is a three-dimensional network thermoset ... 

It would be preferable to incorporate both fluorescent and electron transport properties in the same material so as to dispense entirely with the need for electron-transport layers in LEDs. Raising the affinity of the polymer facilitates the use of metal electrodes other than calcium, thus avoiding the need to encapsulate the cathode. It has been shown computationally [76] that the presence of a cyano substituent on the aromatic ring or on the vinylene portion of PPV lowers both the HOMO and LUMO of the material. The barrier for electron injection in the material is lowered considerably as a result. However, the Wessling route is incompatible with strongly electron-withdrawing substituents, and an alternative synthetic route to this class of materials must be employed. The Knoevenagel condensation... 

There have been a number of different synthetic approaches to substituted PTV derivatives proposed in the last decade. Almost all focus on the aromatic ring as the site for substitution. Some effort has been made to apply the traditional base-catalyzed dehydrohalogenation route to PTV and its substituted analogs. The methodology, however, is not as successful for PTV as it is for PPV and its derivatives because of the great tendency for the poly(u-chloro thiophene) precursor spontaneously to eliminate at room temperature. Swager and co-workers attempted this route to synthesize a PTV derivative substituted with a crown ether with potential applications as a sensory material (Scheme 1-26) [123]. The synthesis employs a Fager condensation [124] in its initial step to yield diol 78. Treatment with a ditosylate yields a crown ether-functionalized thiophene diester 79. This may be elaborated to dichloride 81, but pure material could not be isolated and the dichloride monomer had to be polymerized in situ. The polymer isolated... 

It is important to clarify whether catalyst-transfer condensation polymerization is specific to polythiophene, or whether it is generally applicable to the synthesis of well-defined it-conjugated polymers. We investigated the synthesis of poly(p-phenylene), to see whether a monomer 28 containing no heteroatom in the aromatic ring would undergo catalyst-transfer polymerization. However, all polymers obtained in the polymerization with Ni(dppp)Cl2, Ni(dppe)Cl2, or Ni(dppf)Cl2 possessed low molecular weights and broad polydispersities. Nevertheless, we found that LiCl was necessary for opti-... 

In order to get more structurally pure polyPc a new way may start from multifunctional low molecular Pc. Co(II), Ni(II) and Cu(II) containing bis(dicarboxybenzoyl) Pc diimides were converted with various aromatic diamines in N-methylpyrrolidone to soluble polyamides which react to insoluble polyimides (9S) by heating to 473 K ). Melt and solution condensation of (12 b) and 3,3 -diaminobenzidine led to unsoluble polymers (99) with Pc-rings linked by benzimidazole units ). 

This type of polymer is used, for example, to make resins with strong anion exchange properties[5]. Because the amino groups directly connected to the aromatic ring are weak bases, further methylation can be applied to form quaternary amines that are stronger bases. Pyrolysis of this type of polymer gives indication of both type of condensation. 

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