Poly benzenes, reaction with

In some cases POMs can oxygenate hydrocarbons. For example, the oxidation of alkanes and benzene by poly vanadate in CF3COOH to produce alkyl (phenyl) trifluoroacetates and ketones is stimulated by light [85]. In fact, the alkane and benzene reactions with the vanadate virtually do not proceed in the absence of light. On the other hand, ethylbenzene and toluene are rapidly oxidized in the dark reaction, even at 10 °C. 

Recently, Baneijee et al. prepared a series of difluoro monomers with pendent trifluoromethyl groups using a Pd(0)-catalyzed cross-coupling reaction (Scheme 6.32).242,243 These monomers were converted to poly(arylene ether)s by nucleophilic displacement of the halogen atoms on the benzene ring with several... 

The basic poly(phenylene vinylene) (PPV) polymer is commonly prepared by the sufonium prepolymer route developed by WessUng and Zimmerman in 1968 but much modified by subsequent workers. The synthesis starts from 1,4-bis(chloromethyl)benzene, via the bis-sulfonium salt formed by reaction with tetrahydrothiophene, and then polymerisation is effected to give the prepolymer by reaction with lithium hydroxide (Figure 3.39). Because of the inherent insolubility of PPV it is this prepolymer that is used to form the film coating on the substrate, for example by using a doctor blade technique. The prepolymer is converted into PPV on the substrate by heating in an oven under vacuum at 200 °C for 8-10 h. 

Benzene derivatives with two nucleofuges have been used in the preparation of polymeric materials with varying degrees of success. Poly(l,4-phenylene sulfide) has been prepared by condensation of p-di-chlorobenzene with sodium sulfide,99,100 and in a related process, diazonium ions have been shown to initiate the polymerization of p-halobenzenethiolate ions.101 In a preliminary study, poorly characterized polymers were obtained from reaction of equimolar amounts of p-dihalobenzenes and the enolate ions from ketones in the presence of excess base. When an excess of the ketone enolates was used, the normal p-disubstituted derivatives were formed.102... 

The reactions of poly(styryl)lithium in benzene with an excess of diphenyl-ethylene 272) and bis[4-(l-phenylethenyl)phenyl]ether158) also were found to proceed by a first order process. However, the reactions of poly(styryl)lithium with the double diphenylethylenes l,4-bis(l-phenylethenyl)benzene and 4,4 bis(l-phenyl-ethenyl)l,l biphenyl gave l58) non-linear first order plots with the gradients decreasing with time. This curvature was attributed to departure from a geometric mean relationship between the three dimerization equilibrium constants (Ka, Kb and Kab). The respective concentrations of the various unassociated, self-associated and cross-associated aggregates involved in the systems described by Equations (49) to (51) are dependent upon the relative concentrations of the two active centers and the respective rate constants which govern the association-dissociation events. 

Strong acid cation exchange resins manufactured by the sulphonation of polystyrene or poly divinyl benzenes undergo the following reaction with cations ... 

The nature of the solvent plays an important role in the reactions between carboxy-containing compounds and diazoalkanes. Protic solvents of the R-OH type can react with diazoalkanes in the presence of carboxylic acids to form the corresponding ethers Hence, in reactions with polymers dissolved in alcohols or alcohol-containing mixtures (poly(acrylic and methacrylic acids) etc.) the yield of the main reaction can decrease to 30—50% (with respect to ADM) 1 Consequently, when polymers soluble in aprotic solvents undergo anthryhnethylation, the reaction should be carried out in such solvents as benzene or toluene. 

Ma et al.177 synthesized a,co-dilithium poly(styrene-b-butadiene-b-styrene)s (PS-b-PBd-b-PS) by using l,3-bis(l-phenylethylenyl)benzene activated with 2 mol of s-BuLi as initiator for the sequential polymerization of butadiene and styrene in the presence of s-BuOLi in benzene. The cyclization reaction was performed under high dilution in cyclohexane with either dichlorodimethylsilane or MDPPE (Scheme 87). The cyclic copolymer was isolated by fractional precipitation. The only indication of the formation of this architecture was the lower intrinsic viscosity. 

TP here are very few examples in the literature of poly (arylene polysulfides). Perhaps the first such preparation was that of Fried el and Crafts (I), in which benzene reacted with sulfur in the presence of aluminum chloride. Within the last 15 years, several poly(arylene polysulfides) have been prepared by related reactions in which various aromatic compounds reacted with sulfur monochloride in the presence of Friedel-Crafts catalysts (2, 3, 4). A variation of this reaction has also been reported using a bifiunctional sulfenyl chloride (5) ... 

For example, poly(alkyl acrylates) with bromine end groups were reacted with allyl tri-n-butyltin and Cu(0) in benzene. After 3h, complete radical addition reaction was obtained, ll NMR confirmed the presence of the allyl function. 

PET reactions of benzylic silanes with polycyano-aromatic compounds have been applied to photoresist and electron-beam resist technologies. "" The photoreaction of poly(4-trimethylsilyl-methylstyrene) in benzene-acetonitrile with DCB affords insoluble polymer via photo-cross-linking, which contains 4-cyanophenyl-methyl groups. In the case of 1,2,4,5-tetracyanobenzene, soluble 2,4,5-tricyanophenylmethyl-substituted polystyrene is produced. But,... 

Functionalized XE-30S (a 3% cross-linked macroporous polystyrene with most probable pore size 130 nm), XAD-4 (a poly(divinylbenzene) with surface area >700 m /g and most probable pore size <5 nm), and PSP-12 (a macroporous poly(divinyl-benzene) with most probable pore size <5 nm) also have been studied by scanning electron micn robe (22)- Chloromethylation proceeded uniformly thro hout all three polymers. Reaction with lithium diphenylphosphide for 18 h in THF at room temperature, and photochemical metalation with phenanthrenechromium tricarbonyl, proceeded uniformly in XE-305, but primarily near the surfaces of XAD-4 and PSP-12. 

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