Poly /imidazole

Recently, Yamada et al. (2012) reported that the self-assembly of CUSO4 and a poly(imidazole-acrylamide) amphiphile afforded a highly efficient and recyclable solid-phase catalyst for click reactions. Even 4.5-45 mol ppm of the amphiphilic... 

Synthetic approaches to produce polymers with desirable biomedical characteristics for this class of materials have been extensively reviewed (Allcock, 1990 Crommen et al, 1993). Poly[(amino acid ester) phos-phazenes] are knovm to be susceptible toward hydrolytic degradation and hold promise as degradable materials. Recently, Laurencin etal (1987) used a poly(imidazole methylphenoxy) phosphazene to study the release characteristics ofBSA. Protein release was demonstrated using C-labeled BSA in a 20% imidazole-substituted polyphosphazene. Release from this matrix consisted of an initial burst of almost 25% of the protein, followed by release over several hundred hours in which a total of 55% of the protein was released. Polymer degradation for the 20% imidazole-substituted polyphosphazene was also studied and found to be quite slow, with 4% of the polymer degraded in 600 hr. 

Poly(imidazole)amides, a new class of heteroaromatic polyamides, were prepared from the polymerization of amino acids and acid chlorides to yield low to moderate molecular weight polymers. These materials are thermally stable in excess of 300°C, under nitrogen atmosphere Presently, we are investigating methods to increase molecular weights of these polymers as well as preparing new AB monomers, as shown below. 

Much work has been done on this interesting group of condensation polyimides [219]. Trying to combine the good thermal stability of other heterorings and the availability of polyimide monomers, a considerable number of mixed polyheterocycles has been synthesized. Among other heterocyelic copolyimides, poly(imidazole imide)s [220,221], poly(oxadiazole imide)s [222,223], poly(benzazole imide)s [224,225], poly(quinoxaline-imide)s [226], and poly(quinazolinedione imide)s [227] have been synthesized. 

Mangiatordi GF, Butera V, Russo N et al (2012) Charge transport in poly-imidazole membranes a liesh appraisal of the Grotthuss mechanism. Phys Chem Chem Phys 14 10910-10918... 

Recently, the quaternized poly-4-vinylpyridine, 50-54 (QPVP) was found to be an electron acceptor in the charge-transfer interactions 104 Ishiwatari et al.105) studied alkaline hydrolyses of p-nitrophenyl-3-indoleacetate 58 (p-NPIA) and N-(indole-3-acryloyl) imidazole 59 (IAI) (electron donor) in the presence of QPVP. The fcobs vs. polyelectrolyte concentration plots are shown in Fig. 12. As is seen in... 

Shimidzu etal.111 studied the catalytic activity of poly (4(5)-vinylimidazole-co-acrylic add) 60 (PVIm AA) in hydrolyses of 3-acetoxy-N-trimethylanilinium iodide 61 (ANTI) and p-nitrophenylacetate 44 (PNPA). The hydrolyses of ANTI followed the Michaelis-Menten-type kinetics, and that of PNPA followed the second-order kinetics. Substrate-binding with the copolymer was strongest at an imidazole content of 30 mol%. The authors concluded that the carboxylic acid moiety not... 

Cationic polyelectrolytes containing imidazole groups have been investigated by some researchers. Morawetz et alU4 first found that a cationic polymer, poly (l-vinyl-3-ethylimidazolium iodide), 65 (PQMelm), enhanced the hydrolyses of the negatively charged esters, i. e. NABA and 4-acetoxy-3-nitrobenzenesulfonate 66 (NABS). At intermediate pH, a large catalytic effect was observed and this was... 

We recently synthesized cationic polymers containing imidazole (e g. 68 (SZ811) and 69 (SZ11—3—3)] by reacting poly [N-(2,4-dinitrophenyl)-4-vinyl-pyridinium chloride] with histamine or histamine mixed with other amino derivatives ll8 The hydrolyses of neutral and anionic esters with the models followed saturation kinetics in alkaline media. 

Poly (ethylene oxide) macromonomers72 761 are made in a similar way, as the alkoxide end group is reactive enough towards benzylic halides. With methacryloyl chloride, side reactions are involved. It is better to first protonate the PEO, and then to have it react with methacryloyl chloride in the presence of some triethyl amine. One can also react co-hydroxy polyethylene oxide) with methacryloyl imidazole, or with methacrylic acid in the presence of dicyclohexyl carbodiimide (DCCf)77). 

As a further approach for novel electrolytes appropriate for selective cation transport, we have prepared poly(organoboron halide)-imidazole complexes.35 Even though boron-amine complexes are widely known materials reported by the early works of H. C. Brown et al.,52-54 they had not been investigated as solvents or electrolytes to the best of our knowledge. 

Figure 5 Temperature dependence of ionic conductivity for poly(organoboron halide)-imidazole complexes in the presence of various lithium salts.

Figure 6 VFT plots for poly(organoboron halide)-imidazole complexes. 

Table 2 VFT Parameters for Poly(organoboron halide)-imidazole Complexes...

Figure 13.13 Poly(aryl ether) dendrimers with a porphyrin core and dendritic imidazoles...

Imidazole units have been substituted on poly(vinyl alcohol) chains to the extent of 19-51% as shown in Equation 14 (54). This reaction was run 1-5 days as a 1% solution in DMF at 85°C. Using the sequence of reactions outlined in Equation 15, 6-methylthio-purine units have been placed on the poly(vinyl alcohol) backbone (55). These polymers might be useful in treating cancer or leukemia since the parent compound, 6-mercaptopurine, is used in this way. 

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. 

First-Order Observed Rate Constants for 1 1.95 Imidazole-Phenol Copolymer, Poly-4(5)-vinylimidazole, and Imidazole-Catalyzed Solvolyses of PNPA° ... 

Copolymer of 4(5)-vinylimidazole and p-vinylphenol Poly-4(5)-vinylimidazole Imidazole... 

As one might expect the rate of p-nitrophenyl heptanoate hydrolysis increased at low ethanol concentrations as a result of apolar binding. The rate of p-nitrophenyl acetate hydrolysis also increased markedly at low ethanol concentration. This finding was explained by a conformational effect on the polymer, that is, lower ethanol concentration brings about a shrinkage of the polymer, which increases concerted interactions of the imidazole residues. The hydrolysis of 3-nitro-4-dodecanoyloxybenzoate was found to be 1700 times faster in the presence of poly[4(5)-vinylimidazole] compared to free imidazole (77). A double-displacement mechanism was demonstrated for this system (75). 

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