Asahara and coworkers have reported that methyl methacrylate') and polymerize in the presence of an anionic surfactant without an initiator. They suggested that an interaction between the vinyl monomers and the micelle of the surfactant participates in the polymerization.We found that styrene polymerizes in an aqueous system on irradiation with a tungsten lamp in the presence of N-laurylpyridinium azide (1). A comparable polymerization is unknown and the reaction mechanism is still obscure. In this communication some observations will be described. Experiment a1 Part N-Laurylpyridinium azide (1):The preparation and analysis of 1 were performed according to the procedures reported previously4': 1 was prepared from N-laurylpyridinium chloride (LPC) and sodium azide by ion-exchange reaction (8 h) in purified tetrahydrofuran (THF) in the dark. The ion-exchange ratio was 98%. The chemical grade sodium azide was extracted with purified THF in a Soxhlet extractor before the ion-exchange reaction to remove THF soluble impurities, otherwise the obtained 1 became sometimes uneffective.Cetyltrimeth~~lammonium chloride (CTAC): Chemical grade product was recrystallized from THF. Cetyltrimethylammonium azide (CTAA): A similar ion-exchange procedure gave CTAA from CTAC;Vinyl monomers: All vinyl monomers were purified by usual methods.the ion-exchange ratio was 97 %. Photopolymerization

Benzidinetetrazonium chloride (BTC)–CuCl and BTC–FeCl2 complexes were thermally converted to benzene‐soluble poly‐4,4′‐biphenylene plus small amounts of insoluble material. The soluble fraction was more stable than the insoluble fraction when heated at 300–500°C, although the solubility decreased. BTC in water was converted to an insoluble material by addition of alkali or cuprous ammonia solution. The C/(H + Cl) ratio indicated the existence of three to five side groups for each twenty phenyl groups of the insoluble fraction, while that of the soluble fraction showed few such groups. The number increased to one or more side groups for each phenyl nucleus as both soluble and insoluble fractions were heated to 500°C. A thin film of soluble fraction deposited on a copper plate showed an electrical conductivity in the range 10−2–10−3 ohm−1 cm−1 at 25°C and an energy gap (ΔEg) of 0.2–0.3 eV. However, a compressed specimen of the same soluble fraction showed little conductivity. Solventsoluble samples of substituted poly‐4,4,‐biphenylene were prepared by the same procedure. These materials cracked on processing, and accurate conductivity measurements could not be made.

Hydrolyses of p-nitrophenyl acetate (PNPA) and 3-acetoxy-N,N,N-trimethylanilinium iodide (ANTI) catalyzed by poly[p-vinyl(thiopheno1)-co-acrylic acid] (PSH) were studied in the pH range of 8 -93. The reaction of PNPA followed pseudo-first-order kinetics and was found to be catalyzed by the thiophenolate ions on the polymer backbone. In the case of positively charged ANTI, the rate of catalysis showed substrate saturation phenomena and could be described by a Michaelis-Menten kinetics. This indicates that this reaction proceeds via a complex formed by electrostatic interaction between the substrate and the negatively charged polymer catalyst. When ionic strength was increased to 0,12 molA the reaction did not further follow the Michaelis-Menten kinetics, suggesting that the complexation constant or the reaction rate of the complex might vary with the amount of the substrate incorporated in the polymer domain. Positively charged N,N,N-trimethylanilinium iodide competively inhibited the PSHcatalyzed hydrolysis of ANTI.

Recently, the catalyses of ester solvolysis by synthetic polymers containing functional groups have received considerable attention, since these reactions may serve as models for enzymatic hydrolyses. On the other hand, metal ions play important r6les in many enzymic reactions. For example, zinc ion activates the carboxypeptidase A of bovine pancreas; the mechanisms were discussed in terms of the direct activation of the substrate and the change in the Michaelis-Menten constant 1,2).It is of interest to investigate the effects of metal ions in the synthetic polymer-catalyzed ester solvolyses, because those investigations may afford simplified kinetic models for the metal ion-containing enzymes. It was reported that the proton-catalyzed hydrolysis of an olefinic ester is accelerated characteristically by a sulphonic resin partially exchanged with silver ion3'. However, investigations on metal ion effects have not been reported for the ester solvolyses catalyzed by nucleophile groups located at synthetic polymers. The present communication is concerned with the effects of the silver ion in the solvolysis of an olefinic ester catalyzed by poly(acry1ic acid) (PAA).The silver ion binds to olefines by charge-transfer interaction4). Therefore, the olefinic ester is considered to form with this ion a positively charged complex, which is supposed to be concentrated around PAA by electrostatic interaction and, consequently, will be easily attacked by the carboxylate ions bound to the polymer chain. Thus, in the presence of silver ion the rate

It has been reported that metal ions promote the hydrolyses of a-amino esters'"). Breslow et al. have reported the reactions of coordinated substrates as models for a metalloenzyme, carboxypeptidaseThe authors previously reported that silver ion enhanced the poly(acry1ic acid) (PAA)-catalyzed hydrolysis of an olefinic ester, 2,4-dinitrophenyl vinylacetate"); a silver ion effect on the acetate ion-catalyzed hydrolysis of this ester, however, could not be found at that time, probably because of an experimental mistake. Later, this effect was observed by us and the reaction mechanism and kinetics were discussed''). This might be the first case in which an esterolysis was catalyzed by a metal ion via a weak interaction between the metal and the C=C double bond of the ester.In the present communication, we wish to report the new finding that the PAA-catalyzed hydrolyses of paraffinic esters such as 2,4-dinitrophenyl pentanoate were also accelerated by silver ion, whereas the acetate ion-catalyzed hydrolyses of those esters were slightly retarded by silver ion. Experimental PartMaterials 2,4-Dinitrophenyl acetate (I) was prepared from 2,4-dinitrophenol and acetic anhydride, mp. 72-73 "C (Lit.'": 72 "C). C&,N2O6 (2262)Other esters: An equimolar (0,03 mol) solution of carboxylic acid, 2,4-dinitrophenol, and dicyclohexylcarbodiimide in ethyl acetate (40 ml) was allowed to stand a4 room temp. for 1 day. After the formed dicyclohexylurea had been separated out by filtration, the solvent was evaporated. The crude product obtained was chromatographically purified by passing through a silicagel column with benzene.