With water

With water. Rozenberg et al. (31) have shown that in the BF3/ ECH catalyzed polymerization of THF water can act as a chain transfer agent. They found that lower molecular weight polymers were produced when the amount of water added was less than the catalyst concentration. At the same time the polymerization rate remained the same. The mechanism they proposed for the reaction is as follows  

When these reactions are written as in equation 34, the process becomes analogous to the reaction with dialkyl ether (equations 27 and 28). 

Sims (40) has studied the effects of water on PF5 initiation of THF polymerization (Section IIIB2b). Possibly, in addition to cocatalysis and destruction of catalyst, his results are complicated by transfer. 

With polymer oxygen. The oxygen atoms in the polymer chain itself are really a kind of dialkyl ether and especially in the later stages of the polymerization can react in the same way (equation 27) to form an oxonium ion  

Rozenberg et al. (51) used the reaction shown in equation 35 to explain the large increase in the viscosity of the reaction mixture that they observed after most of the monomer had polymerized. As evidence they offered the observation that the addition of an amount of metha-nolic KOH comparable to the number of active centers caused a marked reduction of viscosity. They associated this with a breakdown of the product of equation 35. Sims (37) has made similar observations. He suggests that the breakdown may be associated with a hydrolysis of the phosphate linkages in the chain of the final product shown in equation 8. Equation 6 a suggests that the explanation for Rozenberg s observations may be similar to Sims, i. e. a hydrolysis of borate esters occurs. 

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Adams catalyst, platinum oxide, Pt02 H20. Produced by fusion of H2PtCl6 with sodium nitrate at 500-550 C and leaching of the cooled melt with water. Stable in air, activated by hydrogen. Used as a hydrogenation catalyst for converting alkenes to alkanes at low pressure and temperature. Often used on Si02... 

It is prepared by fully chlorinating toluene. When heated with water at 100°C, or with lime, benzoic acid is obtained, benzoyl The group PhC(O)-. 

Boron III) oxide, B2O3, is obtained by ignition of boric acid. Combines with water to reform B(0H)3. The fused oxide dissolves metal oxides to give borates. 

Carbon suboxide, C3O2, OCCCO. M.p. — 107 C, b.p. 6-8°C. A toxic gas (malonic acid plus P2O5) which polymerizes at room temperature. Reforms malonic acid with water. 

CCls CHO. A colourless oily liquid with a pungent odour b.p. 98°C. Manut actured by the action of chlorine on ethanol it is also made by the chlorination of ethanal. When allowed to stand, it changes slowly to a white solid. Addition compounds are formed with water see chloral hydrate), ammonia, sodium hydrogen sulphite, alcohols, and some amines and amides. Oxidized by nitric acid to tri-chloroethanoic acid. Decomposed by alkalis to chloroform and a methanoate a convenient method of obtaining pure CHCI3. It is used for the manufacture of DDT. It is also used as a hypnotic. 

Diehlorine heptoxide, CI2O,. M.p. —91-5 C, b.p. 82"C, the most stable chlorine oxide but still explosive (HCIO4 plus P2OS), gives HCIO4 with water. 

Chromium trioxide. CrOj. Red precipitate from [Cr04p plus cone. H2SO4, m.p. 198 C, loses oxygen at 420" C. CrOa is a powerful oxidizing agent and is used as such. Acidic, gives [Cr04] - with water. 

The diazonium salts usually decompose when warmed with water to give a phenol and nitrogen. When treated with CuCl, CuBr, KI, the diazo group is replaced by chlorine, bromine or iodine respectively (Sandmeyer reaction). A diazonium sulphate and hydroxyl-amine give an azoimide. The diazonium salt of anthranilic acid (2-aminobenzoic acid) decomposes to give benzyne. ... 

C2H3N. Colourless liquid with strong ammoniacal smell b.p. 56 C. Miscible with water and strongly basic. Prepared commercially from 2-aminoelhanol. Pure dry aziridine is comparatively stable but it polymerizes explosively in the presence of traces of water. Carbon dioxide is sufficiently acidic to promote polymerization. 

HCOOCHjCHj. Colourless liquid with the odour of peach-kernels b.p. 54 C, Prepared by boiling ethanol and methanoic acid in the presence of a little sulphuric acid the product is diluted with water and the insoluble ester separated and distilled. Used as a fumigant and larvicide for dried fruits, tobacco and foodstuffs. It is also used in the synthesis of aldehydes. 

Hoesch synthesis A variation of the Gattermann synthesis of hydroxy-aldehydes, this reaction has been widely applied to the synthesis of anthocyanidins. It consists of the condensation of polyhydric phenols with nitriles by the action of hydrochloric acid (with or without ZnCl2 as a catalyst). This gives an iminehydrochloride which on hydrolysis with water gives the hydroxy-ketone. 

White crystals m.p. 162-164 C. ll can be prepared by the fermentation of sugar with the mould Aspergillus lerreus or by healing citra-conic anhydride with water at ISO C. Electrolysis of the potassium salt in solution gives allene. Itaconic acid is used as a comonomer in plastics its esters are polymerized to lubricating oils and plasticizers. 

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