Potassium triphenylmethyl derivatives

Another differential reaction is copolymerization. An equi-molar mixture of styrene and methyl methacrylate gives copolymers of different composition depending on the initiator. The radical chains started by benzoyl peroxide are 51 % polystyrene, the cationic chains from stannic chloride or boron trifluoride etherate are 100% polystyrene, and the anionic chains from sodium or potassium are more than 99 % polymethyl methacrylate.444 The radicals attack either monomer indiscriminately, the carbanions prefer methyl methacrylate and the carbonium ions prefer styrene. As can be seen from the data of Table XIV, the reactivity of a radical varies considerably with its structure, and it is worth considering whether this variability would be enough to make a radical derived from sodium or potassium give 99 % polymethyl methacrylate.446 If so, the alkali metal intitiated polymerization would not need to be a carbanionic chain reaction. However, the polymer initiated by triphenylmethyl sodium is also about 99% polymethyl methacrylate, whereas tert-butyl peroxide and >-chlorobenzoyl peroxide give 49 to 51 % styrene in the initial polymer.445... 

A 1-Pyrroline V-oxides dimerize readily in alkaline media.335 Different products are obtained on treatment of 2,2-dimethyl-d1-pyrroline V-oxide with sodamide or triphenylmethyl sodium.338 Sodium-potassium alloy in ethylene glycol produces a derivative of 1, r-dihydroxy-2,2 -dipyrrolidyl.337... 

Schlenk and Marcus in 1914 found that triphenylmethyl chloride reacted with sodium amalgam in dry ether solution, when the operation was carried out in an atmosphere of nitrogen. The resulting compound, sodium triphenylmethyl, was a brick-red mass, decomposed by moisture or carbon dioxide. Kraus and Kawamura in 1928 showed that triphenylmethyl chloride reacts with sodium and potassium in liquid ammonia, but that the potassium compound is more stable than the sodium derivative. A number of compounds similar in structure to triphenylmethyl have since been sho wn to give similar reactions. Rubidium and esesium also form similar derivatives. ... 

Rubidium triphenylmethyl, RbCPhg, prepared in a similar manner to the lithium compound, is a dark-red powder resembling the sodium and potassium derivatives. It gives a blood-red solution in ether. 

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