Triphenylmethyl chloride, color solvents

An activation energy of this magnitude would lead to an unobservably slow reaction at normal temperature. There is an abundance of evidence that carbocations can be intermediates in nucleophilic substitution reactions. Carbocation formation in solution is feasible because of the solvation of the ions that are produced. One of the earliest pieces of evidence for the existence of carbocation intermediates was the observation that triphenylmethyl chloride (trityl chloride) gave conducting solutions when dissolved in liquid sulfur dioxide, a polar non-nucleophilic solvent. Trityl chloride also reacted with Lewis acids, such as aluminum chloride, to give colored salt-like solids. 

Advantage can be taken of the ionizing and dissociating effects produced by a solvent to activate inert molecules and initiate a polymerization. For instance, triphenylmethyl chloride in pure sulfuric acid solution undergoes an instantaneous ionization and produces a triphenylmethylium cation with a characteristic red color ... 

In an attempt to demonstrate the existence of pentavalent nitrogen, Schlenk and Holtz studied the reaction of triphenylmethyl sodium with tetramethylammonium chloride (52). The highly colored material was strongly conducting in polar solvents and could be identified as a salt, the stability of which is due to the resonance stabilization of the triphenyl-methide anion. In the absence of such stabilizing substituent effects (53), as with n-butyl or another alkyllithium reagent, a metalation of the tetramethylammonium cation occurs, which leads to type I products (18) ... 

---