Isomerisation of 1,2,4-trichlorobenzene

Theoretical techniques have been applied to the problem of the isomerisation of 1,2,4-trichlorobenzene (124TCB). Semi-empirical methods have been used to study three proposed mechanisms for the isomerisation of 1,2,4-trichlorobenzene into 1,2,3 and 1,3,5-trichlorobenzene as well as examining the thermodynamic stabilities of protonated species and final products. Comparison with experimental observations has been possible. 

The isomerisation of 1,2,4-trichlorobenzene in this mechanistic scheme would begin by protonation, and would be followed by a 1,2 shift passing via a chloronium ion. 

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