The suggested role of partial dislocations in the single crystal ? single crystal phase transition of a cyclo-octane molecular cationic salt

It is suggested that the facile low-temperature solid-state inter-conversion of the α- and β-phases of 5-methyl-1-thia-5-azoniacyclo-octane 1-oxide perchlorate occurs on recurrent (102) type planes. The mechanism, which is likely to be of general validity in organic solid-state chemistry, dispenses with the need to postulate co-operative conformational changes on half of the molecular cations (mol-ions) in each row and in each column, and also explains all the known experimental facts relating to the transition.