A thermal expansion investigation of the melting point anomaly in trihalomesitylenes

Generally the order of melting point of halogenated compounds is found to be I > Br > Cl whereas, in the series of trihalomesitylenes the order follows as Br > I approximate to Cl. This melting point anomaly has been explained in terms of their thermal expansion behaviours. The order of thermal expansion in this series is found to be Br < I approximate to Cl.