The RO3-DADQs show an overall trend of decreasing melting point with increasing chain length (Figures , Table ); this is a typical sign of the inf luence of the increasing conf ormational f lexibility and the consequent poorer packing with increase in the number of methylene groups in the chain. The exception observed with i-3O3 can be attributed to the dif f erent chain topology. The dif f erent trend in the case of RO2-DADQs (Figure ) possibly arises due to the competition between the intra and intermolecular H-bond interactions discussed below. More interestingly, the RO3-DADQs exhibit crystallization transitions on cooling (Figure , Table ). Characteristic decrease in the thermal hysteresis f or the phase change is also observed in the RO3-DADQs (Figure ), arising due to the dif f erence in the heat storage and release processes, and the ef f ects of subcooling/superheating depending on the heating and cooling rates. DSC also provides usef ul inf ormation about potential PCMs through direct insight into the f ormation and stabilization of the A and C states. The stability of ROR′-DADQs upon melting enabled us to study the thermal cycling of these materials to unravel the melt-quench-recrystallization behavior; we discuss the PCM behavior of selected systems later.