Methyl ParabenA New Polymorph?

The crystal structure of methyl paraben was elucidated at 113K (1), while the structure at room temperature (2) has been determined previously (Lin, X. T. Chin. J. Struct. Chem. 1983, 2 (3), 213). There is a slight lengthening of the b axis in the low-temperature structure and twisting of the ester group resulting in small but statistically significant differences in the PXRD patterns between 1 and 2. The phase transformation occurs gradually over the full temperature range (293−113 K).