Fig. 2: Molecular structures of the investigated compounds 1, 1F and 2 and DSC trace of compound 1.

a Molecular structures with molecular parameters. b DSC traces of the second heating and cooling runs (10 K min−1) of compound 1, measured between 60 and 140 °C to avoid crystallization; for the complete DSCs over a broader temperature range extending to lower temperatures, see Supplementary Fig. 1a.