All compounds were crystallized in plate-like shape with varying crystal sizes. It allowed us to define the longest direction as length and the thinnest direction as thickness. The widest face appears perpendicular to the thickness. X-ray crystallographic analysis determined crystal structures (Supplementary Table ). Eight out of ten crystals had common features; relatively strong molecular layers were stacked in a specific direction via interlayer van der Waals forces (Figure ). This is because the interlayer interactions are formed between tert-butyl groups between two molecular layers. There are two types of stacking directions: crystals with molecular layers stacked in the thickness direction and crystals stacked at an angle nearly perpendicular to the thickness. Among these, crystals with naphthyl groups all have molecular layers stacked in the thickness direction (Figure ). For molecules with halogens, all crystals except those with -F group formed similar molecular arrangements (Figure ). Two crystals of compounds 2 and 7 did not show molecular layer stacking. The crystal of compound 2 forms hydrogen-bonded dimers due to -COOH group but has a different molecular packing with crystal of compound 1, which also forms hydrogen-bonded dimers. The crystal of compound 7 has a significantly different molecular packing compared to other halogenated crystals and does not show molecular layer stacking.