Mesitylene

Triptycene films were formed by TVE and BC. TVE was carried out using an ULVAC EX200, and the film thickness was monitored using a quartz-crystal microbalance. BC was carried out using a custom-made deposition system in ambient air. The triptycene powder was dissolved in mesitylene (Wako chemicals) to obtain a 0.5 mM solution. The blade was made of glass. All substrates were heated to 50–60 °C with a silicone-rubber heater while depositing the triptycene/mesitylene solution. The blade speed was fixed to between 40 and 50 µm/s. In the present study, the TVE-Trip process required approximately 1 h, including the evacuation and cooling time, while the BC-Trip process required approximately 8.5 or 17 min for substrate areas of 2 × 3 cm² and 4 × 5 cm², respectively. After forming triptycene films by TVE and BC processes, all the substrates were annealed at 120 °C for 1 h under vacuum at around 100 Pa.

1,4-Dimethylbenzene and 1,3,5-tri(4-aminophenyl) benzene (TAPB) were purchased from TCI and used as received. Crystalline neat phosphoric acid was purchased from Sigma-Aldrich and used as received. Tetrahydrofuran (THF) was refluxed with sodium and benzophenone to remove water and oxygen before use. Dehydrated N, N-dimethylformide (DMF), acetonitrile (CH₃CN) and o-dichlorobenzene (o-DCB) were purchased from Kanto Chemicals. Dioxane, mesitylene, n-butanol and acetic acid were purchased from Wako Chemicals. 2,5-Dimethylterephthalaldehyde (DMeTP) was synthesised according to the reported method^{48 (link)}.