## 2 Materials and Methods
### Mechanochromism Study  
The as-synthesized compounds were ground with a pestle and mortar for 5 min. The fumed samples were prepared by forming the ground powders with acetone for 60 s. The fumed samples were heated at a temperature of 120 \({}^{\circ}\)C for 10 min. Synthesis of **TPE-Se**: This was molecule prepared following our reported paper [34]. Sebacic acid (0.1 g, 0.5 mmol) and amino-TPE (0.407 g, 1.08 mmol) were added to DMF (8 mL) at 0 \({}^{\circ}\)C and stirred for 10 min under nitrogen atmosphere, followed by addition of EDCI (0.230 g, 1.48 mmol), DMAP (0.181 g, 1.48 mmol) and TEA (0.2 mL, 1.40 mmol) at once. The reaction mixture was stirred overnight at room temperature. Reaction completion was checked by TLC analysis. The reaction mixture was then diluted in chloroform followed by washing with 1 M HCl then NaHCO\({}_{3}\) 10%, and water to remove excess DMF. The crude produced after evaporation was washed with methanol and 2-4 drops of HCl and was filtered to remove excess amine, resulting in the white-coloured solid of **TPE-I** (0.4 g, 43%). \({}^{1}\)H-NMR (300 MHz, CDCl\({}_{3}\)) \(\delta\) ppm: 7.13-6.96 (m, 38H), 2.33-2.28 (m, 4H), 1.70-1.58 (m, 4H), 1.34-1.27 (m, 8H); \({}^{13}\)C-NMR (75 MHz, CDCl\({}_{3}\)) \(\delta\) ppm: 171.1, 143.7, 143.6, 132.0, 131.4, 131.3, 126.4, 126.3, 118.7, 37.7, 29.0, 28.9, 25.4; Mass (ESI) \(m/z\): calculated for C\({}_{62}\)H\({}_{56}\)N\({}_{2}\)O\({}_{2}\) 860.43, found: 860.41 (M)\({}^{+}\); Elemental analysis for C\({}_{62}\)H\({}_{56}\)N\({}_{2}\)O\({}_{2}\): calculated = C, 86.48; H, 6.56; N, 3.25; found = C, 86.53; H, 6.62; N, 3.28. Synthesis of **TPE-Az**: Azelaic acid (0.1 g, 0.5 mmol) and amino-TPE (0.406 g, 1.08 mmol) were added to DMF (8 mL) at 0 \({}^{\circ}\)C and stirred for 10 min under an argon atmosphere, followed by addition of EDCI (0.230 g, 1.48 mmol), DMAP (0.181 g, 1.48 mmol) and TEA (0.2 mL, 1.40 mmol) all at once. The reaction mixture was stirred overnight at room temperature. Reaction completion was checked by TLC analysis. The reaction mixture was then diluted in chloroform followed by washing with 1 M HCl, then NaHCO\({}_{3}\) 10%, and then water to remove excess DMF. The crude produced after evaporation was washed with methanol and 2-4 drops of HCl and, after filtration to remove excess amine, the white-coloured solid **TPE-Az** was obtained (53%). \({}^{1}\)H-NMR (300 MHz, CDCl\({}_{3}\)) \(\delta\) ppm: 7.13-6.96 (m, 38H), 2.33-2.28 (m, 4H), 1.70-1.58 (m, 4H), 1.34-1.27 (m, 6H); \({}^{13}\)C-NMR (75 MHz, CDCl\({}_{3}\)) \(\delta\) ppm: 171.19, 142.76. 141.64, 137.38, 135.32, 128.43, 127.37, 121.75, 37.74, 29.01, 28.90, 25.40. Mass (ESI) \(m/z\): calculated for C\({}_{61}\)H\({}_{54}\)N\({}_{2}\)O\({}_{2}\) 846.41, found 846.40 (M)\({}^{+}\); Elemental analysis for C\({}_{61}\)H\({}_{54}\)N\({}_{2}\)O\({}_{2}\): calculated = C, 86.49; H, 6.43; N, 3.31; found = C, 86.53; H, 6.62; N, 3.35. Synthesis of **TPE-Su**: Suberic acid (0.1 g, 0.5 mmol) and amino-TPE (0.460 g, 1.22 mmol) were added to DMF (8 mL) at 0 \({}^{\circ}\)C and stirred for 10 min under an argon atmosphere, followed by addition of EDCI (0.230 g, 1.48 mmol), DMAP (0.181 g, 1.48 mmol) and TEA (0.2 mL, 1.40 mmol) all at once. The reaction mixture was stirred overnight at room temperature. Reaction completion was checked by TLC analysis. The reaction mixture was then diluted in chloroform followed by washing with 1 M HCl then NaHCO3 10%, and finally water to remove excess DMF. The crude product after evaporation was washed with methanol and 2-4 drops of HCl, and was filtered to remove excess amine, obtaining a white-coloured solid of **TPE-Su** (52%). \({}^{1}\)H-NMR (300 MHz, CDCl3) \(\delta\) ppm: 7.26-6.93 (m, 38H), 2.35-2.30 (m, 4H), 1.73-1.66 (m, 4H), 1.34-1.27 (m, 4H); \({}^{13}\)C-NMR (75 MHz, CDCl3) \(\delta\) ppm: 174.5, 141.0, 140.0, 137.7, 135.1, 128.7, 128.3, 128.1, 127.9, 121.5, 38.3, 27.9, 25.5.