29 Pd(PPh3)4 (347 mg, 0.3 mmol), tetra(ethylene glycol) (570 mg, 3 mmol), Ti(OC4H9)4 (1 ml, 3 mmol), and 1-butanol (3 mL, 32.7 mmol) were added a 50 mL of Teflon-lined autoclave and stirred at 120 °C for 8 h to give a black suspension. Secondly, 2-aminoterephthalic acid (H2ATA) (2.178 g, 12 mmol) was dissolved in 18 ml of N, N-dimethylformamide (DMF), and 2 mL of MeOH to give a brown solution. Then it was mixed with Pd precursor and then heated at 150 C for 48 h before it was naturally cooled down to room temperature. The green precipitate was washed with MeOH and dried in a vacuum at 80 C for 12 h.