Triphenyl phosphite

Thiourea (99.0%, purity) and triphenyl phosphite (98.0%, purity) were obtained from Macklin (Beijing, China). Terephthalaldehyde (98.0%, purity), pyridinium trifluoromethanesulfonate (98.0%, purity) (as protic ionic liquid), and silver nitrate (99.8%, purity) (AgNO₃) were purchased from Aladdin (Beijing, China). Solvents, such as acetonitrile (CH₃CN), ethanol, and methanol were obtained from a commercial supplier (Sigma Aldrich, Cairo, Egypt) and used without further drying and purification. Deionized water was used to prepare all solutions and suspensions.

N,N-dimethylformamide (DMF, 99.8%), Terephthalic acid (TPA, 99%), and Ferric nitrate nonahydrate (Fe(NO₃)₃·9H₂O, 95%) were all purchased from J&K Scientific Ltd. (Beijing, China). ethanol (EtOH, 95%) was purchased from Beijing Tongguang Co., and 3-hydroxyphenyl-phosphinyl propanoic acid (CEPPA) was provided by Zhenbei Co., Ltd. (Hangzhou, China). Pure Terephthalic acid (PTA, industrial grade) and Ethylene glycol (EG, industrial grade) were supplied by the Sinopec Group (Tianjin, China). Triphenyl phosphite (TPI, analytical pure) and Diantimony trioxide (Sb₂O₃, analytical pure) were purchased from Macklin Biochemical Co., Ltd. (Shanghai, China). HyMax 1010 (1010, industrial grade) was provided by Langyi Functional Materials Co., Ltd. (Shanghai, China). All chemicals were used directly without further purification.