Patent ID: 8735591

Claim:
A method for synthesizing 1,2,4,5-tetra(4-pyridyl)benzene (TPB), comprising the following steps: (A) mixing an iron-containing compound, a nitrate-containing compound, oxalate acid, 4,4′-trimethylenedipiperidine (TMDP), H 3 PO 4 , and 2 to 8 mL of water to form a mixture; (B) heating the mixture and maintaining the mixture at 160° C. or above for a first predetermined time; (C) cooling the mixture; and (D) placing the mixture at room temperature for a second predetermined time, to obtain an organic amine dimmer; wherein the iron-containing compound is at least one iron-containing compound selected from a group consisting of Fe 2 O 3 , FeCl 3 , and Fe(NO 3 ) 3 .