**2. Materials and Methods**

*Crystals* **2021**, *11*, x FOR PEER REVIEW 2 of 13

#### **2. Materials and Methods** *2.1. Materials*

*2.1. Materials* DPA and TA were purchased from Tokyo Chemical Industry Co. Ltd. (Tokyo, Japan). All other analytical-grade solvents and reagents were commercially obtained and used DPA and TA were purchased from Tokyo Chemical Industry Co. Ltd. (Tokyo, Japan). All other analytical-grade solvents and reagents were commercially obtained and used without further purification.

#### without further purification. *2.2. Crystallization of DPA:TA Salt*
