*2.4. Preparation of Working Electrode*

Grinded crystal samples of compound **1** or **2** (10 mg) and acetylene black (3 mg) were dispersed uniformly in isopropanol (0.5 mL) containing 5 wt% Nafion under ultrasonic

conditions. A total of 50 μL of the suspension was drop-cast onto a piece of carbon cloth (1 cm2) and then dried slowly at room temperature.

#### *2.5. Cyclic Voltammetry Experiments*

Cyclic voltammetry experiments were performed in acetonitrile (10 mL) containing supporting electrolyte LiClO4 (1.0 mmol) and benzyl alcohol (0.5 mmol) under ambient conditions, and the scan rate was kept at 40 mV s<sup>−</sup>1. The cyclic voltammetry tests of **1** and **2** were performed using a three-electrode setup: carbon cloth modified by **1** or **2** as the working electrode, platinum plate electrode as the counter electrode, and Ag/Ag+ as the reference electrode.
