CH3NH3I was synthesized according to the reported method
[43]. A hydriodic acid (15 mL, 57 wt% in water) was reacted with methylamine (16 mL, 40% in methanol) in a 100 mL round-bottom
flask at 0 °C for 2 h. The precipitate was recovered by putting the
solution on a rotary evaporator and carefully removing the solvent
at 65 °C for 1 h. The generated yellowish powder was dissolved in
ethanol, recrystallized from diethyl ether, and finally dried at 70 °C in
a vacuum over for 24 h