Product Short Description: METHYLAMMONIUM CHLORIDE FOR SYNTHESIS Product Description: It is an ammonium salt composed of methylamine and hydrogen chloride. ... Methylammonium iodide is the most commonly used, whereas using the chloride instead of, or as minor substituent to, the iodide provides the ability to tune the absorption, conductivity, and apparent bandgap. It is an ammonium salt composed of methylamine and hydrogen chloride. ... Methylammonium iodide is the most commonly used, whereas using the chloride instead of, or as minor substituent to, the iodide provides the ability to tune the absorption, conductivity, and apparent bandgap.