One compound, cacodyl cyanide, was particularly awful. Inorganic chemists discovered the properties of cacodyl as a ligand for transition metals. From it other compounds were made, such as cacodyl fluoride, chloride, et cetera. Cacodyl undergoes spontaneous combustion in dry air. It consisted mostly of dicacodyl (((CH)As)) and cacodyl oxide (((CH)As)O). Cacodyl is also the name of the functional group or radical (CH)As.