The ionic compound beryllium and iodine (BeI2) is very hygroscopic, reacting violently with water to form hydroiodic acid. It is very soluble in alcohol and also combines with ether to give a blue-colored complex. It is a strong electrolyte and dissolves a variety of halides; it readily combines with fluorine to give beryllium fluoride, with chlorine to give beryllium chloride and with bromine to yield beryllium bromide. It is also a strong base that readily iodinates carbonyl compounds, particularly aldehydes
It is insoluble in benzene, toluene and spirits of turpentine and slightly soluble in carbon disulphide. The crystalline compound is not attacked by cold tetrachloride of beryllium, but it is very sensitive to moisture. The iodide is a strong reducing agent and can be reduced with sodium, potassium or lithium metals. It also reduces with nitric acid to give the iodide salt of those metals or beryllium trifluoride.
The iodide can be reduced with hydrogen sulfide or cyanogen gas at elevated temperatures. It is insensitive to most other metal sulfides, but it reacts with magnesium at temperatures above 550 degC to yield beryllium iodide sulfide. It can be reacted with triphenylphosphine to convert primary, secondary, tertiary and benzylic alcohols to the corresponding iodides with excellent selectivity and inversion of configuration