Californium(II) iodide

Californium(II) iodide is a binary inorganic compound of californium and iodine with the formula.

Synthesis
It can be produced by reducing californium triiodide with hydrogen in a quartz thin tube at 570 °C:
 * 2CfI3 + H2 -> 2CfI2 + 2HI

Physical properties
The compound forms a dark purple solid. At slightly higher temperatures, it melts and reacts with the silica in the thin tube, producing CfOI.

Californium diiodide has two crystal structures, one is Cadmium(II) chloride-type crystal structure, stable at room temperature, with lattice parameters a = 743.4 ± 1.1 pm and α = 35.83 ± 0.07°; the other is metastable, of -type with lattice parameters a = 455.7 ± 0.4 pm and c  = 699.2 ± 0.6 pm. Californium diiodide has an absorption band in the wavelength range from 300 to 1100 nm, which proves the existence of Cf(II).