in tetrahydrofuran (N2); molar ratio of Ho:I2 2:3; clear THF soln. of triiodide obtained by filtration or decanting;

in water evapn. (water bath);

in tetrahydrofuran (N2); molar ratio of Ho:I(CH2)2I 2:3; clear THF soln. of triiodide obtained by filtration or decanting;

in neat (no solvent) mixt. of metal and I2 was heated to the deflagration point of the mixt. in vac.; excess of I2 was evacuated, tube was filled with Ar, solidified metal part was removed, elem. anal.; metal triiodide was deposited on the wall of tube;

byproducts: NH3, H2O; 290-400°C, 1 h;