Salt-like hydride selenides may be formed by heating selenium with a metal hydride in an oxygen-free capsule. For rare earth elements, this method works as long as selenium has enough oxidising power to convert a +2 oxidation state to a +3 state. So for europium and ytterbium it does not work as the monoselenide is more stable.[1]
One transition metal complex was formed from a lithium zirconium hydride complex in solution reacting with diphenylphosphine selenide.[2]
Properties
With rare earth elements there are two structure depending on the size of the metal ions. The large atoms form a 2H hexagonal anti-nickel arsenide structure, with hydrogen inserted into tetrahedral positions. A 1H hexagonal structure is found in rare earth elements from gadolinium to lutetium, and yttrium.[3]
^Folchnandt, Matthias; Rudolph, Daniel; Hoslauer, Jean-Louis; Schleid, Thomas (26 June 2019). "The rare earth metal hydride tellurides RE HTe ( RE =Y, La–Nd, Gd–Er)". Zeitschrift für Naturforschung B. 74 (6): 513–518. doi:10.1515/znb-2019-0060.