Cesium Platinide Hydride 4Cs2Pt•CsH: An Intermetallic Double Salt Featuring Metal Anions

With Cs9Pt4H a new representative of ionic compounds featuring metal anions can be added to this rare-membered family. Cs9Pt4H exhibits a complex crystal structure containing Cs+ cations, Pt2- and H- anions. Being a red, transparent compound its band gap is in the visible range of the electromagnetic spectrum and the ionic type of bonding is confirmed by quantum chemical calculations. This cesium platinide hydride can formally be considered as a double salt of the alloy cesium-platinum, or better cesium platinide, Cs2Pt, and the salt cesium hydride CsH according to Cs9Pt4H equivalent to 4Cs2Pt center dot CsH.