Cs₅Mo₂₁S₂₃

Pentacaesium henicosamolybdenum tricosasulfur is isostructural with Cs₅Mo₂₁Se₂₃ and is the third member in the series M_2n-1Mo_6n+3X_6n+5 (M = Rb, Cs; X = S, Se, Te). Its crystal structure contains as the main building block an Mo₂₁S₂₃ cluster unit, the Mo core of which consists of six face-sharing Mo₆ octahedra. The decrease in the ionic radii of the chalcogen results in a shortening of the Mo-Mo intertriangle distances while the intratriangle ones do not change significantly. The shortest intercluster Mo-Mo distance also decreases from 3.342 (3) Å in Cs₅Mo₂₁Se₂₃ to 3.1687 (9) Å in Cs₅Mo₂₁S₂₃.

-1