AbstractReactions of (NH4)2MS4, AgBr and CuBr in γ‐methylpyridine produced one new compound, [MS4Cu4(γ‐MePy)8][M6O19] (1, M = W;2, M = Mo), of which 1 was characterized by single crystal X‐ray analysis. The crystal data: orthorhombic,Pbcn, a =15.434(4),b= 16.732(2), c = 28.657(7) Å,V= 7400.8(8) Å3,Z=4, R = 0.072 for 3121 independent data. The compound is the first example which contains both polyoxotungstate anion and heteropolynuclear cluster cation. In the structure of the cation four edges of the tetrahedral WS2−4core are coordinated by four copper atoms, giving a WS4Cu4aggregate of approximateD2hsymmetry. The differences between the reaction of Cu+with MS2−4and that of Ag+ with MS2−4in pyridine and its derivative