The reaction of Rb4Sn4 with ZnPh2 in liquid ammonia in the presence of [2.2.2]-cryptand yielded crystals of Rb6[(η(2)-Sn4)Zn(η(3)-Sn4)]·5NH3, which could be characterized by single crystal X-ray diffraction. This is the first example of a successful solution reaction of the highly charged tetrahedral Sn4(4-) anions. The homoleptic [E4ZnE4](6-) complex (E = tetrel element) was previously known only for E=Ge and Si/Ge.