Isolated, Complex Zintl Molecules in the Gas Phase^†

Ternary and quaternary intermetallic molecules such as Cs₂InSb₃ and CsSnBiSb₂, respectively, can be detected in the vapor above the corresponding alloys by mass spectrometry. The composition of the compounds is in agreement with the Zintl-Klemm-Busmann concept, if one assumes that the alkali metal transfers an appropriate number of electrons to the elements of the third and fourth main groups in the Sb₄ tetrahedra, such that these elements become isoelectronic to Sb.