Coupling Reactions of Functionalized Zintl Ions [E9Cd(C6H5)]3− (E = Sn, Pb) with Tributyltinhydride: Synthesis and Isolation of {Sn9CdSn[(CH2)3CH3]3}3−

Reaction of ethylenediamine solutions of K4E9 (E = Sn, Pb) with diphenylcadmium yielded the Cd(C6H5)-functionalized Zintl ions, closo-[E9Cd(C6H5)]3− (E = Sn (1); Pb (2)). Solution reactivity studies of 1 with tributyltinhydride in pyridine revealed that the cluster is capable of undergoing a coupling reaction to yield the tributyltin-functionalized cluster, closo-{Sn9CdSn[(CH2)3CH3]3}3− (3). In-situ monitoring of this reaction by 1H and 13C{1H} NMR spectroscopy reveals the formation of the tributyltin functionalized cluster anion in addition to free benzene. Species 13 were characterized in the solid-state as [K(2,2,2-crypt)]+ salts by single crystal X-ray diffraction and elemental analysis, while the presence of all three cluster anions in solution was confirmed by 1H and 13C{1H} NMR spectroscopy and electrospray mass-spectrometry.