Coupling reactions of functionalized Zintl ions [E9Cd(C6H5)]3- (E = Sn, Pb) with tributyltinhydride: synthesis and isolation of {Sn9CdSn[(CH2)3CH3]3}3-.

ABSTRACT

Reaction of ethylenediamine solutions of K(4)E(9) (E = Sn, Pb) with diphenylcadmium yielded the Cd(C(6)H(5))-functionalized Zintl ions, closo-[E(9)Cd(C(6)H(5))](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-{Sn(9)CdSn[(CH(2))(3)CH(3)](3)}(3-) (3). In-situ monitoring of this reaction by (1)H and (13)C{(1)H} NMR spectroscopy reveals the formation of the tributyltin functionalized cluster anion in addition to free benzene. Species 1-3 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 (1)H and (13)C{(1)H} NMR spectroscopy and electrospray mass-spectrometry.