[Pb9CdCdPb9]6−: A Zintl cluster anion with an unsupported cadmium–cadmium bond

Abstract

Reaction of an ethylenediamine solution of the intermetallic Zintl phase K₄Pb₉ with dimesitylcadmium yielded the dimeric Zintl ion [Pb₉Cd–CdPb₉]⁶⁻ in low crystalline yield. The cluster anion exhibits a Cd–Cd bond and was structurally characterised by single crystal X-ray diffraction in [K(2,2,2-crypt)]₆[Cd₂Pb₁₈]·2en (1). DFT was also used to explore the bonding in the hexa-anionic cluster.