{[CuSn5Sb3]2−}2: A Dimer of Inhomogeneous Superatoms. Issue 39 (25th August 2016)

• Record Type: Journal Article
• Authors: Wilson, Robert J.; Broeckaert, Lies; Spitzer, Fabian; Weigend, Florian; Dehnen, Stefanie
• Is Part Of: Angewandte Chemie international edition. Volume 55:Issue 39(2016)
• Page Start: 11775
• Page End: 11780
• Publication Date: 2016-08-25
• Subjects: antimony -- cluster compounds -- copper -- DFT calculations -- tin; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201603455
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Reaction of the binary Zintl anion (Sn2 Sb2 ) 2− with the β‐diketiminato complex [LCu(NCMe)] (L=nacnac=[(N(C6 H3 i Pr2 ‐2, 6)C(Me))2 CH] − ) in ethylenediamine or DMF affords the ternary cluster dimer {[CuSn5 Sb3 ] 2− }2 (1 ) as its [K(crypt‐222)] + salt. The chemical formulation of 1 is supported by energy‐dispersive X‐ray spectroscopy (EDX) and quantum chemical calculations. Each monomeric part of the dimer represents a trimetallic "[CuSn5 Sb3 ] 2− " cluster, with an architecture in between a tricapped trigonal prism and a capped square antiprism. As shown by quantum chemical investigations, the presence of Sb atoms and, in particular, of Cu atoms in the cluster skeleton makes the monomeric unit behave like an inhomogeneous superatom, which clearly prefers to dimerize, thereby producing a relatively short, yet virtually non‐bonding Cu⋅⋅⋅Cu distance. Abstract : Like in a molecular "Oscar" made of britannia‐metal, Cu, Sn, and Sb atoms are combined in the heterometallic cluster anion {[CuSn5 Sb3 ] 2− }2 that was obtained by a reaction of (Sn2 Sb2 ) 2− with [nacnacCu(NCMe)]. It is shown by DFT calculations that as a result of the incorporation of the Cu atom, the monomeric units may be described as inhomogeneous superatoms, which are largely stabilized by dimerization—unlike isostructural and isoelectronic Sn9 2−, which is a homogeneous superatom.