(Me3Sn)2SbSb(SnMe3)2, 1∞-verknüpfte SbSb-Hanteln in einem thermochromen Distiban mit Schweratomgerüst

Synthesis, structure and dispersion interactions in bis(1,8-naphthalendiyl)distibine

Naph₂Sb₂1 was synthesized by a reaction of 1,8-dilithionaphthalene NaphLi₂ with SbCl₃ and its solid state structure is reported on. 1 shows intermolecular interactions in the solid state, which were studied by quantum chemical calculations with dispersion corrected density functional theory, supermolecular ab initio approaches and symmetry adapted perturbation theory. The same methods were employed to compare the solid state interactions in the crystal of 1 to those in real (for E = P) and hypothetical (for E = As and Bi) crystal structures of Naph₂E₂. Dispersion interactions were found to provide the most important stabilising contribution in all cases, seconded by electrostatic attraction between pnictogen atoms and π-systems of neighbouring naphthyl groups.

{[CuSn5 Sb3 ](2-) }2 : A Dimer of Inhomogeneous Superatoms

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.

Oligosilanylated Antimony Compounds

By reactions of magnesium oligosilanides with SbCl3, a number of oligosilanylated antimony compounds were obtained. When oligosilanyl dianions were used, either the expected cyclic disilylated halostibine was obtained or alternatively the formation of a distibine was observed. Deliberate formation of the distibine from the disilylated halostibine was achieved by reductive coupling with C8K. Computational studies of Sb-Sb bond energies, barriers of pyramidal inversion at Sb, and the conformational behavior of distibines provided insight for the understanding of the spectroscopic properties.