[Sb₁₁]³⁻ and [As₁₁]³⁻: Synthesis and Crystal Structure of Two New Ammoniates containing Trishomocubane‐like Polyanions

A S8‐like [Sb8]8− Zintl Anion in the Ammoniate [K17(Sb8)2(NH2)] · 17.5NH3

“…The two nearly identical [Sb 8 ] 8Ϫ rings have Sb-Sb bond lengths between 2.847(2) and 2.872(3) Å with a mean value of 2.861 Å , which corresponds well to the mean value of 2.849 Å for [Sb 5 ] 5Ϫ [8]. As is to be expected, the homoatomic bonds in antimony polyanions with a lesser charge-per-atom ratio like [Sb 11 ] 3Ϫ (mean value 2.803 Å [11,12]) or [Sb 7 ] 3Ϫ (mean value 2.82 Å [13]) are considerably shorter. This charge-induced effect is virtually nonexistent for the As 8 -containing complex anions mentioned above; the mean As-As bond lengths of [NbAs 8 ] 3Ϫ (2.434 Å [9]) and MoAs 8 2Ϫ 2.429 Å [10]) are exactly the same as those in [As 11 ] 3Ϫ (2.432 Å [12]) and [As 7 ] 3Ϫ (2.420 Å [14]).…”

“…As is to be expected, the homoatomic bonds in antimony polyanions with a lesser charge-per-atom ratio like [Sb 11 ] 3Ϫ (mean value 2.803 Å [11,12]) or [Sb 7 ] 3Ϫ (mean value 2.82 Å [13]) are considerably shorter. This charge-induced effect is virtually nonexistent for the As 8 -containing complex anions mentioned above; the mean As-As bond lengths of [NbAs 8 ] 3Ϫ (2.434 Å [9]) and MoAs 8 2Ϫ 2.429 Å [10]) are exactly the same as those in [As 11 ] 3Ϫ (2.432 Å [12]) and [As 7 ] 3Ϫ (2.420 Å [14]). This observation alone demonstrates that the structural properties of the As 8 ring in those complexes differ markedly from the properties expected for a free [As 8 ] 8Ϫ anion.…”

Zintl‐Ionen, Käfigverbindungen und intermetalloide Cluster der Elemente der 14. und 15. Gruppe

“…42, 107, 111–116, 129–132 In [K 17 (Sb 8 ) 2 (NH 2 )](NH 3 ) 17.5 (Abbildung 1 i)136 liegt eine S 8 ‐analoge kronenförmige [Sb 8 ] 8− ‐Einheit vor, und – wie den Tabellen 2 und 7 (siehe Anhang) zu entnehmen ist – sind auch die Trishomocuban(Ufosan)‐förmigen Anionen [Pn 11 ] 3− (Pn=P, As und Sb) unter den Polypniktiden weit verbreitet (Abbildung 1 l). 113, 117–121, 133, 134, 137…”

Simple access to ionic liquids and organic salts containing the phosphaethynolate (PCO−) and Zintl (Sb113−) anions

“…The bond length between the twofold and threefold bonded antimony atoms varies from 2.752(2) to 2.766(1) Å (respectively from 2.811(1) to 2.841(1) Å for the threefold bonded antimony atoms) and matches with known [Sb 11 ] 3À clusters ([Na(2,2,2-crypt)] + 3 [Sb 11 ] 3À ; 2.757 Å and 2.827 Å). 23 The crystals are stable for several months at room temperature in the mother liquid but decompose very quickly if they are removed from the solvent. The investigation of 8 by NMR spectroscopy showed partial decomposition of the cation and as a consequence decomposition of the cluster anion by deprotonation of the methyl group, resulting in the formation of a phosphorous ylide, which shows a singlet resonance at 20.48 ppm in the 31 P{ 1 H} NMR spectra.…”