Heteroatomic Molecular Clusters Derived from Group 15 Zintl Ion Cages: Synthesis and Isolation of [M₂(HP₇)₂]²⁻ (M = Ag, Au), Two Novel Cluster Anions Exhibiting Metallophilic Interactions

Abstract

Ethylenediamine (en) solutions of K(3)P(7) and 2,2,2-crypt (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) were reacted with the homoleptic group 11 complexes [M(nbe)(3)][SbF(6)] (M = Ag, Au; nbe = norbornene) yielding two novel cluster anions, [M(2)(HP(7))(2)](2-), both of which were isolated in low crystalline yields as [K(2,2,2-crypt)](2)[M(2)(HP(7))(2)] (M = Ag (1) and Au (2)). Optimization of the reaction conditions by incorporation of a proton source (ammonium tetraphenylborate) and the replacement of the light-sensitive nbe adducts of silver and gold with the chloride salts MCl (M = Ag, Au) was found to greatly increase the yield and purity in which 1 and 2 were isolated. Compounds 1 and 2 were characterized by single crystal X-ray diffraction, electrospray ionization mass-spectrometry (ESI- MS), elemental analysis, and (1)H and (31)P NMR spectroscopy. Density functional theory (DFT) calculations on the cluster anions were also conducted.

Argentophilic Interactions

“…The molecular structure has been reproduced by DFT calculations. [331] 3.7.4. Double-Bridging with S,S-coordinating Ligands Eight-membered dimetallacycles are also readily obtained with difunctional S,S donors.…”

Argentophile Wechselwirkungen

“…Die Molekülstruktur konnte in DFT-Rechnungen reproduziert werden. [331] 3.7.4. Doppelte Verbrückung durch S,S-koordinierte Liganden Achtgliedrige Metallacyclen kçnnen auch leicht mit difunktionalen S,S-Donoren erhalten werden.…”

{[CuSn5Sb3]2−}2: A Dimer of Inhomogeneous Superatoms

“…[26] In [Ag(Sn 9 À Sn 9 )] 5À , [27] the Sn 9 cages are additionally connected upon oxidative coupling. There are also known compounds in which diatomic and triatomic transition metal units are stabilized by Zintl ion coordination, such as [Au 3 (Ge 9 ) 2 ] 5À and [Cd 2 (Pb 9 ) 2 ] 6À , [28] for Group 14, and [M 2 As 14 ] 4À (M = Pd, Au), [29] [Cu 2 (Pn 7 ) 2 ] 4À (Pn = P, As), [8] [M 2 (HP 7 ) 2 ] 2À (Ag, Au), [30] and [Sb 3 Au 3 Sb 3 ] 3À , [31] as examples for Group 15. In the case of 1, however, there is virtually no Cu À Cu bond.…”