Low-Temperature Synthesis of Zintl Compounds with a Single-Source Molecular Precursor

Abstract

Thermolysis of the heterobimetallic phosphinidene complex [Sb(PCy)3]2- Li6.6HNMe2 (Cy = C6H11) at 303 to 313 kelvin gives Zintl compounds containing (Sb7)3- anions. The complex thus constitutes a stable molecular single-source precursor to Zintl compounds and provides a potential low-temperature route to photoactive alkali metal antimonates. The new chemical reaction involved, which is driven thermodynamically by the formation of P-P bonds, has implications in the low-temperature synthesis of other technologically important materials (such as gallium arsenide).

Synthesis, Structure, and Reactivity of Ga‐Substituted Distibenes and Sb‐Analogues of Bicyclo[1.1.0]butane

“…Wright et al. reported on the synthesis of the Zintl compound [Sb 7 Li 3 ⋅6 HNMe 2 ] by controlled thermolysis reaction of {[Sb(PCy) 3 ] 2 Li 6 ⋅6 HNMe 2 } in toluene at low temperature (40 °C), whereas in recent years Kloo, Burford, and Weigand et al. established reductive catenation reactions for the synthesis of Group 15 polycations…”

Formation and Rearrangement of SnII Phosphanediide Cages

“…This intrigued us, as previous studies have shown that heterometallic group 15/alkali metal phosphanediides compounds (e.g., [12] ) decompose into Zintl ions and metallic alloys. [13] As illustrated in Scheme 6, this process occurs through heterocyclic anions of the type [(RP) m E] À and is driven by the thermodynamics of P À P single-bond formation. We wondered whether similar chemistry was occurring in the thermal decomposition of 1 a-c.…”

“…Solid 1 a , 1 b and 1 c are relatively stable at room temperature under dry, O 2 ‐free N 2 for days, decomposing only slowly at this temperature to give metallic‐looking residues. This intrigued us, as previous studies have shown that heterometallic group 15/alkali metal phosphanediides compounds (e.g., [{Sb(PCy) 3 } 2 (Li ⋅ NHMe 2 ) 6 ]12) decompose into Zintl ions and metallic alloys 13. As illustrated in Scheme , this process occurs through heterocyclic anions of the type [(RP) m E] − and is driven by the thermodynamics of PP single‐bond formation.…”

Formation and Structure of the [(1,2‐C6H4P2Sb)2]4− Ion: Implications for an Extended Family of Isoelectronic Main‐Group Radicals

“…Lithiation of 1,2‐(PH 2 ) 2 C 6 H 4 (1 equiv) with n BuLi (2 equiv) in tmeda (tmeda=Me 2 NCH 2 CH 2 NMe 2 ) followed by reaction with Sb(NMe 2 ) 3 (0.67 equiv) gives [Li(tmeda) 2 ] + [1,2‐C 6 H 4 P 2 Sb] − ( 1 ) after crystallization from THF/tmeda. However, black crystals of [{1,2‐C 6 H 4 P 2 Sb} 2 {Li(tmeda)} 4 ] ( 2 )6 are obtained if this reaction is undertaken in toluene and the product crystallized from toluene/tmeda. Compound 2 presumably arises from one‐electron reduction of the 6π‐aromatic anion of 1 (Scheme ).…”