Binary interpnictogen compounds bearing diaryl bismuth fragments bound to all lighter pnictogens

Abstract

Multiple interpnictogen compounds with covalent single bonds between a diarylbismuth fragment and all lighter pnictogens were obtained from diarylhalido bismuthanes. This includes compounds with a rare Bi–As or Bi–Sb single bond.

Heavy Chains: Synthesis, Reactivity and Decomposition of Interpnictogen Chains with Terminal Diaryl Bismuth Fragments

“…The Bi−As distances are 276.53(5) and 276.87(6) pm, which is about 2 pm longer than in 2 Ph . This slight elongation of the Bi−As bond for the larger Mes group compared to the Ph substituent is consistent with compounds of the form Ar 2 BiP t BuR (Ar=Ph, Mes; R= t Bu, SiMe 3 ) [13] . The Bi−As−Bi angle is 91.58(1)° which is only slightly expanded compared to 2 Ph .…”

“…A Bi−As−As−Bi motive can only be found in one other literature known compound, (Cl(SiMe 3 ) 2 CHBi) 2 As) 2 , where an As 2 fragment is bound to four bismuth atoms [3] . The Bi−As bond length of 272.19(3) pm in 3 Ph , is slightly shorter than in compound 2 Ph but still fits well to the other described Bi−As bonds [3,5,13,24,25] . The As−As bond length of 243.42(6) pm is similar to model compounds like ( t BuAs) 4 (244.2(1)–244.4(1) pm) [26] or the before mentioned ((Me 3 Si) 2 CH)ClBi) 2 As) 2 (245.0(3) pm) [3] .…”

“…In a previous publication, we reported the synthesis of binary interpnictogen compounds, containing silyl functions. These were prepared from Ar 2 BiCl (Ar=Ph, Mes) and t BuE(SiMe 3 ) 2 (E=P, As) by elimination of trimethylsilyl chloride in α,α,α‐trifluorotoluene (TFT) and had the general formula Ar 2 Bi‐E t Bu(SiMe 3 ) (Ar=Ph, Mes; E=P, As) [13] . For further functionalization by trimethylsilyl chloride elimination, these were reacted with another equivalent of Ar 2 BiCl in TFT (Scheme 1).…”

“…The reductive cleavage of Bi−E (E=N, P, As, Sb) bonds under formation of a reduced bismuth species and formation of an E−E bond has been reported before. Examples include the reversible activation of P 4 by a dibismuthane under formation of a compound with a butterfly type structural motif, [1] the formation of hydrazines, diphosphanes or diarsanes from trisaminobismuthanes and secondary phosphanes or arsanes under precipitation of elemental bismuth, [14] or the equilibrium reaction of bismuthanyl stibanes [13] . In the formation of 3 Ph , a mechanism, where two Bi−As bonds are cleaved and a transient arsenidene fragment is transferred to another equivalent of 2 Ph is imaginable.…”

“…In a recent publication, we could show, that diarylbismuth chlorides are effective precursors for the synthesis of interpnictogen compounds bearing Bi−N, −P, −As, and even −Sb bonds [13] . We present here a systematic study of the preparation of interpnictogen compounds featuring terminal diarylbismuthanyl fragments and a chain of three pnictogen atoms by using the diarylbismuth platform.…”