A surprise landing on the terra incognita of macrocyclic dibridgehead diorganoarsines: syntheses, structures, and reactivities

Abstract

Reactions of trans-[Fe(CO)₂(NO)(As((CH₂)_n)₃As)]⁺ BF₄⁻ (n = 10, 12, 14) and Bu₄N⁺ Cl⁻ afford the title compounds As((CH₂)_n)₃As, which upon reaction (n = 14) with MCl₂ (M = Pt, Ni), Rh(CO)(Cl), and Fe(CO)₃ sources reconstitute cage like complexes trans-ML_n(As((CH₂)₁₄)₃As). Reactions with H₂O₂ and BH₃ give the corresponding arsine oxides and boranes. Crystal structures of metal-free species reveal out,out isomers, but cage complex formation is proposed to entail homeomorphic isomerization to in,in isomers with endo directed lone pairs.