Abstract
The synthesis of heteroatom analogues of the cyclopentadienyl anion Cp- is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono-, tri- and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4-triarsolyl and tetraarsolyl salts are unknown. Herein, we report on the synthesis of ...
Abstract
The synthesis of heteroatom analogues of the cyclopentadienyl anion Cp- is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono-, tri- and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4-triarsolyl and tetraarsolyl salts are unknown. Herein, we report on the synthesis of Cs[E3C2(trip)(2)] (1a: E=P; 1b: E=As; trip=2,4,6-triisopropylphenyl) and Cs[E4C(trip)] (2a: E=P; 2b: E=As). Compound 1b represents the first 1,2,4-triarsolyl and 2b the first tetraarsolyl anion. All salts are obtained in one-pot syntheses using E(SiMe3)(3), 2,4,6-triisopropylbenzoyl chloride and CsF. The products 1a2C(4)H(8)O(2), 2aEt(2)O and 2b3C(4)H(8)O(2) were characterized by X-ray structural analysis, which revealed planar heterocycles. Nucleus-independent chemical shifts (NICS) confirmed the aromaticity of these anions. Notably, compound 2aEt(2)O is only the second tetraphospholyl ligand which is structurally characterized.