Pentafluorophenylarsenic compounds

Abstract

The preparation of pentafluorophenylarsonous dichloride and bispentafluorophenylarsinous chloride is described. Their neutral hydrolysis affords (C₆F₅AsO)_n and [(C₆F₅)₂As]₂O respectively, whereas alkaline hydrolysis produces pentafluorobenzene quantitatively. Silver sulphide reacts with them to give (C₆F₅AsS)₄ and [(C₆F₅)₂As]₂S respectively, from which the respective chlorides are re-formed on treatment with mercuric chloride. Mercuration of (C₆F₅)₂AsCl and [(C₆F₅)₂As]₂S affords separable isomeric mixtures of [(C₆F₅)₂As]₂. Similar mixtures are obtained from (C₆F₅)₂AsCl and PH₃ or (CH₃)₃SiH. Mercuration of C₆F₅AsCl₂ gives the four-membered arsenic ring compound (C₆F₅As)₄.