Fluorocarbon-aluminium compounds. I. Reactions of some fiuorocarbon halides with lithium tetrahydroaluminate

Abstract

Treatment of solutions of lithium tetrahydroaluminate with bromopenta- fluorobenzene, C₆F₅Br, or iodopentafluorobenzene, C₆F₅I, yields perfluorophenyl-aluminium compounds. The thermally stable complex lithium tris(pentafluorophenyl)bromoaluminate, LiAl(C₆F₅)₃Br, has been isolated. Similar reactions between lithium tetrahydroaluminate and perfluoroalkyl iodides are discussed. These reactions are known to yield thermally unstable perfluoroalkyl-aluminium compounds, and the present paper reports an investigation of the possible use of solutions of these compounds as perfluoroalkylating reagents. Although perfluoro- alkyl groups can be transferred from aluminium to tin and lead, the reactions are complicated and cannot be considered as useful synthetic pathways to perfluoroalkyl-tin or -lead compounds.