Ternary Lamellar Compounds of Graphite with Aluminum Bromide and Bromine

Abstract

Abstract Graphite was allowed to react with binary reactants of aluminum bromide and bromine. The formation of ternary lamellar compounds was observed. A change in the activity of the reactants in the system gave three compounds I, II, and III with different contents of aluminum bromide and bromine. Compound I, obtained as the reaction product of graphite with the solution of bromine saturated with aluminum bromide, has a composition of C9AlBr3·Br2, and a lamellar structure of the first stage with Ic of 10.24 Å. Compound II, which has the lowest bromine content, has a composition of C24AlBr3·Br0.3 and a lamellar structure of the second stage with Ic of 13.35 Å. Compound III, obtained at a bromine activity higher than that for compound I, has a non-stoichiometric composition of about C5–6Br(AlBr3)0.2, and a structure of the second stage with Ic from 13.58 to 13.72 Å. The phase diagram of the ternary system was derived. Compounds I and III have higher bromine contents than C8Br, which is the saturation compound of graphite-bromine system. This is supposed to be due to the stabilization of bromine by the coexistence of aluminum bromide.