CuCl2 . 2H(2)O reacts with 8-hydroxylquinoline (short as HQ) in two steps if the reactants are mixed in 1 : 2 molar ratio : first, it produces a new intermediate, Cu(HQ)Cl-2, and then the intermediate reacts with free 8-hydroxylquinoline and produces CuQCl. However, the same reactants can only give CuQCl or CuQ(2) in the methanol solution. Reasons that lead to those results are discussed.