Polymorphism in nickel phosphonates: synthesis of layered and microporous Ni(O3PCH2C(O)NH2)·H2O

Two new polymorphic nickel phosphonates have been prepared by a reaction between nickel acetate and diethyl cyanomethylphosphonate. The acidity of the nickel solution affects the hydrolysis of the phosphonate to produce the phosphonic acid in situ.