Synthesis and Crystal Structure of Two Members of a New Type of Layered Compound: Copper(II) Hydroxyphosphonates

Two original layered copper(II) hydroxyphosphonates Cu 2.5 (O 3 P(CH 2 ) 2 NH 3 )(OH) 2 (SO 4 ) (monoclinic P 2 1 / n (No. 14), a = 5.442(1) Å, b = 20.570(4) Å, c = 8.529(2) Å, β = 93.18(3)°, Z = 4) and Cu 2 (O 3 P(CH 2 ) 2 NH 2 )(OH)(NO 3 )· H 2 O (monoclinic P 2 1 (No. 4), a = 8.392(2) Å, b = 6.132(1) Å, c = 9.097(2) Å, β = 104.11(3)°, Z = 2) were prepared from copper sulfate or nitrate, (2-aminoethyl)phosphonic acid, and sodium hydroxide in water. In both cases, the anion of the starting copper salt was retained in the structure. For the first compound, the sulfate groups were part of the layer, while, for the second, the nitrate groups were present in the interlayer space, in a manner similar to that observed in layered double hydroxides.