SYNTHESIS OF NEW LAMELLAR IRON(III) PHOSPHONATES

The behavior of phenylphosphonic acid toward FeOCl is presented as a pathway for the synthesis of lamellar iron(III) phosphonates, and the following adducts have been isolated: HFe(C6H5PO3H)4 and HFe(C6H6PO3)2•H2O. The quasi-one-dimensional structure of HFe(C6H5PO3H)4 has been determined by X-ray crystallography. The crystals are triclinic, space group with a = 14.968 (9) Å, 6 = 5.36 (1) Å, c = 8.678 (6) Å, α = 88.5 (1)°, β = 86.41 (6)°, γ = 89.6 (1)°, V = 694 (1) Å3, Z = 1. The final R and Rw values were 0.063 and 0.068, respectively. In acetone or toluene this kinetic compound gradually turns into HFe(C6H5PO3)2•H2O for which a structure close to that of α-ZrP is proposed. Three crystallographic forms of HFe(C6H5PO3)2•H2O have been obtained, differing from each other in the location of the water molecule in the layered structure. © 1990, American Chemical Society. All rights reserved.