A layered zinc hydroxide nitrate (Zn-5(OH)(8)(NO3)(2)center dot 2H(2)O) and a layered double hydroxide (Zn/Al-NO3) were synthesized by coprecipitation and doped with different amounts of Cu2+ (0.2, 1, and 10 mol%), as paramagnetic probe. Although the literature reports that the nitrate ion is free (with D-3h symmetry) between the layers of these two structures, the FTIR spectra of two zinc hydroxide nitrate samples show the C-2 nu symmetry for the nitrate ion, whereas the g(parallel to)/A(parallel to) value in the EPR spectra of Cu2+ is high. This fact suggests bonding of some nitrate ions to the layers of the zinc hydroxide nitrate. The zinc hydroxide nitrate was used as matrix in the intercalation reaction with benzoate, o-chlorobenzoate, and o-iodobenzoate ions. FTIR spectra confirm the ionic exchange reaction and the EPR spectroscopy reveals bonding of the organic ions to the inorganic layers of the zinc hydroxide nitrate, while the layered double hydroxides show only exchange reactions. (C) 2007 Elsevier Inc. All rights reserved.