Intercalation of a nitronyl nitroxide radical into layered inorganic hosts.: Preparation and physico-chemical characterization

The synthesis of new intercalation compounds obtained introducing the organic radical 2-(4-carboxyphenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-1-oxyl-3-oxide (NITpBAH) in layered inorganic hosts via topotactic anion exchange reactions or exchange of anionic ligands is presented. Three different inorganic hosts were employed, two LDH-phases (Mg&z.sbnd;Al&z.sbnd;CO3 and Zn&z.sbnd;Al&z.sbnd;Cl) and the butanoxy derivative of λ-zirconium phosphates. In all cases the intercalation procedure was successfully accomplished. The percentage of exchanged anions obtained was 27, 45, 40% for Mg&z.sbnd;Al&z.sbnd;LDH, Zn&z.sbnd;Al&z.sbnd;LDH and λ-ZrPO4[O(CH2)3CH3]DMSO, respectively. The magnetic properties of the intercalated compounds were measured with a SQUID magnetometer and compared to those of a polycrystalline powder of the pure radical. The intercalation process does not change the nature of magnetic intermolecular interactions which remain antiferromagnetic but reduces their magnitude. [Copyright &y& Elsevier]