Intercalation of a Nitronyl Nitroxide Radical Into Layered Inorganic Host: 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-Al-CO3 and Zn-Al-Cl) and the butanoxy derivative of lambda-zirconium phosphates. In all cases the intercalation procedure was successfully accomplished. The percentage of exchanged anions obtained was 27, 45, 40% for Mg-Al-LDH, Zn-Al-LDH and kZrPO(4)[O(CH2)(3)CH3]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.