Nitronyl nitroxides containing tetrazole substituents and metal complexes with spin-labeled tetrazole

The first nitronyl nitroxides containing tetrazole substituents: sodium salt of 2-(1H-tetrazol-5-yl)-4,4,5,5-tetrametllyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl (Na(2)), 2-(1-methyl-1H-tetrazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl (3), and 2-(2-methyl-2H-tetrazol-5-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazol-3-oxide-1-oxyl (4) have been synthesized. The structures of 2-4 were confirmed by X-ray analysis. For 2, a tendency to form highly dimensional structures by interaction with transition metals has been found. Mn-II tends to form diamond-like packing with 2 using [Mn(H2O)(6)](2+) and [Mn(2)(3)](-) building blocks. Ni-II forms layered structures from the binuclear cations with the aid of the bridging nitroxide [En(2)Ni(2)NiEn(2)](3+) and H-bonded ClO4- groups. (C) 2003 Elsevier Science Ltd. All rights reserved.