Syntheses, Structures, and Spectroscopic Properties of Cobalt(III) Complexes Containing 3- or 4-Pyridyl-Substituted Nitronyl and Imino Nitroxide Ligands

Abstract

Several new cobalt(III) complexes incorporating 4,4,5,5-tetramethyl-2-(3-or 4-pyridyl)imidazolin-1-oxyl 3-oxide (NITnpy) (n = 3 or 4) or 4,4,5,5-tetramethyl-2-(3-or 4-pyridyl)-imidazolin-1-oxyl (IMnpy) have been prepared. The X-ray crystallographic analyses and the spectroscopic investigations have revealed that the nitronyl or imino nitroxides with the radical character are bound through the pyridyl-N atom to a Co III center. There are some influences from the radical unpaired electron toward the Co III complex moiety and those from the coordination of the Co III ion toward the

Crystal structure of chloronitrato-2-{2′-[(1′-methyl)benzimidazolyl]}- 4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxidemercury(II) – mercury(II)chloride, HgCl(NO3)(C15H19N4O2) · HgCl2

“…During the past decade, nitronyl nitroxide radicals (NITR) have been widely employed as molecular units in the design and synthesis of molecular magnetic materials [2][3][4], due to their exceptional stability and their rich chemistry. Al ot of studies on the magnetic properties of the nitronyl nitroxide and imino nitroxide radicals of metal complexes have been reported [5][6][7].…”

Crystal structure of diaquabis{2-[2'-(1'-methylbenzimidazolyl)]-4,4,5,5- tetramethylimidazoline-1-oxyl-3-oxide}mangan(II) bisperchlorate dihydrate, [Mn(H2O)2(C15H19N4O2)2](ClO4)2 · 2H2O

“…In many different types of organic radicals, research has focused on the nitronyl nitroxide radicals (NITR) family because of their flexibility and functionality [2,3]. Several investigations on the magnetic properties of the nitronyl nitroxide and imino nitroxide radicals of metal complexes have been reported [4][5][6][7][8]. …”

Crystal structure of 4,4,5,5-tetramethyl-2-(2-bithienyl)- imidazolidine-1,3-diol, C15H20N2O2S2

“…Nitronyl nitroxide (NN) radicals have attracted agreat deal of interest in the synthesis of purely organic magnetic materials and mixed metal-radical magnets [2][3][4]. Among the various approaches, stable organic nitronyl nitroxide radicals (NITR) play an important role as basic ligands due to their exceptional stability and their rich chemistry [5][6][7][8].…”