Synthesis, structure and magnetic properties of lanthanide(III) complexes with new imidazole-substituted imino nitroxide radical
摘要:
Synthesis, characterization and magnetic properties of new lanthanide-radical complexes, [Ln(III)(hfac)(3)(IM2imH)] (Ln = Gd, Tb; IM2imH=2-(2-pyridyl)-4,5-dihydro-4,4,5,5-tetramethyl-1H-imidazolyl-1-oxy), are described. The molecular structure of the [Tb(hfaC)(3)(IM2imH)] has been determined by the X-ray diffraction. The magnetic susceptibility data for [Gd(hfaC)(3)(IM2imH)] show that the Gd-IM2imH magnetic interaction is antiferromagnetic with an exchange coupling constant J = -2.59 cm(-1) in contrast to the ferromagnetic interaction in most of Gd(III) complexes containing paramagnetic center, which will be examined in connection with planarity of the IM2imH chelate. (c) 2004 Elsevier B.V. All rights reserved.
A new method for the reduction of nitronyl nitroxides
摘要:
Reduction of nitronyl nitroxides using hexamethylenetetramine is a very convenient method for preparing the corresponding imino nitroxides and 2-imidazoline N-oxides. (C) 2003 Elsevier Ltd. All rights reserved.
A new approach to the synthesis of multispin compounds has been developed, namely, the simultaneous introduction of two different stable nitroxides (nitronyl nitroxide and imino nitroxide) in a reaction with a metal ion. An important characteristic of the new method is that nitronyl nitroxide and imino nitroxide introduced in the reaction with the metal are the products of different series; i.e., the