Imidazole-substituted oxoverdazyl radical as a mediator of intramolecular and intermolecular exchange interaction.
The 3-(2'-imidazolyl)-1,5-dimethyl-6-oxoverdazyl radical (imvd(*)) and the corresponding tetrazane H3imvd were prepared and structurally characterized, the former as two different hydrates. Reaction of imvd(*) with [M(hfac)2] led to the formation of monometallic complexes [M(hfac)2(imvd(*))] (M = Ni and Mn). They were characterized by single-crystal X-ray diffraction. In the solid state, all four radical-containing compounds exhibit imidazole-oxoverdazyl pi stacking. Following the structural analysis, imvd(*) behaves as an antiferromagnetic (AF) coupled chain with J = -100 cm(-1) (H = -J summation operator SiS(i+1)). The magnetic behavior of [M(hfac)2(imvd(*))] complexes is interpreted with a four-coupled spin model with a metal ion radical intramolecular interaction (JMn = -62.5 cm(-1) and JNi = 193 cm(-1); H = -JSMSimvd) and an AF intermolecular interaction (JMn' = -12.6 cm(-1) and JNi' = -4.3 cm(-1)) related to imidazole-oxoverdazyl pi stacking.
Norel
Lucie
L
Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR 7071, IFR 2769, UPMC Univ. Paris 6, case 42, 4 place Jussieu, F75252 Paris cedex 05, France.
Pointillart
Fabrice
F
Train
Cyrille
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Chamoreau
Lise-Marie
LM
Boubekeur
Kamal
K
Journaux
Yves
Y
Brieger
Aaron
A
Brook
David J R
DJ