Metal Complexes of a Picolinate-Based Nitronyl Nitroxide Free Radical

被引:36
作者
Coronado, Eugenio
Gimenez-Saiz, Carlos [1 ]
Romero, Francisco M. [1 ]
Tarazon, Ana
机构
[1] Univ Valencia, FGUV, Inst Ciencia Mol, Poligon La Coma S-N, E-46980 Paterna, Spain
关键词
MOLECULAR MAGNETIC-MATERIALS; STABLE FREE-RADICALS; IMINO NITROXIDE; FERROMAGNETIC INTERACTIONS; NICKEL(II) COMPLEXES; GADOLINIUM(III) COMPLEXES; EXCHANGE INTERACTION; CHELATING NITRONYL; CRYSTAL-STRUCTURE; COPPER(II);
D O I
10.1021/ic802218j
中图分类号
O61 [无机化学];
学科分类号
070301 ; 081704 ;
摘要
A nitronyl nitroxide free radical containing an appended picolinate moiety was synthesized. The resulting tridentate ligand picNN forms neutral mononuclear metal complexes of formula [M(picNN)(2)]center dot 3H(2)O (M = Mn, Co, Ni, Zn). These compounds are isostructural and crystallize in the orthorhombic Pnna space group. The metal complexes have a C-2 symmetric structure, with the metal centers lying on the binary axis and surrounded by two equivalent picNN radicals. The magnetic properties of this family of compounds indicate the presence of very strong metal-radical exchange interactions, ranging from J(Ni-rad) = -193 cm(-1) to J(Mn-rad) = -98 cm(-1). Relatively weak (J(rad-rad) = -15 cm(-1)) through-space magnetic interactions between free radicals coordinated to the same metal center were also evidenced in the study of the diamagnetic zinc(II) complex. Complexation with Cu2+ affords the carboxylate-bridged tetranuclear copper(II) complex [Cu-4(picNN)(4)(H2O)(4)](ClO4)(4) center dot 4H(2)O having eight interacting S = 1/2 spins in a cyclic topology. The antiferromagnetic copper-radical exchange interaction (J(Cu-rad) = -268 cm(-1)) is one of the largest ever reported.
引用
收藏
页码:2205 / 2214
页数:10
相关论文
共 55 条
[21]   Magnetostructural studies of copper(II)-verdazyl radical complexes [J].
Gilroy, Joe B. ;
Koivisto, Bryan D. ;
McDonald, Robert ;
Ferguson, Michael J. ;
Hicks, Robin G. .
JOURNAL OF MATERIALS CHEMISTRY, 2006, 16 (26) :2618-2624
[22]   Systematic investigation of the nature of the coupling between a Ln(III) ion (Ln = Ce(III) to Dy(III)) and its aminoxyl radical ligands.: Structural and magnetic characteristics of a series of {Ln(organic radical)2} compounds and the related {Ln(Nitrone)2} derivatives [J].
Kahn, ML ;
Sutter, JP ;
Golhen, S ;
Guionneau, P ;
Ouahab, L ;
Kahn, O ;
Chasseau, D .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (14) :3413-3421
[23]   EXCHANGE INTERACTION IN POLYNUCLEAR COMPLEXES .1. PRINCIPLES, MODEL AND APPLICATION TO BINUCLEAR COMPLEXES OF CHROMIUM(III) [J].
KAHN, O ;
BRIAT, B .
JOURNAL OF THE CHEMICAL SOCIETY-FARADAY TRANSACTIONS II, 1976, 72 :268-281
[24]  
Kahn O., 1993, Molecular Magnetism
[25]   NITRONES .4. SYNTHESIS AND PROPERTIES OF A MONOCYCLIC ALPHA-DINITRONE [J].
LAMCHEN, M ;
MITTAG, TW .
JOURNAL OF THE CHEMICAL SOCIETY C-ORGANIC, 1966, (24) :2300-&
[26]   Synthesis, structures, and magnetic properties of a series of lanthanum(III) and gadolinium(III) complexes with chelating benzimidazole-substituted nitronyl nitroxide free radicals.: Evidence for antiferromagnetic GdIII-radical interactions [J].
Lescop, C ;
Belorizky, E ;
Luneau, D ;
Rey, P .
INORGANIC CHEMISTRY, 2002, 41 (13) :3375-3384
[27]   Synthesis, structures, and magnetic and optical properties of a series of europium(III) and gadolinium(III) complexes with chelating nitronyl and imino nitroxide free radicals [J].
Lescop, C ;
Luneau, D ;
Rey, P ;
Bussière, G ;
Reber, C .
INORGANIC CHEMISTRY, 2002, 41 (21) :5566-5574
[28]   An unprecedented asymmetric end-on azido-bridged copper(II) imino nitroxide complex: Structure, magnetic properties, and density functional theory analysis [J].
Li, Licun ;
Liao, Daizheng ;
Jiang, Zonghui ;
Mouesca, Jean-Marie ;
Rey, Paul .
INORGANIC CHEMISTRY, 2006, 45 (19) :7665-7670
[29]   Syntheses, crystal engineering, and magnetic property of a dicyanamide bridged three-dimensional manganese(II)-nitronyl nitroxide coordination polymer derived from a new radical [J].
Lin, HH ;
Mohanta, S ;
Lee, CJ ;
Wei, HH .
INORGANIC CHEMISTRY, 2003, 42 (05) :1584-1589
[30]   Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals [J].
Luneau, D ;
Rey, P .
COORDINATION CHEMISTRY REVIEWS, 2005, 249 (23) :2591-2611