1D Manganese(II) Derivatives of an Imidazole-Substituted Nitronyl Nitroxide. An Approach toward Molecular Magnetic Materials of High Dimensionality.
Extended linear complexes of manganese(II) with a bis-chelating nitronyl nitroxide ligand, 2-(2-imidazolato)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazolyl-3-oxide-1-oxy (NITIm), have been prepared where metallic and organic spin carriers alternate. Depending on the deprotonating agent, the solvent, and the counteranion, the species [Mn(NITIm)(H(2)O)(2)]CH(3)COO, 1, [Mn(NITIm)(DMSO)(2)]BPh(4), 2, [Mn(NITIm)(H(2)O)(ImH)]NO(3), 3, and [Mn(NITIm)(NITImH)]ClO(4), 4, have been obtained, which differ by the additional ligands completing the metal coordination sphere. Complexes 1-3 are cis isomers and 4 is found as the mer modification; in all compounds, one observes a regular alternation of Lambda and Delta metal environments. Their magnetic properties are similar, with Mn(II)-nitroxide interactions J approximately -45 cm(-)(1) (H = -2JS(i)().S(j)()), and they display weak ferromagnetic properties below 5 K. Canting of the manganese ions is responsible for these properties. Relevant crystallographic parameters are as follows: 1, space group Fdd2, a = 16.713(1), b = 40.111(3), c = 9.735(1), Z = 16; 2, space group Pca2(1), a = 30.328(3), b = 13.422(1), c = 9.589(1), Z = 4; 3, space group P2(1)/c, a = 9.787(2), b = 22.973(5), c = 9.671(2), beta = 117.32(3) degrees, Z = 4; 4, space group P2(1)/c, a = 9.761(2), b = 28.668(5), c = 9.941(2), beta = 96.07(3) degrees, Z = 4.
Fegy
Karine
K
Département de Recherche Fondamentale sur la Matière Condensée, Service de Chimie Inorganique et Biologique, Laboratoire de Chimie de Coordination (URA CNRS 1194), CEA-Grenoble, 17 rue des Martyrs, 38054 Grenoble Cédex 09, France, Laboratoire de Spectrométrie Physique (CNRS-UMR 5588), Université Joseph Fourier Grenoble 1, BP 87, 38402 Saint Martin d'Hères Cedex, France, and Centre de Recherche sur les Très Basses Températures, CRTBT-CNRS, BP166, 38042 Grenoble Cedex 09, France.
Luneau
Dominique
D
Belorizky
Elie
E
Novac
Miguel
M
Tholence
Jean-Louis
JL
Paulsen
Carley
C
Ohm
Thorsten
T
Rey
Paul
P