New Paramagnetic Re(II) Compounds with Nitrile and Cyanide Ligands Prepared by Homolytic Scission of Dirhenium Complexes
作者:Eric J. Schelter、Jitendra K. Bera、John Bacsa、José Ramón Galán-Mascarós、Kim R. Dunbar
DOI:10.1021/ic020661s
日期:2003.7.1
The preparation and characterization of three new paramagnetic complexes of the 17-electron Re(II) ion are reported. The salts [Re(triphos)(CH(3)CN)(3))][X](2), X = [BF(4)](-) (1), [PF(6)](-) (2), and [Et(4)N][Re(triphos)(CN)(3)] (3) were prepared by homolytic cleavage of the Re-Re bond in [Re(2)(CH(3)CN)(10)][BF(4)](4) or by disruption of the chlorine bridges in [(triphos)Re(mu-Cl)(3)Re(triphos)]Cl
A Family of Mixed-Metal Cyanide Cubes with Alternating Octahedral and Tetrahedral Corners Exhibiting a Variety of Magnetic Behaviors Including Single Molecule Magnetism
作者:Eric J. Schelter、Ferdi Karadas、Carolina Avendano、Andrey V. Prosvirin、Wolfgang Wernsdorfer、Kim R. Dunbar
DOI:10.1021/ja0683281
日期:2007.7.1
processes. The [MnIICl}4ReII(triphos)(CN)3}4] complex exhibits single molecule magnetism with a fast tunneling relaxation process observed at H = 0 determined by micro-SQUID magnetization measurements. A comparative evaluation of the magnetic properties across the series reveals that the compounds exhibit antiferromagnetic coupling between the metal ions, except for [NiIICl}4ReII(triphos)(CN)3}4] that
一系列结构相关的 Re(II) 和 3d 金属离子 [MX}4Re(triphos)(CN)3}4] (M = Mn, Fe, Co, Ni, Zn; X = Cl、I、-OCH3) 已被制备,并对其磁性和电化学性质进行了探测,以评估改变 3d 金属离子身份的影响。团簇的电化学揭示了几种基于铼的氧化和还原过程,其中一些会导致团簇碎裂。对于铁同系物观察到最丰富的电化学,其在静息电位下以 Re(I)/Fe(III) 簇存在,并表现出六个清晰的单电子可逆氧化还原电对和两个紧密间隔的单电子准可逆过程. [MnIICl}4ReII(triphos)(CN)3}4] 复合物表现出单分子磁性,在 H = 0 下观察到快速隧道弛豫过程,由微 SQUID 磁化测量确定。对整个系列磁性能的比较评估表明,除了 [NiIIICl}4ReII(triphos)(CN)3}4] 显示铁磁行为外,这些化合物在金属离子之间表现出反铁磁耦合。尽管
Molecular Cube of Re<sup>II</sup> and Mn<sup>II</sup> That Exhibits Single-Molecule Magnetism
作者:Eric J. Schelter、Andrey V. Prosvirin、Kim R. Dunbar
DOI:10.1021/ja047088r
日期:2004.11.1
A pseudocubic, paramagnetic cluster of ReII and MnII, [MnCl}4Re(triphos)(CN)3}4], has been prepared, and its magnetic properties have been investigated. Antiferromagnetic coupling is observed between the "S = 1/2" ReII and S = 5/2 MnII centers resulting in an effective S = 8 ground state. AC susceptibility studies reveal that the molecule is a single-molecule magnet with an effective barrier for magnetization reversal of Ueff = 8.8 cm-1.