Structures and magnetic properties of one-dimensional copper(II) complexes bridged with diazaaromatic rings
摘要:
Seven kinds of polynuclear complexes of [Cu(hfac)(2)] (Hhfac = 1,1,1,5,5,5-hexafluoropentane-2,4-dione) with diazaaromatic rings have been prepared. The crystal structures of [{Cu(hfac(mu-L)}(n)] (L = 2,5- and 2,6-dimethylpyrazines, propylpyrazine (prpyz), quinoxaline, phenazine, 4,6-dimethylpyrimidine, and 1,6-naphthyridine) have been determined. These complexes consist of a one-dimensional chain structure, and the geometry around the copper ion is approximately an octahedral structure. The relations between the magnetic properties and coordination structure were discussed from the magnetic measurements. In the mu-prpyz complex, one nitrogen atom is coordinated to a copper ion at an axial position, and at the same time the other coordinated at an equatorial site of a neighboring copper ion. This complex showed antiferromagnetic interaction with J/k(B) = -0.086(3) K estimated from the Bonner-Fisher model. Weak magnetic interaction is caused by the somewhat long Cu-N distances due to the steric effect from the bridging ligands. (c) 2006 Elsevier Ltd. All rights reserved.
Shift of stereochemical nonrigidity from coordination units to polymethylene fragments in heterospin copper(II) hexafluoroacetylacetonate complexes with nitronyl nitroxide biradicals
作者:G. V. Romanenko、S. E. Tolstikov、E. V. Tretyakov、S. V. Fokin、V. N. Ikorskii、V. I. Ovcharenko
DOI:10.1007/s11172-007-0279-6
日期:2007.9
heterospin complex [Cu(hfac)2]2L6 and the layer-polymeric heterospin complexes [Cu(hfac)2]2L10 and [Cu(hfac)2]2L12} [Cu(hfac)2(PriOH)2], respectively. In the solid state of these compounds, the stereochemicalnonrigidity is manifested as a deformation of the polymethylene fragments-(CH2)n-.
Structures of Anhydrous and Hydrated Copper(II) Hexafluoroacetylacetonate
作者:Andrew W. Maverick、Frank R. Fronczek、Emily F. Maverick、Damon R. Billodeaux、Zuzanna T. Cygan、Ralph A. Isovitsch
DOI:10.1021/ic020448w
日期:2002.12.1
Crystal structure analyses are reported for anhydrouscopper(II) hexafluoroacetylacetonate (Cu(hfac)(2)) and for two of its hydrates. The anhydrous compound (Cu(hfac)(2), 1: P1; at 100 K, a = 5.428(1), b = 5.849(1), c = 11.516(3) A; alpha = 81.47(2), beta = 74.57(2), gamma = 86.96(2) degrees; Z = 1) contains centrosymmetric square-planar complexes with close intermolecular Cu.F contacts. The geometry
Cu(hfac)2 Complexes with Nitronyl Ketones Structurally Mimicking Nitronyl Nitroxides in Breathing Crystals
作者:Evgeny V. Tretyakov、Galina V. Romanenko、Sergey L. Veber、Matvey V. Fedin、Aleksey V. Polushkin、Anastasia O. Tkacheva、Victor I. Ovcharenko
DOI:10.1071/ch14422
日期:——
target nitronyl ketones. An X-ray diffraction analysis of the nitronyl ketones confirms that their structural characteristics are close to those of the corresponding nitronylnitroxides. Moreover, upon reaction with Cu(hfac)2, diamagnetic nitronyl ketones form polymer-chain complexes with a ‘head-to-tail’ motif and a structure similar to their analogues containing paramagnetic nitronylnitroxides. Finally
Fluorinated β-Diketonates of the First Row Divalent Transition Metals: New Approach to the Synthesis of Unsolvated Species
作者:Haitao Zhang、Bo Li、Jinyu Sun、Rodolphe Clérac、Evgeny V. Dikarev
DOI:10.1021/ic801320p
日期:2008.11.3
solid-state route for the preparation of metal beta-diketonates in their unsolvated forms has been suggested. Four new first row divalent transition metal beta-diketonates, M(hfac)2 (M = Mn (1), Fe (2), Co (3), and Ni (4); hfac = hexaluoroacetylacetonate), have been isolated in quantitative yield. Compounds 1-3 have been obtained by comproportionation reaction between the corresponding M(hfac)3 and
EPR study on ligand-exchange reaction between bis(diethyldiselenocarbamato)copper(II) and some bis(acetylacetonato)copper(II) complexes
作者:Anna Dimitrova、Christina Taseva、Nicola D. Yordanov
DOI:10.1016/j.saa.2007.09.031
日期:2008.10
The paper is a study on the formation and properties of mixed-chelate copper(II) complexes, in which one ligand is strongly covalently bound diselenocarbamate (dsc), and the other belongs to a series of differently substituted acetylacetonates (acac), all forming weak covalent bonds. Thenoyltrifluoro- and trifluoro- substituted acetylacetonates only partly form mixed-chelate complexes, stable in toluene