Hexacyanidometalate molecular chemistry, part III: di-, tri-, tetra-, hexa- and hepta-nuclear chromium-nickel complexes: Control of spin, structural anisotropy, intra- and inter-molecular exchange couplings
Hexacyanidometalate molecular chemistry, part III: di-, tri-, tetra-, hexa- and hepta-nuclear chromium-nickel complexes: Control of spin, structural anisotropy, intra- and inter-molecular exchange couplings
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DOI：
10.1016/j.ica.2008.03.045
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发表时间：
2008-09
影响因子：
2.8
通讯作者：
F. Tuyéras;A. Scuiller;C. Duhayon;M. Hernández-molina;F. D. Biani;M. Verdaguer;T. Mallah;W. Wernsdorfer
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文献类型：
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作者：
F. Tuyéras;A. Scuiller;C. Duhayon;M. Hernández-molina;F. D. Biani;M. Verdaguer;T. Mallah;W. Wernsdorfer
合成了9个μ-氰基桥联多核配合物[Cr(CN)n(CNNiL)6−n]m+(n=0-5，L为五齿配体)：CrNi，5个CrNi2，CrNi3，CrNi5和CrNi6。通过红外光谱、质谱学和X-射线结晶学对化合物进行了表征。研究了它们的磁性，评价了它们的自旋和各向异性以及分子内和分子间的交换耦合。自旋态从5/2到15/2(铁磁相互作用)变化，有效各向异性因子从0到0.5 cm−1。实验上，μ-氰基桥自旋载流子之间的交换耦合从+4.5到+18.3 cm−1随着C-N-Ni角的增加而变化。一项计算研究允许提出磁结构关联和合理的最相关的特征之间的交换作用的铬(III)(T2g3)和镍(Ii)(Eg2)通过氰基桥。为了减少分子间的相互作用，用共结晶的方法成功地将铬(III)-镍(II)化合物与等效钴(III)-镍(II)化合物进行了稀释。
Nine μ-cyanido bridged polynuclear complexes, [Cr(CN)n(CNNiL)6−n]m+, (with n=0–5 and L=pentadentate ligand), were synthesised: CrNi, five CrNi2, CrNi3, CrNi5and CrNi6. The compounds have been fully characterised by IR spectroscopy, mass spectrometry and X-ray crystallography. Their magnetic properties have been studied and the spin and the anisotropy values as well as the intra- and inter-molecular exchange couplings evaluated. The spin state varies from 5/2 to 15/2 (ferromagnetic interaction) and the effective anisotropic factor varies from 0 to 0.5cm−1. Experimentally, the exchange coupling between the μ-cyanido bridged spin carriers Cr(III) and Ni(II) varies from +4.5 to +18.3cm−1increasing with the C–N–Ni angle. A computational study allows to propose a magneto structural correlation and to rationalise the most relevant features of the exchange interaction between Cr(III) (t2g3) and Ni(II) (eg2) through a cyanido bridge. In order to decrease the intermolecular interactions, a dilution of the chromium(III)–nickel(II) compounds with the equivalent cobalt(III)–nickel(II) has been successfully performed by co-crystallisation.