六氰基金属酸盐分子化学：七核异双金属配合物；基态自旋态的控制

Hexacyanometalate molecular chemistry: heptanuclear heterobimetallic complexes; control of the ground spin state.

作者信息

Marvaud Valérie, Decroix Caroline, Scuiller Ariane, Guyard-Duhayon Carine, Vaissermann Jacqueline, Gonnet Florence, Verdaguer Michel

机构信息

Laboratoire de Chimie Inorganique et Matériaux Moléculaires, CNRS, UMR 7071, Université Pierre et Marie Curie, 75252 Paris Cedex 05, France.

出版信息

Chemistry. 2003 Apr 14;9(8):1677-91. doi: 10.1002/chem.200390192.

DOI:10.1002/chem.200390192

PMID:12698426

Abstract

Following a bottom-up approach to nanomaterials, we present a rational synthetic route from hexacyanometalates M(CN)(6) (M=Cr(III), Co(III)) cores to well-defined heptanuclear complexes. By changing the nature of the metallic cations and using a localised orbital model it is possible to control and to tune the ground state spin value. Thus, with M=Cr(III), d(3), S=3/2, three heptanuclear species were built and characterised by mass spectrometry in solution, by single-crystal X-ray diffraction and by powder magnetic susceptibility measurements, Cr(III)(CNbondM'L(n))(6) (M'=Cu(II), Ni(II), Mn(II), L(n)=polydentate ligand), showing spin ground states S(G)=9/2 [Cu(II)], with ferromagnetic interactions J(Cr,Cu)=+45 cm(-1), S(G)=15/2 [Ni(II)] and J(Cr,Ni)=+17.3 cm(-1), S(G)=27/2 [Mn(II)], with an antiferromagnetic interaction J(Cr,Mn)=-9 cm(-1), (interaction Hamiltonian H=-J(Cr,M) [S(Cr)Sigma(i)S(M)(i)], i=1-6). With M=Co(III), d(6), S=0, the heptanuclear analogues Co(III)(CN-M'L(n))(6) (M'=Cu(II), Ni(II), Mn(II)) were similarly synthesised and studied. They present a singlet ground state and allow us to evaluate the weak antiferromagnetic coupling constant between two next-nearest neighbours M'-Co-M'.

摘要

遵循纳米材料的自下而上方法，我们展示了一条从六氰基金属酸盐[M(CN)₆]³⁻（M = Cr(III)、Co(III)）核到定义明确的七核配合物的合理合成路线。通过改变金属阳离子的性质并使用局域轨道模型，可以控制和调节基态自旋值。因此，对于M = Cr(III)，d³，S = 3/2，构建了三种七核物种，并通过溶液中的质谱、单晶X射线衍射和粉末磁化率测量进行了表征，[Cr(III)(CN−M'Lₙ)₆]⁹⁺（M' = Cu(II)、Ni(II)、Mn(II)，Lₙ = 多齿配体），显示出自旋基态S(G) = 9/2 [Cu(II)]，具有铁磁相互作用J(Cr,Cu) = +45 cm⁻¹，S(G) = 15/2 [Ni(II)]且J(Cr,Ni) = +17.3 cm⁻¹，S(G) = 27/2 [Mn(II)]，具有反铁磁相互作用J(Cr,Mn) = -9 cm⁻¹，（相互作用哈密顿量H = -J(Cr,M) [S(Cr)ΣᵢS(M)ᵢ]，i = 1 - 6）。对于M = Co(III)，d⁶，S = 0，类似地合成并研究了七核类似物[Co(III)(CN−M'Lₙ)₆]⁹⁺（M' = Cu(II)、Ni(II)、Mn(II)）。它们呈现单重态基态，并使我们能够评估两个次近邻M'-Co-M'之间的弱反铁磁耦合常数。