Rajendiran T. M., Mathonière Corine, Golhen Stéphane, Ouahab Lahcène, Kahn Olivier
Laboratoire des Sciences Moléculaires, Institut de Chimie de la Matière Condensée de Bordeaux, UPR CNRS No. 9048, 33608 Pessac, France, and Laboratoire de Chimie du Solide et Inorganique Moléculaire, UMR No. 6511, Université de Rennes I, 35042 Rennes, France.
Inorg Chem. 1998 Jun 1;37(11):2651-2654. doi: 10.1021/ic9708531.
The goal of this work was to design a ferromagnetically coupled Mn(2+)Ni(2+) species. For this, we attempted to combine nitro-nitrito and end-on azido bridges which are both known to be ferromagnetic couplers. This has led us to the compound of formula Mn(N(3))(4)Ni(en)(2)NO(2) (en = ethylenediamine). The crystal structure has been solved at room temperature. The compound crystallizes in the monoclinic system, space group C2, with a = 12.631(14) Å, b = 15.636(2) Å, c = 13.43(2) Å, beta = 90.14(6) degrees, and Z = 4. The structure consists of two very similar but crystallographically independent neutral trinuclear units with a MnNi(2) isoceles triangular shape. The Mn and Ni atoms are doubly bridged by an end-on azido and a nitro-nitrito (with respect to Ni and Mn, respectively) group. Both the temperature dependence of the magnetic susceptibility and the field dependence of the magnetization at 2 K have been investigated and have revealed Mn(2+)-Ni(2+) ferromagnetic interactions, which give rise to an S = (9)/(2) ground state for the triad. The quantitative interpretation of these magnetic properties has given an interaction parameter J between Mn(2+) and Ni(2+) ions equal to 1.4(1) cm(-)(1) (H = -JS(Mn)().(S(Ni1)() + S(Ni2)()). The electronic absorption spectrum has been recorded at various temperatures down to 20 K and interpreted.
这项工作的目标是设计一种铁磁耦合的Mn(2+)Ni(2+)物种。为此，我们尝试将已知为铁磁耦合剂的硝基-亚硝酸根和端基叠氮桥结合起来。这使我们得到了化学式为Mn(N(3))(4)Ni(en)(2)NO(2)的化合物（en = 乙二胺）。其晶体结构已在室温下解析。该化合物结晶于单斜晶系，空间群为C2，a = 12.631(14) Å，b = 15.636(2) Å，c = 13.43(2) Å，β = 90.14(6)°，Z = 4。结构由两个非常相似但晶体学上独立的中性三核单元组成，呈MnNi(2)等腰三角形形状。Mn和Ni原子分别通过一个端基叠氮和一个硝基-亚硝酸根（分别相对于Ni和Mn）基团进行双桥连。研究了磁化率的温度依赖性以及2 K时磁化强度的磁场依赖性，揭示了Mn(2+)-Ni(2+)铁磁相互作用，这导致该三元组的基态S = (9)/(2)。对这些磁性性质的定量解释给出了Mn(2+)和Ni(2+)离子之间的相互作用参数J等于1.4(1) cm(-)(1)（H = -JS(Mn)().(S(Ni1)() + S(Ni2)())）。已记录了在低至20 K的不同温度下的电子吸收光谱并进行了解释。
