Departamento de Química Inorgánica, Universidad de La Laguna, c/o Astrofísico Francisco Sánchez s/n, 38206 La Laguna, Spain.
Inorg Chem. 2010 Aug 16;49(16):7478-90. doi: 10.1021/ic100796e.
Two new molecule-based materials of formulas 3D-{K(H(2)O)(6)K(18-crown-6)[MnCu(3)(Hmesox)(3)].5.25H(2)O} (1) and 3D-{(Ph(4)P)(2)[MnCu(3)(Hmesox)(3)Cl].3.5H(2)O} (2) have been prepared from a tricopper(II) secondary building unit (SBU), Cu(3)(Hmesox)(3) (H(4)mesox = mesoxalic acid, 2-dihydroxymalonic acid). Compound 1 is obtained by means of the reaction of the SBU with manganese(II) acetate in the presence of potassium cations and the 18-crown-6 ether, whereas compound 2 is obtained by means of the reaction of the SBU with manganese(II) acetate in the presence of Ph(4)PCl. The MnCu(3)(Hmesox)(3) and MnCu(3)(Hmesox)(3)Cl moieties in compounds 1 and 2, respectively, yield chiral 3-connected three-dimensional (3D) anionic (10,3)-a (srs, SrSi(2)) nets. In the cubic and centrosymmetric structures (Pa3) of 1, two inversion-symmetry-related anion nets interpenetrate to a racemic structure. The Ph(4)P(+) cations in 2 are organized in a supramolecular (10,3)-a net through the 6-fold phenyl embrace. In 2, both the cationic and anionic nets are homochiral and enantiopure with opposite handedness and form interpenetrating supramolecular and covalent (10,3)-a nets in the noncentrosymmetric Sohncke space group P 2(1)2(1)2(1). Both compounds display ferrimagnetic interaction with long-range magnetic ordering below 2.5 and 15.2 K for 1 and 2, respectively. A dehydrated phase of 2 exhibits a T(c) of 21.8 K. The saturation of magnetization, M(S), indicates two different ground states, S = (1)/(2) and (3)/(2), for the tricopper(II) units in 1 and 2, respectively. The different spin states of the tricopper(II) unit in 1 and 2 has been explained by means of a density functional theory (DFT) study performed in the Cu(3)(Hmesox)(3) and Cu(3)(Hmesox)(3)Cl fragments, for 1 and 2, respectively. A further DFT study has allowed one to analyze the structural parameters that lead to the different spin ground states for the trinuclear units in both compounds.
已制备了两个基于分子的新材料，公式为 3D-{(Ph4P)2[MnCu3(Hmesox)3Cl]}。3.5H2O}（2），来自三铜（II）次级建筑单元（SBU），[Cu3(Hmesox)3]（3-）（H4mesox = 马来酸，2-二羟基丙二酸）。化合物 1 是通过 SBU 与醋酸锰（II）在钾阳离子和 18-冠-6 醚存在下反应得到的，而化合物 2 是通过 SBU 与醋酸锰（II）在 Ph4PCl 存在下反应得到的。化合物 1 和 2 中的[MnCu3(Hmesox)3]（-）和[MnCu3(Hmesox)3Cl]（2-）部分分别产生手性 3 连接的三维（3D）阴离子（10,3）-a（srs，SrSi（2））网。在立方和中心对称结构（Pa3）中，1 中的两个反转对称相关的阴离子网相互渗透形成外消旋结构。2 中的 Ph4P+阳离子通过 6 倍苯基拥抱组织在超分子（10,3）-a 网上。在 2 中，阳离子和阴离子网均为手性且纯手性，具有相反的手性，在非中心对称 Sohncke 空间群 P 2（1）2（1）2（1）中形成互穿超分子和共价（10,3）-a 网。这两种化合物在 1 和 2 中分别在低于 2.5 和 15.2 K 时显示出长程磁有序的铁磁相互作用。2 的脱水相在 21.8 K 时表现出 T（c）。饱和磁化强度 M（S）表明，1 和 2 中三铜（II）单元分别具有两个不同的基态，S =（1）/（2）和（3）/（2）。通过在[Cu3(Hmesox)3]（3-）和[Cu3(Hmesox)3Cl]（4-）片段中分别进行密度泛函理论（DFT）研究，解释了 1 和 2 中三铜（II）单元的不同自旋态。进一步的 DFT 研究允许分析导致两种化合物中三核单元不同自旋基态的结构参数。
