Ni6 clusters of the general formula [Ni3Ln(OAc)(OH)}2(X)(OAc)(H2O)2] (n = 1, 2; X = Cl− or N3−, (Ln)3− = hexadentate tritopic ligands) can be isolated by spontaneous self-assembly, from mixtures of Ni(OAc)2, H3Ln, NMe4OH·5H2O and NaX in adequate molar ratios. Thus, four new hexanuclear complexes [Ni3L1(OAc)(OH)}2Cl(OAc)(H2O)2]·7.5H2O (1·7.5H2O), [Ni3L2(OAc)(OH)}2Cl(OAc)(H2O)2]·2H2O·7.5MeOH (2·2H2O·7.5MeOH), [Ni3L1(OAc)(OH)}2(N3)(OAc)(H2O)2]·6H2O (3·6H2O) and [Ni3L2(OAc)(OH)}2(N3)(OAc)(H2O)2]·4H2O (4·4H2O) were obtained and fully characterised. 1·7.5H2O and 2·2H2O·7.5MeOH were isolated in the form of single crystals, the latter losing solvate on drying, to yield 2·2H2O. Recrystallisation of 3·6H2O in MeCN/MeOH also generates single crystals of 3·H2O·2MeOH·2MeCN. Their X-ray characterisation shows that these Ni6 clusters can be considered to be built from two triangular trinuclear [Ni3Ln(OAc)(OH)]+ subunits with different connectors. In addition, these studies demonstrate that the (Ln)3− ligands behave as trinucleating, adopting such a conformation that induces chirality in the isolated compounds. In this way, 3·H2O·2MeOH·2MeCN appears particularly interesting, since it emerges as homochiral after undergoing spontaneous resolution upon crystallisation. The magnetic characterisation of 1·7.5H2O to 3·6H2O reveals that the three compounds present an overall antiferromagnetic coupling. The intricate magnetic behaviour of these clusters, mediated by a total of 14 bridges of different kinds, was analysed and satisfactorily interpreted in light of DFT calculations.
通式为[Ni3Ln(
OAc)(OH)}2(X)(
OAc)(
H2O)2]的 Ni6 簇合物(n = 1、2;X = Cl- 或 N3-,(Ln)3- = 六价三位
配体)可通过自发自组装从 Ni(
OAc)2、H3Ln、NMe4OH-5 和 NaX 以适当摩尔比组成的混合物中分离出来。因此,四种新的六核配合物[Ni3L1(
OAc)(OH)}2Cl(
OAc)( )2]-7.5 (1-7.5 )、[Ni3
L2(
OAc)(OH)}2Cl(
OAc)( )2]-2 -7.5MeOH(2-2 -7.5MeOH)、[Ni3L1(
OAc)(OH)}2(N3)(
OAc)( )2]-6 (3-6 )和[Ni3
L2(
OAc)(OH)}2(N3)(
OAc)( )2]-4 (4-4 )。以单晶形式分离出 1-7.5 和 2-2 -7.5MeOH,后者在干燥时失去溶解度,得到 2-2 。3-6 在 MeCN/MeOH 中重结晶也会生成 3- -2MeO
H-2MeCN 的单晶。它们的 X 射线特征显示,这些 Ni6 团簇可视为由两个具有不同连接点的三角形三核 [Ni3Ln(
OAc)(OH)]+ 亚基构建而成。此外,这些研究还表明,(Ln)3-
配体具有三核行为,其采用的构象诱导了分离化合物的手性。在这种情况下,3- -2MeO
H-2MeCN 显得特别有趣,因为它在结晶时经历了自发解析后出现了同手性。对 1-7.5 和 3-6 进行的磁性分析表明,这三种化合物呈现出整体反
铁磁耦合。根据 DFT 计算,分析并圆满解释了这些簇合物由总共 14 个不同类型的桥所介导的错综复杂的磁性行为。