Stati Dumitru, van Leusen Jan, Kravtsov Victor Ch, Chumakov Yurii, Kögerler Paul, Baca Svetlana G
Institute of Applied Physics, Moldova State University Academiei 5 2028 Chisinau R. Moldova
Institute of Inorganic Chemistry, RWTH Aachen University Landoltweg 1 52074 Aachen Germany.
RSC Adv. 2025 Jun 2;15(23):18209-18223. doi: 10.1039/d5ra02513c. eCollection 2025 May 29.
Under similar synthetic conditions, by the interaction of Co(ib) (Hib = isobutyric acid) and M(NO)·HO with a tridentate organic ligand -butyldiethanolamine (Hbdea) in acetonitrile, a series of heterometallic {Co(iii)-M(iii)} complexes with different cores {CoM}, {CoM}, {CoM}, {CoM}, and {CoM} have been isolated. The series includes tetranuclear [CoM(OH)(ib)(bdea)(NO)]·2MeCN (M(III) = Y (1), Ho (2), Er (3)), pentanuclear [CoM(OH)(ib)(bdea)(NO)]·MeCN (M(iii) = Pr ( = 1.5, 4), Nd ( = 1.5, 5), Sm ( = 2, 6)), hexanuclear [CoEu(OH)(ib)(bdea)(NO)(HO)]·(7) and CoYb(OH)(ib)(bdea)(HO)·3MeCN·1.5HO (8), and octanuclear [CoM(OH)(ib)(bdea)(NO)] (M(iii) = Gd (9), Tb (10)) clusters. The structures of all clusters have been determined by single crystal X-ray diffraction and reveal novel structural features in the series. The tetranuclear (1-3), pentanuclear (4-6), and octanuclear (9-10) clusters are isostructural and isomorphic in their own group. Clusters 1-3 have a rhombic strictly planar tetranuclear central {CoM(μ-OH)} core resembling a common "butterfly" motif. Clusters 4-6 possess a robust and unusual topology, previously unseen in Co/Ln chemistry, of three {CoM(μ-OH)}, {CoM(μ-O)}, and {CoM(μ-O)} noncoplanar triangles sharing a common M(iii) site. The arrangement of metal atoms in 9 and 10 is reminiscent of a smaller square defined by four M(iii) sites inscribed in a larger square formed by four Co(iii) sites, and can also be viewed as a core composed of four {CoM(μ-OH)} nearly coplanar triangles sharing two M(iii) vertices with two neighbouring triangles. Cluster 7 can be viewed as a hexanuclear central core of two parallel {CoM(μ-OH)} triangles, while cluster 8 is composed of three {CoM(μ-OH)} triangles sharing the common M(iii) vertices. DC magnetic data show non-interacting or very weakly interacting Ln(iii) centers and low spin Co(iii) centers. AC magnetic data show relevant out-of-phase signals only for 3 below 4 K and by application of static magnetic bias fields. First principles calculations have been performed to estimate the magnetic anisotropy energies of the prepared compounds and to calculate the exchange coupling between the lanthanides in them.
在相似的合成条件下，通过在乙腈中使二异丁酸钴（Co(ib)，Hib = 异丁酸）与M(NO)₃·H₂O和三齿有机配体——丁基二乙醇胺（Hbdea）相互作用，分离得到了一系列具有不同核结构{CoM}、{CoM}、{CoM}、{CoM}和{CoM}的异金属{Co(iii)-M(iii)}配合物。该系列包括四核[CoM(OH)(ib)(bdea)(NO)]·2MeCN（M(III) = Y (1)、Ho (2)、Er (3)）、五核[CoM(OH)(ib)(bdea)(NO)]·MeCN（M(iii) = Pr ( = 1.5, 4)、Nd ( = 1.5, 5)、Sm ( = 2, 6)）、六核[CoEu(OH)(ib)(bdea)(NO)(H₂O)]·(7)和CoYb(OH)(ib)(bdea)(H₂O)·3MeCN·1.5H₂O (8)以及八核[CoM(OH)(ib)(bdea)(NO)]（M(iii) = Gd (9)、Tb (10)）簇合物。所有簇合物的结构均通过单晶X射线衍射确定，并揭示了该系列中新颖的结构特征。四核（1 - 3）、五核（4 - 6）和八核（9 - 10）簇合物在各自的组内是同构的。簇合物1 - 3具有菱形的严格平面四核中心{CoM(μ - OH)}核，类似于常见的“蝴蝶” motif。簇合物4 - 6具有一种在Co/Ln化学中前所未见的强大且不寻常的拓扑结构，即三个{CoM(μ - OH)}、{CoM(μ - O)}和{CoM(μ - O)}非共面三角形共享一个共同的M(iii)位点。9和10中金属原子的排列让人联想到由四个M(iii)位点定义的较小正方形内接于由四个Co(iii)位点形成的较大正方形中，也可视为由四个{CoM(μ - OH)}近乎共面的三角形组成的核心，与两个相邻三角形共享两个M(iii)顶点。簇合物7可视为由两个平行的{CoM(μ - OH)}三角形组成的六核中心核心，而簇合物8由三个共享共同M(iii)顶点的{CoM(μ - OH)}三角形组成。直流磁性数据显示Ln(iii)中心和低自旋Co(iii)中心不相互作用或相互作用非常弱。交流磁性数据仅在4 K以下的3以及施加静态磁偏置场时显示出相关的异相信号。已进行第一性原理计算以估计所制备化合物的磁各向异性能量，并计算其中镧系元素之间的交换耦合。
