Department of Chemistry, National Taiwan Normal University, Taipei 116, Taiwan, Republic of China.
Chem Asian J. 2013 May;8(5):963-73. doi: 10.1002/asia.201201163. Epub 2013 Feb 18.
The reactions of E powder (E=S, Se) with a mixture of Cr(CO)6 and Mn2(CO)10 in concentrated solutions of KOH/MeOH produced two new mixed Cr-Mn-carbonyl clusters, E2CrMn2(CO)9 (E=S, 1; Se, 2). Clusters 1 and 2 were isostructural with one another and each displayed a trigonal-bipyramidal structure, with the CrMn2 triangle axially capped by two μ3-E atoms. The analogous telluride cluster, Te2CrMn2(CO)9 (3), was obtained from the ring-closure of Te2Mn2 ring complex Te2Mn2Cr2(CO)18 (4). Upon bubbling with CO, clusters 2 and 3 were readily converted into square-pyramidal clusters, E2CrMn2(CO)10 (E=Se, 5; Te, 6), accompanied with the cleavage of one Cr-Mn bond. According to SQUID analysis, cluster 6 was paramagnetic, with S=1 at room temperature; however, the Se analogue (5) was spectroscopically proposed to be diamagnetic, as verified by TD-DFT calculations. Cluster 6 could be further carbonylated, with cleavage of the Mn-Mn bond to produce a new arachno-cluster, Te2CrMn2(CO)11 (7). The formation and structural isomers, as well as electrochemistry and UV/Vis absorption, of these clusters were also elucidated by DFT calculations.
E 粉（E=S、Se）与 Cr(CO)6 和 Mn2(CO)10 的混合物在浓 KOH/MeOH 溶液中的反应生成了两个新的混合 Cr-Mn 羰基簇，E2CrMn2(CO)9（E=S，1；Se，2）。簇 1 和 2 彼此结构相同，每个簇都呈现出三角双锥结构，CrMn2 三角形轴向被两个 μ3-E 原子封端。类似的碲化物簇，Te2CrMn2(CO)9（3），是由 Te2Mn2 环配合物Te2Mn2Cr2(CO)18（4）的闭环反应得到的。在 CO 的鼓泡作用下，簇 2 和 3 很容易转化为四方锥型的簇，E2CrMn2(CO)10（E=Se，5；Te，6），同时伴随着一个 Cr-Mn 键的断裂。根据 SQUID 分析，簇 6 是顺磁性的，室温下 S=1；然而，其 Se 类似物（5）通过 TD-DFT 计算被证明为抗磁性的，这与光谱学结果一致。簇 6 可以进一步羰基化，同时 Mn-Mn 键断裂，生成一个新的蛛网型簇，Te2CrMn2(CO)11（7）。通过 DFT 计算还阐明了这些簇的形成和结构异构体、电化学和紫外/可见吸收。
