Although there are few reduced dinitrogen complexes of scandium, this metal has revealed a new structural type in reductive dinitrogen chemistry by reduction of bis(pentamethylcyclopentadienyl) scandium halides under N₂. Reduction of (Cp* = C₅Me₅) with potassium graphite (KC₈) under dinitrogen generates the dark blue paramagnetic complex , 1. This end-on bridging (NN)²⁻ complex is a diradical with a magnetic moment of 2.8µ_B. Upon further reduction of 1 with KC₈, the orange diamagnetic trimetallic complex , 2, is obtained. This complex has an unprecedented structure in which two side-on bridging (NN)²⁻ ligands are bound to the central (Cp*Sc)²⁺ moiety. Complex 2 can also be obtained directly from reduction of or a mixture of and with KC₈. The reaction of with KC₈ in the presence of 18-crown-6 or 2.2.2-cryptand affords 2 along with small amounts of , 3, which is green at room temperature and purple at low temperature and displays a mixture of side-on and end-on bridging isomers in the crystal structure collected at −180 °C. Density functional theory (DFT) calculations are consistent with a triplet ground state for the end-on complex 1 and singlet ground states for the side-on complexes 2 and 3.

中文翻译：

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与钪的二氮还原化学提供了一种复合物，其两个侧面 (NN)2− 配体与一种金属结合： (C5Me5)Sc[(μ-η2:η2-N2)Sc(C5Me5)2]2


尽管钪的还原二氮配合物很少，但该金属通过在N ₂下还原双（五甲基环戊二烯基）钪卤化物，揭示了还原二氮化学中的新结构类型。减少 (Cp* = C ₅ Me ₅ ) 与钾石墨 (KC ₈ ) 在氮气下生成深蓝色顺磁络合物 , 1 .这种端接桥接（N N) ²⁻络合物是磁矩为 2.8 µ _B的双自由基。用 KC ₈进一步还原1后，得到橙色抗磁性三金属络合物 , 2 , 得到。该复合体具有前所未有的结构，其中两个侧面桥接（N N) ²⁻配体与中心 (Cp*Sc) ²⁺部分结合。配合物2也可以直接通过还原得到 或混合物 和 与 KC ₈ 。反应为 与 KC ₈在 18-crown-6 或 2.2.2-cryptand 存在下提供2以及少量 , 3 ，在室温下为绿色，在低温下为紫色，在-180°C收集的晶体结构中显示出侧桥和端桥异构体的混合物。 密度泛函理论 (DFT) 计算与端配合物1的三重态基态和侧配合物2和3的单重态基态一致。