Despite the vast array of ηⁿ-carbocyclic C_5–8 complexes reported for actinides, cyclobutadienyl (C₄) remain exceedingly rare, being restricted to six uranium examples. Here, overcoming the inherent challenges of installing highly reducing C₄-ligands onto actinides when using polar starting materials such as halides, we report that reaction of [Th(η⁸-C₈H₈)₂] with [K₂{C₄(SiMe₃)₄}] gives [{Th(η⁴-C₄[SiMe₃]₄)(μ-η⁸-C₈H₈)(μ-η²-C₈H₈)(K[C₆H₅Me]₂)}₂{K(C₆H₅Me)}{K}] (1), a new type of heteroleptic actinocene. Quantum chemical calculations suggest that the thorium ion engages in π- and δ-bonding to the η⁴-cyclobutadienyl and η⁸-cyclooctatetraenyl ligands, respectively. Furthermore, the coordination sphere of this bent thorocene analogue is supplemented by an η²-cyclooctatetraenyl interaction, which calculations suggest is composed of σ- and π-symmetry donations from in-plane in- and out-of-phase CC 2p-orbital combinations to vacant thorium 6d orbitals. The characterisation data are consistent with this being a metal–alkene-type interaction that is integral to the bent structure and stability of this complex.

中文翻译：

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异杀菌放线菌：:( IV）-环丁二烯基-环辛酸酯基-二钾-环辛酸酯基

尽管η浩大的^Ñ -碳环Ç _5-8络合物报道锕系元素，cyclobutadienyl（C ₄）保持极其罕见的，被限制到六个铀例子。在此，克服安装高度减少C的固有的挑战_4个使用极的起始原料如卤化物时-ligands到锕系元素，我们报告的该反应[钍（η ⁸ -C ₈ ħ ₈）₂ ]与[K ₂ {C ₄（森达₃）₄ }]给出[{钍（η ⁴ -C ₄ [森达₃ ] ₄）（μ-η ⁸-C ₈ ħ ₈）（μ-η ² -C ₈ ħ ₈）（K [C ₆ H ^ ₅本人] ₂）} ₂ [KP（C ₆ H ^ ₅ Me）的} {K}]（1），一个新的杂化光化学世的类型。量子化学计算的是，钍离子接合在π-和δ-结合到η建议⁴ -cyclobutadienyl和η ⁸分别-cyclooctatetraenyl配体，。此外，该弯曲thorocene类似物的配位球由η补充²计算表明，β-环辛基异戊烯基相互作用是由平面内同相和异相C C 2p轨道组合到空or 6d轨道的σ和π对称捐赠构成的。表征数据与此一致，这是金属-烯烃类型的相互作用，是该复合物弯曲结构和稳定性不可或缺的。