Diplumbenes, R₂PbPbR₂, are more pyramidalized and trans-bent than the other group 14 analogues and feature long Pb–Pb bonds. A strategy for making these molecules locally planar at Pb, with shorter Pb–Pb separations, starts out from a realization that the Pb–Pb double bond in a hypothetical (LB)PbPb(LB) (LB = Lewis base) is made almost entirely up by 6p orbitals on the Pb atom and has lone pairs on Pb with large 6s character. Coordination of these lone pairs with Lewis acids (LA) should give an ethylene-like structure—effectively a push–pull complex, (LA)(LB)Pb═Pb(LB)(LA). However, the relativistically contracted 6s lone pair on Pb resists effective orbital interaction. To overcome this problem, we evoked in calculations electrostatic interactions between the Pb and Lewis acid ligands, by making the Pb atoms negatively charged and choosing a Lewis acid that carries positive charge. The challenge is to find realistic ligands to engineer these electron shifts. Calculations gave local minima for a diplumbene (LA)(LB)Pb═Pb(LB)(LA), with a base-stabilized borylene as the LB, and LiMe as the LA. These are predicted to be planar and have shorter Pb═Pb double bonds. For the constituent plumbylene (PbR₂) fragments of these candidates, one calculates a triplet ground state.

中文翻译：

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稳定平面双立苯的供体-受体策略

Diplumbenes，R ₂ PbPbR ₂，更呈锥体状和反式-比其他14组类似物弯曲，并且具有长的Pb–Pb键。一种使这些分子在Pb处局部平面且Pb–Pb间隔更短的策略是从认识到，假设（LB）PbPb（LB）（LB = Lewis碱）中的Pb–Pb双键几乎全部制成在Pb原子上沿6p轨道向上运动，在Pb上具有大6s字符的孤对。这些孤对与路易斯酸（LA）的配位应产生类似于乙烯的结构-有效地为推挽复合物（LA）（LB）Pb═Pb（LB）（LA）。但是，Pb上相对论上收缩的6s孤对抵抗有效的轨道相互作用。为了克服这个问题，我们在计算中通过使Pb原子带负电荷并选择带有正电荷的Lewis酸来计算Pb和Lewis酸配体之间的静电相互作用。面临的挑战是找到可实现这些电子位移的现实配体。计算得出了以二茂苯（LA）（LB）Pb═Pb（LB）（LA）为局部最小值的情况，其中碱稳定的亚芳基为LB，LiMe为LA。预计它们是平面的，并具有较短的Pb═Pb双键。对于组成plum（PbR₂）这些候选的片段，一个计算一个三重态的基态。