The electronic transmission through σ-conjugated molecules can be fully suppressed by destructive quantum interference, which makes them potential candidates for single-molecule insulators. The first molecule with clear suppression of the single-molecule conductance due to σ-interference was recently found in the form of a functionalized bicyclo[2.2.2]octasilane. Here we continue the search for potential single-molecule insulators based on saturated group 14 molecules. Using a high-throughput screening approach, we assess the electron transport properties of the bicyclo[2.2.2]octane class by systematically varying the constituent atoms between carbon, silicon, and germanium, thus exploring the full chemical space of 771 different molecules. The majority of the molecules in the bicyclo[2.2.2]octane class are found to be highly insulating molecules. Though the all-silicon molecule is a clear-cut case of σ-interference, it is not unique within its class and there are many potential molecules that we predict to be more insulating. The finding of this class of quantum interference based single-molecule insulators indicates that a broad range of highly insulating saturated group 14 molecules are likely to exist.

中文翻译：

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双环[2.2.2]辛烷基：一类基于饱和第14组量子干扰的单分子绝缘子。

破坏性的量子干扰可以完全抑制通过σ共轭分子的电子传输，这使其成为单分子绝缘子的潜在候选者。最近发现以功能化的双环[2.2.2]八硅烷的形式，第一个由于σ干扰而具有明显抑制单分子电导的分子。在这里，我们继续基于饱和的第14组分子寻找潜在的单分子绝缘子。使用高通量筛选方法，我们通过系统地改变碳，硅和锗之间的组成原子，从而评估了771个不同分子的完整化学空间，从而评估了双环[2.2.2]辛烷类的电子传输性质。发现双环[2.2.2]辛烷类中的大多数分子是高度绝缘的分子。尽管全硅分子是σ干扰的明显例子，但它在同类产品中并不是唯一的，我们预测有许多潜在的分子具有更高的绝缘性。这类基于量子干扰的单分子绝缘子的发现表明，很可能存在范围广泛的高度绝缘的饱和第14组分子。