Carbon-based frameworks composed of sp3 bonding represent a class of extremely lightweight strong materials, but only diamond and a handful of other compounds exist despite numerous predictions. Thus, there remains a large gap between the number of plausible structures predicted and those synthesized. We used a chemical design principle based on boron substitution to predict and synthesize a three-dimensional carbon-boron framework in a host/guest clathrate structure. The clathrate, with composition 2Sr@B6C6, exhibits the cubic bipartite sodalite structure (type VII clathrate) composed of sp3-bonded truncated octahedral C12B12 host cages that trap Sr2+ guest cations. The clathrate not only maintains the robust nature of diamond-like sp3 bonding but also offers potential for a broad range of compounds with tunable properties through substitution of guest atoms within the cages.

中文翻译：

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碳硼包合物是新型的sp3键合骨架材料。

由sp3键组成的碳基骨架代表了一类极其轻便的坚固材料，尽管有许多预测，但仅存在金刚石和少数其他化合物。因此，在预测的合理结构与合成的结构之间仍然存在很大的差距。我们使用基于硼取代的化学设计原理来预测和合成宿主/客体包合物结构中的三维碳-硼骨架。笼形物的成分为2Sr @ B6C6，显示出立方二方方钠石结构（VII型笼形物），该结构由捕获Sr2 +客体阳离子的sp3键合的截短的八面体C12B12主笼组成。