B-C binary monolayers and fullerenes (borafullerenes) have received considerable attention in recent years. Inspired by the newly reported B₄C₃ semiconducting boron carbide monolayer isovalent to graphene (Tian et al., Nanoscale, 2019, 11, 11099), we predict herein at density functional theory level a new class of borafullerenes (1–8) following the isolated B₄C₃ hexagonal pyramid rule. The spherically aromatic borafullerenes C_5h B₂₀C₃₅ (1), C₅ B₂₀C₄₅ (2), C_5h B₂₀C₅₅ (3), and C₅ B₂₀C₆₅ (4) isovalent to C₅₀, C₆₀, C₇₀, and C₈₀, respectively, possess five isolated B₄C₃ hexagonal pyramids evenly distributed on the waist around the C₅ molecular axis, while S₁₀ B₄₀C₅₀ (5), C₅ B₄₀C₆₀ (6), S₁₀ B₄₀C₇₀ (7), and C₅ B₄₀C₈₀ (8) encompass ten isolated B₄C₃ pyramids symmetrically distributed on the cage surface. Detailed orbital and bonding analyses indicate that these borafullerenes follow similar σ and π-bonding patterns with their fullerene analogues, with three delocalized 7c-2e π bonds forming a local π-aromatic system over each isolated B₄C₃ hexagonal pyramid. The calculated formation energies of the (B₄C₃)_nC_60-6n (n = 1–5) series isovalent to C₆₀ appear to increase almost linearly with the number of isolated B₄C₃ pyramids in the system. The IR, Raman, and UV-vis spectra of the prototypical B₂₀C₄₅ (2) are theoretically simulated to facilitate its future spectral characterization.

中文翻译：

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遵循孤立的B4C3六角金字塔规则的新型BC二元富勒烯。

近年来，BC二元单分子层和富勒烯（borafullerenes）受到了相当大的关注。通过在新报告的乙启发₄ Ç ₃半导体碳化硼单层等价于石墨烯（Tian等人，。纳米，2019，11，11099），我们在此预测在密度泛函理论级一类新的borafullerenes的（1 - 8）以下孤立的B ₄ C ₃六棱锥规则。球形芳族硼富勒烯C _{5 h} B ₂₀ C ₃₅（1），C ₅ B ₂₀ C ₄₅（2），分别与C ₅₀，C ₆₀，C ₇₀和C ₈₀等价的C _{5 h} B ₂₀ C ₅₅（3）和C ₅ B ₂₀ C ₆₅（4）具有五个孤立的六角形B ₄ C ₃金字塔围绕C ₅分子轴均匀分布在腰上，而S ₁₀ B ₄₀ C ₅₀（5），C ₅B ₄₀ C ₆₀（6），S ₁₀ B ₄₀ C ₇₀（7）和C ₅ B ₄₀ C ₈₀（8）包含十个在笼子表面对称分布的孤立的B ₄ C ₃金字塔。详细的轨道和键合分析表明，这些硼富勒烯及其富勒烯类似物遵循相似的σ和π键模式，三个离域7c-2eπ键在每个孤立的B ₄ C _3上形成局部π-芳族系统六角形金字塔。 与系统中C ₆₀等价的（B ₄ C ₃）_n C _{60-6 n}（n = 1–5）系列的计算形成能似乎随系统中孤立B ₄ C ₃金字塔的数量线性增加。从理论上模拟了原型B ₂₀ C ₄₅（2）的IR，拉曼和UV-vis光谱，以利于其将来的光谱表征。