含平面多配位碳纳米团簇和低维纳米材料的理论与实验研究

Low-dimensional carbon-based nanomaterials, such as grahpene, carbon nanotube, and fullerene, are constructed on the basis of the planarity of classical sp2 hybrid carbon. Besides the sp2 hybrid bonding, the planar hypercoordinate carbon (phC) bonding is the the most possible bonding pattern for carbon, which can construct the low-dimensional carbon-based nanomaterials. Recent theoretical studies, which carried out under the ideal conditions, suggested that the materials would exhibit some novel properties if they can possess the novel phC substructure.However, the theoretical studies considering the necessary experimental factors, such as substrates and catalysts, etc. and the related experimental synthesis are not reported. In this project, we plan to efficiently combine the theoretical design and the chemical vapor deposition (CVD) synthesis to systematically study nano-scaled clusters and low-dimensional nanomaterials with phC. In the theoretical work, the necessary deposition conditions, such as substrates, the catalysts, reaction temperatures, and the gas sources, etc. will be sufficiently considered and iteratively revised with the progress of subsequent CVD experiments. Our final goal is to prepare and characterize the nanomaterials with phC in the laboratory. Simultaneously, to satisfy the requirement of studying the low-dimensional nanometerials, we will develop the corresponding strategies to stabilize phC and algorithms to search the global minima structures. It is reasonable to believe that the studies in this project will not only promote the conversion of phC chemistry from the subject that mainly performs the theoretical investigations to the new subject that mainly carries out the experimental synthesis and applications, but also lay the fundation for the development of materials with phC as novel low-dimensional carbon-based nanomaterials.

石墨烯、碳纳米管和富勒烯都是以经典的sp2杂化碳原子的平面成键结构为基础构建的，除了sp2杂化，平面多配位碳（phC）成键是构建低维碳基纳米材料的最有可能方式。近期理想条件下的理论研究表明，在材料中引入phC结构将使其展现出很多新奇的性质，但考虑基体支撑和催化剂等实验必备因素影响的理论研究及相关的实验合成尚未报道。本项目拟以理论设计与化学气相沉积（CVD）实验紧密结合的方式对含phC的纳米团簇和低维纳米材料进行深入系统的研究。理论研究中将充分考虑基体支撑、催化剂、反应温度、气源等CVD实验必备因素的影响，后续CVD实验中不断对这些沉积条件进行修正，制备出含phC的纳米材料。同时，我们将发展适用于低维纳米材料的phC稳定化理论及全局极小结构搜索算法。本项目研究将促进与phC相关学科从以理论研究为主向以实验合成与应用为主的转变，也将为含phC结构的新型低维碳基纳米材料的发展奠定坚实的基础。

石墨烯、碳纳米管和富勒烯都是以经典的sp2 杂化碳原子的平面成键结构为基础构建的，除了sp2 杂化，平面多配位碳（phC）成键是构建低维碳基纳米材料的最有可能方式。但前期的研究中报道的phC结构大多存在稳定性不好的问题而很难被实验制备出来。针对此问题，本项目以高精度量子化学为基础，设计了一系列有利于实验合成的热力学和/或动力学稳定的平面多配位碳小分子，含平面多配位碳纳米团簇和低维纳米材料。具体包括动力学稳定的平面六配位碳分子CN3Mg3(+)，热力学和动力学稳定平面五配位碳分子CBe5Hnn-4 (n = 2–5)，符合超碱金属判据的含有平面五配位碳的分子CBe5X5+ (X = F, Cl, Br, Na, K)，含有平面六配位硼和平面七配位后过渡金属的星状的Be-H化合物，以C2(BeH)4单元设计的链状、片状和管状纳米分子、以含有1,3-金属-碳键的分子通过面对面缩聚的方式设计的含有平面四配位碳的金属有机寡聚纳米分子，以具有在局部离域π电子的星苯多聚体为基础首次成功设计的三维可扩展连续夹心结构，以CBe5H4平面五配位碳单元为基础通过五边形融合设计的首个含有完美平面五配位碳的纳米分子等。以这些研究中的发现为基础，我们还设计了具有前所未见的σ-d相互作用特征的类二茂铁三明治夹心结构M[(BeH)n]2 (M = 第3–11族过渡金属，n = 4–7)，具有与过渡金属五重键相媲美的超短Be-Be间距的分子、具有与SN2反应过渡态结构类似的含有三角双锥五配位碳的分子CA3X2- (A = Al, Ga, X = Si, Ge, Sn, Pb)。本项目研究为实验研究者提供了若干有可能实现含平面多配位碳或相关非经典成键结构的小分子、纳米团簇和低维纳米材料，为平面多配位碳化学向实验合成与应用方向的迈进提供了较有用的线索。本项目的研究成果经整理在Angew. Chem., J. Mater. Chem. C, Phys. Chem. Chem. Phys., J. Chem. Phys.等SCI核心收录期刊发表学术论文17篇，发表其它论文4篇，以申请人为第一完成人获得山西省科学技术奖自然科学二等奖1项，支撑申请人和一名项目组主要成员2人次晋升教授职称，支撑申请人入选山西省高等学校人才计划2项，培养研究生9人次，其中毕业博士生1人，硕士生4人。