The Studies on Structure and Stability of CaBn Clusters
The Studies on Structure and Stability of CaBn Clusters
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DOI：
10.3390/molecules24061011
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发表时间：
2019-03
期刊：
影响因子：
4.6
通讯作者：
P. Han;Fengli Chai;Bolin Qiao;Chunhui Liu
中科院分区：
文献类型：
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作者：
P. Han;Fengli Chai;Bolin Qiao;Chunhui Liu
钙-硼体系具有优良的硬度、强度和化学稳定性，我们研究了一系列的CaB簇合物，研究了它们的结构和相对稳定性。结果表明，CaBN团簇最稳定的结构不是平面的。B原子倾向于聚集在一起形成平面环以稳定结构，而Ca原子则配位到构型的外围。计算了CaBN团簇的平均结合能(EB)、碎裂能(EF)、二阶能差(Δ2E)、绝热剥离能(ADE)和绝热电子亲和势(AEA)，以考察其相对稳定性和移去或获得电子的能力。结果表明，随着n的增加，EF和Δ_2e值有明显的奇偶变化，说明CaB_4、CaB_6和CaB_8组比较稳定。N为偶数的团簇的ADE值大于奇数为n的团簇的ADE值，表明n为偶数的团簇难以去除一个电子。CaB3和CaB7的AEA值较大，说明CaB3和CaB7更容易获得电子。这些结果为理解碱土金属硼化物的形成机理和稳定性提供了有益的参考，也为合成CaN团簇提供了指导。
Calcium-boron systems have excellent properties of hardness, strength, and chemical stability, and we studied a series of CaBn clusters to investigate their structures and relative stability. The results showed the most stable structures of CaBn clusters are not planar. The B atoms tend to get together and form the planar ring to stabilize the structure, and the Ca atoms are coordinated to the periphery of the formations. The average binding energy (Eb), fragmentation energy (EF), second-order energy difference (Δ2E), adiabatic detachment energy (ADE), and adiabatic electron affinity (AEA) of the CaBn clusters were calculated to investigate the relative stability and the ability of removing or obtaining an electron. As shown by the results, EF and Δ2E values had obvious odd-even alteration as n increased, which indicated that the formations CaB4, CaB6, and CaB8 were more stable. The ADE values for CaBn clusters with even values of n were higher than those with odd values of n, which indicated CaBn clusters with even values of n had difficultly removing an electron. The AEA values of CaB3 and CaB7 were larger than the others, which meant CaB3 and CaB7 easily obtained an electron. These results provide a useful reference for understanding the formation mechanism and stability of the alkaline earth metal boride as well as guidance for synthesizing the CaBn clusters.