Why Do B-P and Al-P Polymers Differ? Structures, Stability, and Electronic Properties of Chain and Ring [H2 PEH2 ]n Oligomers (E=B, Al; n=1-15).
Why Do B-P and Al-P Polymers Differ? Structures, Stability, and Electronic Properties of Chain and Ring [H2 PEH2 ]n Oligomers (E=B, Al; n=1-15).
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DOI：
10.1002/chem.201803008
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
A. Pomogaeva;M. Scheer;A. Timoshkin
中科院分区：
文献类型：
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作者：
A. Pomogaeva;M. Scheer;A. Timoshkin
在B3LYP/Def2-TZVP理论水平上对链状和环状[H2PEH2]n齐聚物(E=B，Al；n=2-15)进行了计算研究。含有n>；7的链状Al-P齐聚物有很强的环化倾向，而类似的长B-P齐聚物可以作为链状结构存在。对于n增加的环状和链状齐聚物，随后的齐聚热非常接近彼此。然而，这些低聚物具有非常不同的电子性质，链[H2 PBH2]15的带隙小于0.2 eV，环异构体[H2 PEH2]15的带隙大于5 eV。环状齐聚物中的分子轨道是高度离域的，而链异构体中的HOMO和LUMO则定位在齐聚物链的不同末端。
Chain and ring [H2 PEH2 ]n oligomers (E=B, Al; n=2-15) have been computationally studied at the B3LYP/def2-TZVP level of theory. A strong tendency to cyclization was found for the chain Al-P oligomers with n>7, whereas analogous long B-P oligomers can exist as chain structures. Subsequent oligomerization enthalpies approach each other very closely for the ring and chain oligomers with an increase of n. However, these oligomers have very different electronic properties with band gaps below 0.2 eV for the chain [H2 PBH2 ]15 and more than 5 eV for the ring isomer [H2 PEH2 ]15 . The molecular orbitals in the ring oligomers are highly delocalized, whereas for the chain isomers, the HOMO and LUMO are localized at the different ends of the oligomeric chain.