Wu Jingjing, Zhu Jun
State Key Laboratory of Physical Chemistry of Solid Surfaces, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, Fujian, P. R. China.
Chemphyschem. 2015 Dec 21;16(18):3806-13. doi: 10.1002/cphc.201500811. Epub 2015 Nov 11.
The Clar structure of polybenzenoid hydrocarbons (PBHs) have attracted considerable interest of both theoretical and experimental chemists since it was proposed in the 1950s. However, it remains unclear whether the Clar structure could exist in inorganic PBHs, the boron nitride (BN) analogues where the alternate boron and nitrogen atoms are used to replace the carbon atoms of PBHs. Here, we carry out thorough density functional theory (DFT) calculations to probe the possibility of Clar structures in BN analogues of PBHs. A strong correlation (r(2) =0.975) between the ring number (n=3-10) of BN analogues of [n]acenes and energy differences between the most and least stable isomers is identified, suggesting the existence of Clar structures in inorganic PBHs. In addition, the slightly weaker correlations in comparison to that (r(2) =0.989) of the organic PBHs is rationalized by the reduced aromaticity, which is revealed by two aromatic indices: ELFπ and SCI.
自从20世纪50年代提出以来，多苯型烃（PBHs）的克拉尔结构引起了理论化学家和实验化学家的极大兴趣。然而，目前尚不清楚克拉尔结构是否能存在于无机PBHs中，即氮化硼（BN）类似物中，其中交替的硼和氮原子用于取代PBHs中的碳原子。在此，我们进行了全面的密度泛函理论（DFT）计算，以探究PBHs的BN类似物中克拉尔结构的可能性。我们发现，[n]并苯的BN类似物的环数（n = 3 - 10）与最稳定和最不稳定异构体之间的能量差之间存在很强的相关性（r(2) = 0.975），这表明无机PBHs中存在克拉尔结构。此外，与有机PBHs的相关性（r(2) = 0.989）相比，相关性略弱是由芳香性降低导致的，这通过两个芳香性指标：ELFπ和SCI得以揭示。
