Theoretical study on the stability of double-decker type metal phthalocyanines, M(Pc)2 and M(Pc)2+ (M = Ti, Sn and Sc): critical assessment on the performance of density functionals
Theoretical study on the stability of double-decker type metal phthalocyanines, M(Pc)2 and M(Pc)2+ (M = Ti, Sn and Sc): critical assessment on the performance of density functionals
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双层型金属酞菁 M(Pc)2 和 M(Pc)2 (M = Ti、Sn 和 Sc) 稳定性的理论研究：密度泛函性能的关键评估
DOI：
10.1039/c4cp05645k
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
H. Fujimoto
中科院分区：
文献类型：
--
作者：
M. Sumimoto;Y. Kawashima;K. Hori;H. Fujimoto
本文报道了用B3LYP、B3PW91、B3P86、PBE1PBE、BHandHLYP、BPW91、BP86、BP86、M06、M06-2x、M06-HF、M06L、LC-BPW91、LC-ωPBE、CAM-B3LYP、B97D、ωB97、ωB97X和ωB97XD等18种泛函，对双层结构的酞菁化合物，Ti(Pc)2，Ti(Pc)2+，SnPc(Pc)2+，SnPc(Pc)2+，Sc(Pc)2和Sc(Pc)2+的D4D和D2对称结构的优化结构和相对能量进行了理论计算。在D4D结构中，两个酞菁基团以面对面的方式堆积在一起，但在D2结构中，它们被两个σ-键连接。我们发现，M(Pc)_2和M(Pc)_2+的分子对称性取决于由电子离域稳定和π-电子在酞菁基团中的交换排斥之间的平衡。为了选择合适的泛函用于M(Pc)2和M(Pc)2+的计算，我们对已建立的泛函的性能进行了评估，并得出了几个重要的方面。一般来说，杂化GGA和杂化Meta-GGA泛函具有20-27%的HF交换项，将给出与实验预期的双层型酞菁化合物一致的分子结构。纯GGA和纯偏GGA泛函(BPW91、BP86、M06L和B97D)有高估D4D结构稳定性的倾向。另一方面，包括HF交换50%和超过或包括长程修正的泛函(BHandHLYP，M06，M06-2x，M06-HF，LC-BPW91，LC-ωPBE，CAM-B3LYP，ωB97，ωB97X和ωB97XD)往往高估了D2结构的稳定性。需要强调的是，最常用的具有20%HF交换的杂化GGA泛函之一的B3LYP泛函不能恰当地估计Ti(Pc)2的两种分子结构之间的相对稳定性。本文所考虑的系统的计算需要很好地平衡地处理具有伴随交换相关泛函的HF交换。因此，正如人们经常严格指出的那样，泛函的选择是保证计算可靠性的关键。
We report the results of theoretical calculations on the optimized structures and relative energies between the D4d and D2 symmetry structures for double-decker type phthalocyanine compounds, Ti(Pc)2, Ti(Pc)2+, Sn(Pc)2, Sn(Pc)2+, Sc(Pc)2 and Sc(Pc)2+, using eighteen types of functionals: B3LYP, B3PW91, B3P86, PBE1PBE, BHandHLYP, BPW91, BP86, M06, M06-2x, M06-HF, M06L, LC-BPW91, LC-ωPBE, CAM-B3LYP, B97D, ωB97, ωB97X and ωB97XD. Two phthalocyanine moieties are stacked in a face-to-face configuration in the D4d structure, but they are stapled by two σ-bonds in the D2 one. We found that the molecular symmetry of M(Pc)2 and M(Pc)2+ depends on the balance between stabilization due to electron delocalization and exchange repulsion of π-electrons in the phthalocyanine moieties. We assessed the performance of the well-established functionals to select the appropriate functional for calculations on M(Pc)2 and M(Pc)2+, and several important aspects came out. Generally, the hybrid GGA and hybrid meta-GGA functionals with 20–27% of the HF exchange term would give the molecular structures consistent with the experimental expectations for the double-decker type phthalocyanine compounds. Pure GGA and pure meta-GGA functionals (BPW91, BP86, M06L and B97D) have the tendency to overestimate the stability of the D4d structure. On the other hand, functionals including HF exchange for 50% and over or including long-range corrections (BHandHLYP, M06, M06-2x, M06-HF, LC-BPW91, LC-ωPBE, CAM-B3LYP, ωB97, ωB97X and ωB97XD) tend to overestimate the stability of the D2 structure. It should be emphasized that the B3LYP functional, one of the most commonly used hybrid GGA functionals with 20% HF exchange, cannot estimate the relative stability between the two molecular structures of Ti(Pc)2 appropriately. The calculation for the systems considered in this article required well-balanced treatment of the HF exchange with the accompanied exchange–correlation functional. Thus, as has been pointed out rigorously and frequently, the selection of the functional is a crucial point for reliability of the calculations.