Theoretical and experimental investigation on the electronic properties of the shuttlecock shaped and the double-decker structured metal phthalocyanines, MPc and M(Pc)2 (M = Sn and Pb)
Theoretical and experimental investigation on the electronic properties of the shuttlecock shaped and the double-decker structured metal phthalocyanines, MPc and M(Pc)2 (M = Sn and Pb)
复制标题
羽毛球状和双层结构金属酞菁MPc和M(Pc)2（M = Sn和Pb）电子性能的理论和实验研究
DOI：
10.1039/c2dt30187c
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发表时间：
2012
影响因子：
4
通讯作者：
Hitoshi Fujimoto
中科院分区：
文献类型：
--
作者：
Michinori Sumimoto;Teruyuki Honda;Yukio Kawashima;Kenji Hori;Hitoshi Fujimoto
在密度泛函理论(DFT)的框架下，用B3LYP方法研究了锡和铅的化合物SnPc、PbPc、SnPc和Pc)2的分子几何、电子结构和激发能.分别在C4v、C4v、D4D和D4D分子对称性下优化了SnPc、PbPc、SnPc和Pc)2的几何构型。用含时密度泛函方法(TD-DFT)计算了这些分子的激发能。对未知Pc(Pc)2以外的三种化合物的激发态的计算结果与电子吸收光谱的实验结果吻合较好。SnPc和PbPc的非平面C4v分子结构通过中心金属原子的S型原子轨道以反键的方式混合到Pc环的−体系中，特别是对HOMOπ1的轨道能量有影响，而HOMO和LUMO对平面结构的偏离影响很小，因为它们对中心金属的原子轨道没有贡献.这种轨道混合推高了HOMO−1的轨道能量，降低了SNPC和PbPC的金属-配体电荷转移带的能量。计算结果也很好地再现了锡(Pc)2的激发轮廓，这与SnPc的激发轮廓有很大的不同。两个Pc基团的π类轨道之间的强相互作用改变了电子结构，形成了锡(Pc)2的特征激发谱。此外，与包括SnPc在内的常用MPC相比，其电离势降低了约0.8 eV，这与实验结果一致。
The molecular geometries, electronic structures, and excitation energies of tin and lead phthalocyanine compounds, SnPc, PbPc, Sn(Pc)2, and Pb(Pc)2, were investigated using the B3LYP method within a framework of density functional theory (DFT). The geometries of SnPc, PbPc, Sn(Pc)2, and Pb(Pc)2 were optimized under C4v, C4v, D4d, and D4d molecular symmetries, respectively. The excitation energies of these molecules were computed by the time-dependent DFT (TD-DFT) method. The calculated results for the excited states of three compounds other than the unknown Pb(Pc)2 corresponded well with the experimental results of electronic absorption spectroscopy. The non-planar C4v molecular structure of SnPc and PbPc influences especially on the orbital energy of the HOMO−1 through mixing of the s-type atomic orbital of the central metal atom to the π system of the Pc ring in an anti-bonding way; however, the HOMO and the LUMO have little effect of the deviation from the planar structure because they have no contribution from the atomic orbital of the central metal. This orbital mixing pushes up the orbital energy of the HOMO−1, and reduces the energy of the metal-to-ligand charge transfer band of SnPc and PbPc. The calculated results also reproduced well the excitation profile of Sn(Pc)2, which was quite different from that of SnPc. The strong interactions between the π-type orbitals of two Pc moieties altered the electronic structure resulting in the characteristic excitation profile of Sn(Pc)2. In addition, this caused a reduction of about 0.8 eV in the ionization potential as compared to usual MPcs including SnPc, which was consistent with the experimental results.