Department of Physics, The University of Texas at El Paso, El Paso, Texas 79958, USA.
J Chem Phys. 2012 Aug 28;137(8):084317. doi: 10.1063/1.4739272.
Porphyrin and fullerene donor-acceptor complexes have been extensively studied for their photo-induced charge transfer characteristics. We present the electronic structure of ground states and a few charge transfer excited states of four cofacial porphyrin-fullerene molecular constructs studied using density functional theory at the all-electron level using large polarized basis sets. The donors are base and Zn-tetraphenyl porphyrins and the acceptor molecules are C(60) and C(70). The complexes reported here are non-bonded with a face-to-face distance between the porphyrin and the fullerene of 2.7 to 3.0 Å. The energies of the low lying excited states including charge transfer states calculated using our recent excited state method are in good agreement with available experimental values. We find that replacing C(60) by C(70) in a given dyad may increase the lowest charge transfer excitation energy by about 0.27 eV. Variation of donor in these complexes has marginal effect on the lowest charge transfer excitation energy. The interfacial dipole moments and lowest charge transfer states are studied as a function of face-to-face distance.
卟啉和富勒烯给体-受体配合物因其光诱导电荷转移特性而得到了广泛的研究。我们使用全电子水平的大极化基组，通过密度泛函理论研究了四个共面卟啉-富勒烯分子结构的基态和几个电荷转移激发态的电子结构。供体为碱基和 Zn-四苯基卟啉，受体分子为 C(60)和 C(70)。这里报道的配合物是非键合的，卟啉和富勒烯之间的面对面距离为 2.7 到 3.0 Å。使用我们最近的激发态方法计算得到的低能激发态能量，包括电荷转移态，与可用的实验值吻合良好。我们发现，在给定的偶联物中用 C(70)取代 C(60)可能会使最低的电荷转移激发能增加约 0.27 eV。这些配合物中供体的变化对最低电荷转移激发能的影响很小。界面偶极矩和最低的电荷转移态作为面对面距离的函数进行了研究。
