Castillo Ulises Jiménez, López Héctor, Guadarrama Patricia, Fomine Serguei
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México, Apartado Postal 70-360, CU, Coyoacán, Mexico, DF, 04510, Mexico.
J Mol Model. 2015 May;21(5):129. doi: 10.1007/s00894-015-2676-3. Epub 2015 Apr 28.
Complexes of 21,23-dioxaporphyrin with neutral Zn, Cd, Hg, Cu, Ag, and Au atoms as well as some one-dimensional arrays of those complexes containing up to ten repeat units were modeled at the PBE/def2-TZVPP level of theory with D3 empirical dispersion correction. The binding energy between the metal atom and the macrocycle was found to vary from 90 kcal/mol for Cu to -14 kcal/mol for Hg. Strong charge transfer from the metal to the macrocycle accompanied complex formation. The complexes were able to form dimers and nanoarrays that were held together mostly by dispersion forces. Different types of dimers were studied: face-to-face (F) and two types of parallel-displaced ones. F dimers were calculated to be the lowest-energy structures for Cu and Ag systems. Nanoarray formation was studied for these complexes. The band gaps (Eg) of the nanoarrays were found to be smaller than 1 eV, and decreased slightly as the number of repeat units in the nanoaggregates increased. The ionization potentials and electron affinities were greatly affected by the number of repeat units due to the delocalization of polarons over the entire nanoarray. The polaron delocalization and the related reorganization energies depended to a considerable extent on the metal present in the complex. For the studied nanoarrays, the reorganization energies for hole and electron transport decreased linearly with 1/n, where n is the number of repeat units in the nanoaggregate; for an infinitely long chain, the reorganization energy was zero for electron transport and 0.03-0.04 eV for hole transport.
在PBE/def2-TZVPP理论水平下，采用D3经验色散校正，对21,23 - 二氧杂卟啉与中性锌、镉、汞、铜、银和金原子形成的配合物以及包含多达十个重复单元的这些配合物的一些一维阵列进行了建模。发现金属原子与大环之间的结合能从铜的90千卡/摩尔到汞的 - 14千卡/摩尔不等。配合物形成过程中伴随着从金属到大环的强烈电荷转移。这些配合物能够形成主要由色散力维系在一起的二聚体和纳米阵列。研究了不同类型的二聚体：面对面（F）型和两种平行错位型。计算得出F二聚体是铜和银体系中能量最低的结构。对这些配合物的纳米阵列形成进行了研究。发现纳米阵列的带隙（Eg）小于1电子伏特，并且随着纳米聚集体中重复单元数量的增加而略有降低。由于极化子在整个纳米阵列上的离域，电离势和电子亲和势受到重复单元数量的极大影响。极化子离域和相关的重组能在很大程度上取决于配合物中存在的金属。对于所研究的纳米阵列，空穴和电子传输的重组能随1/n线性降低，其中n是纳米聚集体中的重复单元数量；对于无限长链，电子传输的重组能为零，空穴传输的重组能为0.03 - 0.04电子伏特。
