Programa de Pós-Graduação em Química, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
Departamento de Química Inorgânica, Instituto de Química, Universidade Federal Fluminense, Outeiro de S. João Batista s/n., Centro, Niterói, RJ, 24210-130, Brazil.
J Mol Model. 2023 Jun 7;29(7):203. doi: 10.1007/s00894-023-05604-6.
Xanthates are organic compounds that present great interest for coordination chemistry, because they can bond in different ways to the metal ion. Thus, these compounds have several applications, being best known for their environmental application. In fact, xanthates are recognized for their application as heavy metal collector agents in aqueous environments. In view of this application, this study is aimed at showing the thermochemical and electronic parameters obtained for the reactions of substitution water molecules in the aqua zinc complexes, by xanthate ligands (n-propyl, n-butyl, and n-pentyl xanthates). In addition to their environmental application, xanthates have shown biological properties, such as anti-bacterial and anti-cancer. In recent years, xanthates have also been used in the technological area, where it participates as a precursor of sulfides for the manufacture of thin films. Our results showed complexes with distorted octahedral geometries and with negative values of enthalpy and Gibbs free energy, indicating exothermic and spontaneous processes. For all the complexes, it was observed that Zn complexes have both an ionic and covalent character. However, the monosubstituted complexes showed a predominance of the ionic character. In addition, high donor-acceptor interaction energies were obtained, indicating a good superposition between the s and p orbitals involved in the Zn-S bond.
This work consists in theoretical studies of Zn complexes with alkyl xanthate ligands, with different structures, where optimization and normal modes calculations were performed at different DFT levels: M06L, M06-2X, wB97XD, and B3LYP/6-311++G**+LANL2TZ, with Gaussian09 program. The process of substitution of two aqua by two xanthate ligands was analyzed in stages, forming cationic and neutral complexes, in the first and second stages, respectively. In addition, electronic energy decomposition (EDA) and natural bond orbital (NBO) analysis were performed at level M06L/6-311++G**+LANL2TZ with Gamess program.
黄原酸盐是一类具有配位化学研究价值的有机化合物，因为它们可以通过不同的方式与金属离子键合。因此，这些化合物有多种应用，其中最著名的是其在环境方面的应用。事实上，黄原酸盐因其在水相环境中作为重金属捕集剂的应用而被广泛认可。鉴于这种应用，本研究旨在展示通过黄原酸配体（正丙基、正丁基和正戊基黄原酸）取代水合锌配合物中的水分子的反应的热化学和电子参数。除了在环境方面的应用外，黄原酸盐还具有抗菌和抗癌等生物特性。近年来，黄原酸盐也在技术领域得到了应用，它作为用于制造薄膜的硫化物的前体。我们的结果表明，配合物具有扭曲的八面体几何形状，焓和吉布斯自由能为负值，表明是放热和自发的过程。对于所有的配合物，都观察到 Zn 配合物具有离子和共价两种特性。然而，单核取代配合物表现出离子特性的优势。此外，还得到了高的给体-受体相互作用能，表明涉及 Zn-S 键的 s 和 p 轨道之间具有良好的叠加。
这项工作包括具有不同结构的烷基黄原酸锌配合物的理论研究，在不同的密度泛函理论（DFT）水平下进行了优化和正则模式计算：M06L、M06-2X、wB97XD 和 B3LYP/6-311++G**+LANL2TZ，使用 Gaussian09 程序。分析了两个水合配体被两个黄原酸配体取代的过程，形成了阳离子和中性配合物，分别处于第一和第二阶段。此外，还在 M06L/6-311++G**+LANL2TZ 水平下使用 Gamess 程序进行了电子能分解（EDA）和自然键轨道（NBO）分析。
