Ribeiro Igor Hernandes Santos, Reis Davi Texeira, Pereira Douglas Henrique
Chemistry Collegiate, Federal University of Tocantins, Campus Gurupi, Badejós, P.O. Box 66, Gurupi, 77402-970, Brazil.
J Mol Model. 2019 Aug 23;25(9):267. doi: 10.1007/s00894-019-4151-z.
The density functional theory was used to understand the adsorption process of Cd(II), Cr(III), Cu(II), Hg(II), Pb(II), and Zn(II) ions with the methacrylate monomer derived of vanillin (VMA). Different analyses were carried out: Conformational analysis, molecular electrostatic potential (MEP), adsorption energy, frontier orbitals, hardness, and softness, all of which are necessary to predict the formation of complexes. By means of the molecular electrostatic potential and frontier molecular orbital (FMOs), the best region for adsorption was found, so each metallic ion of the study was placed close to the nitrogen and oxygen atoms of the imine and carboxyl groups of vanillin monomer, respectively. The bond of the metal ions with the nitrogen atom was shown to be stronger than with oxygen atoms, because the charge density of the nitrogen is increased in the formation of the Schiff base with the proximity of the aromatic ring. The monomer showed to be more adsorbent for the Cu(II), Cr(III), and Pb(II) ions because of the high energy values involved. The analysis QTAIM was investigated to understand the character of the interaction between vanillin monomer and metal species, which were shown in almost all cases as covalent partial. Thus, the monomer derived from vanillin has good stability in water and is therefore considered a good material for the remediation of effluents and poisonings.
采用密度泛函理论来理解镉（II）、铬（III）、铜（II）、汞（II）、铅（II）和锌（II）离子与香草醛衍生的甲基丙烯酸酯单体（VMA）的吸附过程。进行了不同的分析：构象分析、分子静电势（MEP）、吸附能、前线轨道、硬度和软度，所有这些对于预测配合物的形成都是必要的。借助分子静电势和前线分子轨道（FMOs），找到了最佳吸附区域，因此研究中的每个金属离子分别靠近香草醛单体亚胺和羧基的氮原子和氧原子放置。结果表明，金属离子与氮原子的键比与氧原子的键更强，因为在形成席夫碱时，随着芳香环的靠近，氮的电荷密度增加。由于涉及的能量值较高，该单体对铜（II）、铬（III）和铅（II）离子表现出更强的吸附性。研究了QTAIM分析以了解香草醛单体与金属物种之间相互作用的性质，几乎在所有情况下都显示为部分共价。因此，香草醛衍生的单体在水中具有良好的稳定性，因此被认为是一种用于废水处理和解毒的良好材料。
