Fizer Maksym, Sidey Vasyl, Milyovich Stepan, Fizer Oksana
Faculty of Chemistry, Uzhhorod National University, Pidhirna Str., 46, 88000, Uzhhorod, Ukraine.
Research Institute for Physics and Chemistry of Solid State, Uzhhorod National University, Pidhirna Str., 46, 88000, Uzhhorod, Ukraine.
J Mol Graph Model. 2021 Jan;102:107800. doi: 10.1016/j.jmgm.2020.107800. Epub 2020 Nov 9.
3,7,8-Trihydroxy-3-methyl-10-oxo-4,10-dihydro-1H,3H-pyrano [4,3-b]chromene-9-carboxylic acid is a structurally well-characterized fulvic acid (FA) capable to act as a polyfunctional bidentate ligand in the complexes with metal ions. Investigations of the formation mechanisms and structure of the above-mentioned FA complexes with bivalent metals [Cd(II), Cu(II), Mg(II), Ni(II), Pb(II) and Zn(II)] are presently an actual and trending topic in the modern chemistry of humic and fulvic acids. Furthermore, the importance of the theoretical DFT investigations of binding of metals with fulvic acids is stipulated by the lack of the relevant experimental structural data for such complexes. The quantum chemical calculations have shown that, of the four possible FA tautomers, the two FA forms are more stable. The wavefunction analysis and computed reactivity descriptors (electrostatic potential, Hirshfeld surface analysis, natural population analysis charges, and condensed Fukui indexes) give the insight on the properties and reactive ability of these two different forms of the FA. The computed thermochemical parameters of the ion-exchange reaction explain the metal binding affinity and selectivity of the FA forms.
3,7,8-三羟基-3-甲基-10-氧代-4,10-二氢-1H,3H-吡喃并[4,3-b]色烯-9-羧酸是一种结构特征明确的富里酸（FA），能够在与金属离子形成的配合物中充当多功能双齿配体。目前，研究上述富里酸与二价金属[Cd(II)、Cu(II)、Mg(II)、Ni(II)、Pb(II)和Zn(II)]形成配合物的形成机制和结构，是现代腐殖酸和富里酸化学领域的一个实际且热门的话题。此外，由于缺乏此类配合物的相关实验结构数据，对金属与富里酸结合进行理论密度泛函理论（DFT）研究显得尤为重要。量子化学计算表明，在四种可能的富里酸互变异构体中，有两种富里酸形式更稳定。波函数分析和计算得到的反应性描述符（静电势、 Hirshfeld表面分析、自然布居分析电荷和凝聚福井指数）揭示了这两种不同形式富里酸的性质和反应能力。计算得到的离子交换反应热化学参数解释了富里酸形式对金属的结合亲和力和选择性。
