Barrena-Espés Daniel, Martín Pendás Ángel, Riedel Sebastian, Pérez-Bitrián Alberto, Munárriz Julen
Departamento de Química Física y Analítica, Universidad de Oviedo, Oviedo 33006, Spain.
Fachbereich Biologie, Chemie, Pharmazie, Institut für Chemie und Biochemie - Anorganische Chemie, Freie Universität Berlin, Fabeckstraße 34/36, Berlin 14195, Germany.
Inorg Chem. 2025 Jan 20;64(2):1064-1074. doi: 10.1021/acs.inorgchem.4c04603. Epub 2025 Jan 3.
The pentafluoroorthotellurate group (-OTeF, teflate) exhibits high electron-withdrawing properties. Indeed, it is often used as a bulky substitute for fluoride due to its high chemical stability and larger size, which reduces its tendency to act as a bridging ligand. These characteristics make it a valuable ligand in synthetic chemistry, facilitating the preparation of molecular structures analogous to polymeric fluoride-based compounds. In this study, we explore the electronic structure of the teflate group by using advanced Quantum Chemical Topology (QCT) methods to better understand its bonding nature and compare its group electronegativity with that of the halogens. For that, we examine XOTeF systems (X = F, Cl, Br, I) and decompose X-OTeF interactions into classical (ionic) and exchange-correlation (covalent) contributions by using interacting quantum atoms (IQA) energy decomposition scheme. We also conduct a detailed analysis of electron distribution by utilizing the statistical framework of electron distribution functions (EDFs) and examine the electron localization function (ELF), electron density, and reduced density gradient scalar functions, as well as delocalization indices and QTAIM charges. The results show that the electron-withdrawing properties of the teflate group are comparable to those of fluorine, albeit slightly lower. Moreover, its internal bonding is primarily ionic. Additionally, we compare -OTeF with other O-donor groups, demonstrating that the electron-withdrawing properties within OEF (E = S, Se, Te) systems are nearly identical, and these groups show a higher group electronegativity than OCF, OC(CF), and OCF.
五氟原碲酸根基团（-OTeF，即碲酸根）具有很强的吸电子性质。实际上，由于其高化学稳定性和较大的尺寸，它常被用作氟化物的庞大取代基，这降低了它作为桥连配体的倾向。这些特性使其成为合成化学中有价值的配体，有助于制备类似于基于氟化物的聚合物化合物的分子结构。在本研究中，我们通过使用先进的量子化学拓扑（QCT）方法来探索碲酸根基团的电子结构，以便更好地理解其键合性质，并将其基团电负性与卤素的进行比较。为此，我们研究了XOTeF体系（X = F、Cl、Br、I），并通过使用相互作用量子原子（IQA）能量分解方案将X - OTeF相互作用分解为经典（离子）和交换相关（共价）贡献。我们还利用电子分布函数（EDF）的统计框架对电子分布进行了详细分析，并研究了电子定域函数（ELF）、电子密度和约化密度梯度标量函数，以及离域指数和QTAIM电荷。结果表明，碲酸根基团的吸电子性质与氟相当，尽管略低。此外，其内部键合主要是离子性的。此外，我们将 - OTeF与其他氧供体基团进行了比较，表明OEF（E = S、Se、Te）体系中的吸电子性质几乎相同，并且这些基团显示出比OCF、OC(CF)和OCF更高的基团电负性。
