Dahmani R, Ben Yaghlane S, Boughdiri S, Mogren Al-Mogren M, Prakash M, Hochlaf M
Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France; Laboratoire de Spectroscopie Atomique, Moléculaire et Applications - LSAMA, Université de Tunis El Manar, Tunis, Tunisia; Unité de Recherche Physico-Chimie des Matériaux à l'Etat Condensé, Département de Chimie, Faculté des Sciences de Tunis, Université Tunis El Manar, Tunis 2092, Tunisia.
Laboratoire de Spectroscopie Atomique, Moléculaire et Applications - LSAMA, Université de Tunis El Manar, Tunis, Tunisia.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Mar 15;193:375-384. doi: 10.1016/j.saa.2017.12.017. Epub 2017 Dec 6.
At present, we investigate the structures, the stability, the bonding and the spectroscopy of the Zn-triazole complexes (Zn-Tz), which are subunits of triazolate based porous materials and Zn-enzymes. This theoretical work is performed using ab initio methods and density functional theory (DFT) where dispersion correction is included. Through these benchmarks, we establish the ability and reliability of M05-2X+D3 and PBE0+D3 functionals for the correct description of Zn-Tz bond since these DFTs lead to close agreement with post Hartree-Fock methods. Therefore, M05-2X+D3 and PBE0+D3 functionals are recommended for the characterization of larger organometallic complexes formed by Zn and N-rich linkers. For Zn-Tz, we found two stable σ-type complexes: (i) a planar structure where Zn links to unprotonated nitrogen and (ii) an out-of-plane cluster where carbon interacts with Zn. The most stable isomers consist on a coordinated covalent bond between the lone pair of unprotonated nitrogen and the vacant 4s orbital of Zn. The roles of covalent interactions within these complexes are discussed after vibrational, NBO, NPA charges and orbital analyses. The bonding is dominated by charge transfer from Zn to Tz and intramolecular charge transfer, which plays a vital role for the catalytic activity of these complexes. These findings are important to understand, at the microscopic level, the structure and the bonding within triazolate based macromolecular porous materials and Zn-enzymes.
目前，我们研究了锌-三唑配合物（Zn-Tz）的结构、稳定性、键合和光谱性质，它们是基于三唑酸盐的多孔材料和锌酶的亚基。这项理论工作采用了包含色散校正的从头算方法和密度泛函理论（DFT）。通过这些基准测试，我们确立了M05-2X+D3和PBE0+D3泛函对于正确描述Zn-Tz键的能力和可靠性，因为这些DFT与后哈特里-福克方法的结果非常吻合。因此，推荐使用M05-2X+D3和PBE0+D3泛函来表征由锌和富氮连接体形成的更大的有机金属配合物。对于Zn-Tz，我们发现了两种稳定的σ型配合物：（i）一种平面结构，其中锌与未质子化的氮相连；（ii）一种面外簇结构，其中碳与锌相互作用。最稳定的异构体由未质子化氮的孤对电子与锌的空4s轨道之间的配位共价键组成。在进行振动、NBO、NPA电荷和轨道分析之后，讨论了这些配合物中共价相互作用的作用。键合主要由从锌到三唑的电荷转移和分子内电荷转移主导，这对这些配合物的催化活性起着至关重要的作用。这些发现对于在微观层面理解基于三唑酸盐的大分子多孔材料和锌酶的结构和键合非常重要。
