Boussouf K, Boulmene R, Prakash M, Komiha N, Taleb M, Mogren Al-Mogren M, Hochlaf M
Université Paris-Est, Laboratoire Modélisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 bd Descartes, 77454 Marne-la-Vallée, France.
Phys Chem Chem Phys. 2015 Jun 14;17(22):14417-26. doi: 10.1039/c4cp06108j.
In the present work, we investigate the bonding, structures, stability and spectra of the Zn(q+)Im (where q = 0, 1, and 2) complexes, which are zeolitic imidazolate frameworks (ZIFs) and Zn-enzyme sub-units. Through a benchmark work, we used density functional theory (DFT) with dispersion correction and standard and explicitly correlated ab initio methods. For neutral Zn(0)Im, we found two stable weakly bound forms: (i) a stacked ferrocene-like complex and (ii) a planar σ-type complex. This is the first report of the Zn(0) organic compound with a stacked ferrocene-like structure. The most stable isomers of the ionic species consist of σ-type bonded complexes. The role of various types of covalent and noncovalent interactions within these complexes is discussed after performing vibrational, NBO, charge and orbital analyses. For neutral species, van der Waals (vdWs) and charge transfer through covalent as well as noncovalent interactions are in action; whereas the bonding is dominated by charge transfer from Zn to Im within the ionic species. These findings are important to understand, at the microscopic level, the structure and the bonding within the ZIFs and the Zn-enzymes. Moreover, we establish the ability and reliability of M05-2X and PBE0 functionals for the simultaneous correct description of covalent and noncovalent interactions since this DFT leads to a close agreement with post-Hartree-Fock methods. The newly launched M11 functional is also suited for the description of noncovalent interactions. Therefore, M05-2X and PBE0 functionals are recommended for studying the larger complexes formed by Zn and Im, such as the ZIFs and Zn-enzymes.
在本工作中，我们研究了Zn(q+)Im（其中q = 0、1和2）配合物的键合、结构、稳定性和光谱，这些配合物是沸石咪唑酯骨架（ZIFs）和锌酶亚基。通过一项基准工作，我们使用了带有色散校正的密度泛函理论（DFT）以及标准和显式相关的从头算方法。对于中性的Zn(0)Im，我们发现了两种稳定的弱结合形式：（i）一种堆叠的类二茂铁配合物和（ii）一种平面σ型配合物。这是关于具有堆叠类二茂铁结构的Zn(0)有机化合物的首次报道。离子物种的最稳定异构体由σ型键合配合物组成。在进行振动、NBO、电荷和轨道分析后，讨论了这些配合物中各种类型的共价和非共价相互作用的作用。对于中性物种，范德华（vdW）相互作用以及通过共价和非共价相互作用的电荷转移都在起作用；而在离子物种中，键合主要由从Zn到Im的电荷转移主导。这些发现对于在微观层面理解ZIFs和锌酶的结构与键合很重要。此外，我们确立了M05 - 2X和PBE0泛函同时正确描述共价和非共价相互作用的能力和可靠性，因为这种DFT方法与后哈特里 - 福克方法得出了相近的结果。新推出的M11泛函也适用于描述非共价相互作用。因此，推荐使用M05 - 2X和PBE0泛函来研究由Zn和Im形成的更大配合物，如ZIFs和锌酶。
