Rabaâ Hassan, Sundholm Dage, Omary Mohammad A
Department of Chemistry, Ibn Tofail University, ESCTM, P.O. Box 133, 14000, Kenitra, Morocco.
Department of Chemistry, University of North Texas, P.O. Box 305070, Denton, TX, 76203, USA.
Phys Chem Chem Phys. 2023 Mar 15;25(11):7642-7647. doi: 10.1039/d2cp04774h.
Complexes with closed-shell (d-d) interactions have been studied for their interesting luminescence properties in organic light-emitting diode (OLED) devices. The present computational study aims at understanding the chemical bonding/interactions in a series of molecules with unusually short metal-metal bond distances between monovalent coinage-metal (d-d) centres. The investigated molecules include pentanuclear complexes with M or M' = Cu(I), Ag(I), or Au(I) and Mes = 2,4,6-MeCH. In such complexes, the M-M' distances are up to 50-100 pm shorter than typical metallophilic bonds in homometallic analogues. Characterization and analysis of the chemical bond strength was performed using methods, density functional theory methods including a semi-empirical treatment of dispersion interactions (DFT-D3) and semi-empirical calculations at the extended Hückel theory (EHT) level. Population analysis suggests that hybridization occurs by mixing the ( + 1)s and ( + 1)p orbitals of M with the (d) orbitals of M'. The orbital mixing plays a pivotal role in the polydentated polar-covalency/dative M-M' bonds that distinguish this bonding from the weaker metallophilic interactions.
具有闭壳层（d-d）相互作用的配合物因其在有机发光二极管（OLED）器件中有趣的发光特性而受到研究。目前的计算研究旨在理解一系列在单价货币金属（d-d）中心之间具有异常短的金属-金属键距离的分子中的化学键合/相互作用。所研究的分子包括M或M' = Cu（I）、Ag（I）或Au（I）且Mes = 2,4,6-MeCH的五核配合物。在这类配合物中，M-M'距离比同金属类似物中的典型亲金属键短50 - 100 pm。使用包括色散相互作用的半经验处理（DFT-D3）的密度泛函理论方法以及扩展休克尔理论（EHT）水平的半经验计算对化学键强度进行了表征和分析。布居分析表明，通过将M的（ + 1）s和（ + 1）p轨道与M'的（d）轨道混合发生杂化。轨道混合在多齿极性共价/配位M-M'键中起关键作用，这种键合将这种键合与较弱的亲金属相互作用区分开来。
