A theoretical study of M-M′ polar-covalent bonding in heterobimetallic multinuclear organometallic complexes of monovalent group 11 metal centres

• Published in: Physical chemistry chemical physics : PCCP Vol. 25; no. 11; pp. 7642 - 7647
• Main Authors: Rabaâ, Hassan, Sundholm, Dage, Omary, Mohammad A
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 15.03.2023
• Subjects: Bonding strength; Chemical bonds; Copper; Density functional theory; Empirical analysis; Gold; Luminescence; Optical properties; Orbitals; Organic light emitting diodes; Silver
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/d2cp04774h

Complexes with closed-shell (d 10 -d 10 ) 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 10 -d 10 ) centres. The investigated molecules include pentanuclear complexes with M or M′ = Cu( i ), Ag( i ), or Au( i ) and Mes = 2,4,6-Me 3 C 6 H 2 . 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 ab initio 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 ( n + 1)s and ( n + 1)p orbitals of M with the ( n 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. Complexes with closed-shell (d 10 -d 10 ) interactions have been studied for their interesting luminescence properties in organic light-emitting diode (OLED) devices.