Heterobimetallic complexes of IrM (M = FeII, CoII, and NiII) core and bridging 2-(diphenylphosphino)pyridine: electronic structure and electrochemical behavior. Issue 30 (21st July 2020)

• Record Type: Journal Article
• Authors: Cherepakhin, Valeriy; Hellman, Ashley; Lan, Zhenzhuo; Mallikarjun Sharada, Shaama; Williams, Travis J.
• Is Part Of: Dalton transactions. Volume 49:Issue 30(2020)
• Page Start: 10509
• Page End: 10515
• Publication Date: 2020-07-21
• Subjects: Chemistry, Inorganic -- Periodicals; Chemistry, Physical and theoretical -- Periodicals; Chemistry, Inorganic -- Periodicals; 546.05
• DOI: 10.1039/d0dt01801e
• Languages: English
• ISSNs: 1477-9226

Abstract

Abstract : Novel heterobimetallic complexes were studied by spectroscopic, electrochemical, and computational methods to understand the nature of iridium-metal bonding. Abstract : Three complexes based on an Ir–M (M = Fe II, Co II, and Ni II ) heterobimetallic core and 2-(diphenylphosphino)pyridine (Ph2 PPy) ligand were synthesized via the reaction of trans -[IrCl(CO)(Ph2 PPy)2 ] and the corresponding metal chloride. Their structures were established by single-crystal X-ray diffraction as [Ir(CO)(μ-Cl)(μ-Ph2 PPy)2 FeCl2 ]·2CH2 Cl2 (2 ), [IrCl(CO)(μ-Ph2 PPy)2 CoCl2 ]·2CH2 Cl2 (3 ), and [Ir(CO)(μ-Cl)(μ-Ph2 PPy)2 NiCl2 ]·2CH2 Cl2 (4 ). Time-dependent DFT computations suggest a donor–acceptor interaction between a filled 5dz 2 orbital on iridium and an empty orbital on the first-row metal atom, which is supported by UV-vis studies. Magnetic moment measurements show that the first-row metals are in their high-spin electronic configurations. Cyclic voltammetry data show that all the complexes undergo irreversible decomposition upon either reduction or oxidation. Reduction of 4 proceeds through an ECE mechanism. While these complexes are not stable to electrocatalysis conditions, the data presented here refine our understanding of the bonding synergies of the first-row and third-row metals.