Synthesis and Characterization of Heterobimetallic Complexes with Direct Cu–M Bonds (M = Cr, Mn, Co, Mo, Ru, W) Supported byN-Heterocyclic Carbene Ligands: A Toolkit for Catalytic Reaction Discovery

Abstract

Building upon the precedent of catalytically active (NHC)Cu-FeCp(CO)2 complexes, a series of (NHC)Cu-[M] complexes were synthesized via the addition of Na(+)[M](-) reagents to (NHC)CuCl synthons. The different [M](-) anions used span a range of 7 × 10(7) relative nucleophilicity units, allowing for controlled variation of nucleophile/electrophile pairing in the heterobimetallic species. Direct Cu-M bonds (M = Cr, Mn, Co, Mo, Ru, W) formed readily when the bulky IPr carbene was used as a support. Crystallographic characterization and computational examination of these complexes was conducted. For the smaller IMes carbene, structural isomerism was observed when using the weakest [M](-) nucleophiles, with (IMes)Cu-[M] and {(IMes)2Cu}{Cu[M]2} isomers being observed in equilibrium. Collectively, the series of complexes provides a toolbox for catalytic reaction discovery with precise control of structure-function relationships.

Organometallic Probe for the Electronics of Base‐Stabilized Group 11 Metal Cations

“…One characteristict rait of heterobimetallics in which the anionic bonding partner bears CO ligandsi st he formation of close contacts between the incoming cationic fragment and one or more of these COs (Figure 2a). [26,27] These interactions are found in each of the nine isolated compounds, manifest in moderately short OCÀ . Md istances, slight deviations from the ideal linearityo ft he MnÀCÀOa ngle, and elongated MnÀCO bondsf or the affected CO ligands (see Ta bleS2i nt he Supporting Information).…”

“…Eur.J.2015, 21,12347 -12356 www.chemeurj.org metal-metal bonding ( Figure 2a). Both gold and silver phosphines have shown the capacity to form these structures, [25] and recently Mankad and co-workers published an array of bimetallicc ompounds containing NHC-stabilized copper, [26] thereby supplementing the existing literature on amine-and phosphine-stabilized copperh eterobimetallics. [27] Calculations on anion 1 indicate that most of the negative chargei sl ocalized on the manganese atoms (À0.69, NaturalP opulation Analysis), [20b] making these sites potentially nucleophilic.…”

Transition-Metal-Free Formation of C–E Bonds (E = C, N, O, S) and Formation of C–M Bonds (M = Mn, Mo) from N-Heterocyclic Carbene Mediated Fluoroalkene C–F Bond Activation

“…The following salts were prepared according to literature procedures: sodium 1,2,4-triazolate, 37 sodium pyrazolate, 37 sodium (2 S )-2-pyrrolidinecarboxylate ([Na][L-proline]), 38 sodium 8-oxyquinoline, 39 [Na][Mn(CO) 5 ], 40 and [Na][CpMo(CO) 3 ]. 40 The synthesis of SIMes=CF(CF 2 CF 3 ) ( 1a ), SIMes=CF(CF 2 H) ( 1b ), and [SIMes-CF=CF(CF 3 )][OTf] ( 2 ) has been previously described. 15 1 H, 19 F, and 19 F{ 1 H} NMR spectra were recorded on either a 300 MHz Bruker Avance or a 300 MHz Bruker Avance II spectrometer at room temperature.…”

Titelbild: Orthogonal Light‐Induced Self‐Assembly of Nanoparticles using Differently Substituted Azobenzenes (Angew. Chem. 42/2015)

“…Calculations on anion 1 indicate that most of the negative charge is localized on the manganese atoms (−0.69, Natural Population Analysis),20b making these sites potentially nucleophilic. In Mankad’s adduct of [IPr‐Cu] + (IPr=1,3‐(diisopropyl)imidazol‐2‐ylidene) and [Mn(CO) 5 ] − (Figure 2a), the MnCu bond (2.415(1) Å)26b is shorter than the average MnCu distances in 1⋅Cu PCy3 (2.692 Å), 1⋅Cu ITol (2.686 Å), and 1⋅Cu CAAC (2.772 Å); however, each of the observed MnCu distances in the structures in Figure 1 fall either at or below the sum of the covalent radii for copper and manganese (2.71 Å), as determined by Cordero et al.,28 with the exception of one of the MnCu bonds in 1⋅Cu CAAC , which is a modest 4 % greater than the sum of the radii. The same is true for the remainder of the symmetrical structures, 1⋅Ag PCy3 , 1⋅Au PCy3 , and 1⋅Ag CAAC , in which no MMn distance was found to be more than 5 % longer than the sum of the covalent radii.…”