Copper–Ligand Cooperativity in H2 Activation Enables the Synthesis of Copper Hydride Complexes

Copper(I) complexes of a new participative triphosphane ligand (<b>2^H</b>) have been prepared and structurally characterized, in particular [Cu(<b>2^H</b>)I] and [Cu(<b>2</b>)]₂. Hydrogenation of the latter species afforded the trimetallic hydride species [Cu₃(<b>2</b>)₂(µ-H)] or in the presence of BEt₃, [Cu(<b>2^H</b>)(HBEt₃)]. Their formation evidences transient formation of [Cu(<b>2^H</b>)H] formed by hydrogenolysis of the Cu‒<br>N bond of [Cu(<b>2</b>)]₂. [Cu(<b>2^H</b>)(HBEt₃)] behaves like a hydride complex and inserts CO₂ to yield the formate product [Cu(<b>2^H</b>)(O₂CH)].<br>

Copper-hydride nanoclusters with enhanced stability by N-heterocyclic carbenes

Copper-hydrides have been intensively studied for a long time due to their utilization in a variety of technologically important chemical transformations. Nevertheless, poor stability of the species severely hinders its isolation, storage and operation, which is worse for nano-sized ones. We report here an unprecedented strategy to access to ultrastable copper-hydride nanoclusters (NCs), namely, using bidentate N-heterocyclic carbenes as stabilizing ligands in addition to thiolates. In this work, a simple synthetic protocol was developed to synthesize the first large copper-hydride nanoclusters (NCs) stabilized by N-heterocyclic carbenes (NHCs). The NC, with the formula of Cu31(RS)25(NHC)3H6 (NHC = 1,4-bis(1-benzyl-1H-benzimidazol-1-ium-3-yl) butane, RS = 4-fluorothiophenol), was fully characterized by high resolution Fourier transform ion cyclotron resonance mass spectrum, nuclear magnetic resonance, ultra-violet visible spectroscopy, density functional theory (DFT) calculations and single-crystal X-ray crystallography. Structurally, the title cluster exhibits unprecedented Cu4 tetrahedron-based vertex-sharing (TBVS) superstructure (fusion of six Cu4 tetrahedra). Moreover, the ultrahigh thermal stability renders the cluster a model system to highlight the power of NHCs (even other carbenes) in controlling geometrical, electronic and surface structure of polyhydrido copper clusters.

Copper–Ligand Cooperativity in H2 Activation Enables the Synthesis of Copper Hydride Complexes

Copper(I) complexes of a new participative triphosphane ligand (<b>2^H</b>) have been prepared and structurally characterized, in particular [Cu(<b>2^H</b>)I] and [Cu(<b>2</b>)]₂. Hydrogenation of the latter species afforded the trimetallic hydride species [Cu₃(<b>2</b>)₂(µ-H)] or in the presence of BEt₃, [Cu(<b>2^H</b>)(HBEt₃)]. Their formation evidences transient formation of [Cu(<b>2^H</b>)H] formed by hydrogenolysis of the Cu‒<br>N bond of [Cu(<b>2</b>)]₂. [Cu(<b>2^H</b>)(HBEt₃)] behaves like a hydride complex and inserts CO₂ to yield the formate product [Cu(<b>2^H</b>)(O₂CH)].<br>

Copper–Ligand Cooperativity in H2 Activation Enables the Synthesis of Copper Hydride Complexes

Copper(I) complexes of a new participative triphosphane ligand (<b>2^H</b>) have been prepared and structurally characterized, in particular [Cu(<b>2^H</b>)I] and [Cu(<b>2</b>)]₂. Hydrogenation of the latter species afforded the trimetallic hydride species [Cu₃(<b>2</b>)₂(µ-H)] or in the presence of BEt₃, [Cu(<b>2^H</b>)(HBEt₃)]. Their formation evidences transient formation of [Cu(<b>2^H</b>)H] formed by hydrogenolysis of the Cu‒<br>N bond of [Cu(<b>2</b>)]₂. [Cu(<b>2^H</b>)(HBEt₃)] behaves like a hydride complex and inserts CO₂ to yield the formate product [Cu(<b>2^H</b>)(O₂CH)].<br>

A stable well-defined copper hydride cluster consolidated with hemilabile phosphines

Copper hydrides are very useful in hydrogenation reactions. We report a stable Stryker-type copper hydride reagent protected by hemilabile phosphines: [Cu8H6(dppy)6](OTf)2 (Cu8-H, dppy = diphenylphoshpino-2-pyridine). The metal core of this...

Dissection of a bicapped octahedral copper hydride cluster by halides or pseudohalides to form two different classes of racemic tetrahedral copper hydride clusters and the discovery of an unusual auto deracemization in the crystallization process

Three series of copper hydride clusters [Cu8H6L6]2+ (1), [Cu4HX2L4]+ where X− = Cl− (2a), Br− (2b), I− (2c), N3− (2d) and SCN− (2e), and [Cu4HX3L3] where X− = Br− (3b)...

Hydrogenation reactions catalyzed by HN(CH2CH2PR2)2-ligated copper complexes

Hydrogenation of aldehydes and ketones can be catalyzed by a PNP-ligated copper hydride that is accessible from the copper borohydride or bromide complex or the copper hydride cluster.