A Digallane Gold Complex with a 12-Electron Auride Center: Synthesis and Computational Studies

Abstract

The reaction of Power's digalladeltacyclane with Au(PPh 3 )Cl led to formation of a digallium gold complex (2) with both chloride and gold bridging between two gallium atoms. The bonding parameters from the solid-state structure of 2 suggested a 12e − Au center stabilized by weakly coordinated aryl groups. DFT calculations at the M05-2X/[LANL2TZ(f),6-311G(d)] level indicated a Ga−Au−Ga banana bond with no bonding interactions between gallium atoms. The gold carries an NBO charge of −0.0956 e − and is best viewed as an auride. The weak intramolecular interactions between Au p orbitals and σ C−C and σ C−H bonds of the adjacent aromatic rings amount to significant stabilization of the electron-deficient gold center. The digallium complex 2 represents the first structural example of a 12 e − organometallic auride complex, demonstrating its pseudohalide/hydride nature in bonding.

Phosphine-Stabilized Hidden Ground States in Gold Clusters Investigated via a Aun(PH3)m Database

“…Relevant gold kernel geometries are identified and show large differences in calculated energies above the hull as a function of ligation. Importantly, we find that structures that have been observed experimentally (CSD IDs: 2023935, 42 668368, 43 1123093, 44 1123094, 45 1123095 46 ) were correctly identified as ground states only with m = 6 and m = 7. Notably, these structures are 200 and 470 meV above the hull, respectively, in their bare, unligated states.…”

A boron, nitrogen-containing heterocyclic carbene (BNC) as a redox active ligand: synthesis and characterization of a lithium BNC-aurate complex

“…Only more recently, electropositive group 13 based organo-main group ligands have been used to access and stabilize electron-rich gold centers as aurate and auride complexes. 16,17 The long-standing challenge for accessing electron-rich aurate complexes lies in the difficulty in invoking gold-ligand multiple bonds with M-L π interactions, which is usually the most effective strategy to compensate for excessive electron density and charges on metal by ligands. Having fully filled and exceptionally low-lying 5d orbitals, electronic modulation by π-donating [18][19][20]21 or π-withdrawing ligands on a gold(I) centre is particularly difficult.…”

“…Only more recently, electropositive group 13 based organo-main group ligands have been used to access and stabilize electron-rich gold centers as aurate and auride complexes. 16,17…”