Revisiting the Bonding Model for Gold(I) Species: The Importance of Pauli Repulsion Revealed in a Gold(I)‐Cyclobutadiene Complex. Issue 22 (30th March 2022)

• Record Type: Journal Article
• Authors: Wong, Zeng Rong; Schramm, Tim K.; Loipersberger, Matthias; Head‐Gordon, Martin; Toste, F. Dean
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-30
• Subjects: Bond Theory -- Cyclobutadiene -- Density Functional Calculations -- Energy Decomposition Analysis -- Gold; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202202019
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Understanding the bonding of gold(I) species has been central to the development of gold(I) catalysis. Herein, we present the synthesis and characterization of the first gold(I)‐cyclobutadiene complex, accompanied with bonding analysis by state‐of‐the‐art energy decomposition analysis methods. Analysis of possible coordination modes for the new species not only confirms established characteristics of gold(I) bonding, but also suggests that Pauli repulsion is a key yet hitherto overlooked element. Additionally, we obtain a new perspective on gold(I)‐bonding by comparison of the gold(I)‐cyclobutadiene to congeners stabilized by p‐, d‐, and f‐block metals. Consequently, we refine the gold(I) bonding model, with a delicate interplay of Pauli repulsion and charge transfer as the key driving force for various coordination motifs. Pauli repulsion is similarly determined as a significant interaction in Au I ‐alkyne species, corroborating this revised understanding of Au I bonding. Abstract : A novel Au I ‐cyclobutadiene complex for which reduced Pauli repulsion yields an η 1 instead of η 4 ‐coordination is presented. This combined experimental and theoretical study motivates a reformulation of the gold(I)‐π‐ligand bonding model to include Pauli repulsion as a key element. Further analysis of gold(I)‐alkynes corroborates this conclusion.