| dc.description.abstract | Carbones are molecules where the central carbon is in the zero oxidation state and possesses two lone pairs of electrons. The first lone pair exhibits strong electron-donating abilities, making carbones effective ligands in coordination chemistry and catalysis involving transition metals.
This thesis explores the use of carbones, specifically carbodicarbene and carbophosphinocarbene, as ligands to form bis-carbone metal complexes with oxidation-resistant gold and focuses on studying the second lone pair of electrons in these complexes. Initially, the bis-carbone gold complexes undergo oxidation with silver bis(trifluoromethanesulfonyl)imide (AgNTf2), targeting the second lone pair of electrons to generate radical gold complexes. These radical complexes are characterized using NMR spectroscopy, EPR spectroscopy, and single-crystal XRD. Notably, the synthesized diradical gold complexes allow for the observation of both NMR and EPR spectra, providing insights into the potential interconversion between singlet and triplet states.
Furthermore, we observed that during the oxidation process to form diradical gold complexes, the carbophosphinocarbene gold complex at first coordinates with the silver reagent via its second lone pair, leading to the formation of a trinuclear heterometallic intermediate. Utilizing the coordinating ability of the second lone pair in bis-carbone gold complexes, we synthesized a series of unique trinuclear heterometallic complexes. Our findings indicate that gold complexes with carbophosphinocarbene as ligands tend to coordinate metals in an anti-arrangement, while those with carbodicarbene prefer a syn-arrangement.
Consequently, we employed these syn- and anti-configured metal complexes as catalysts in various reactions, comparing their catalytic efficiencies. The comparative analysis provides valuable insights into the influence of ligand orientation on catalytic performance. | en_US |