Imidazol(in)ium-2-Thiocarboxylate Zwitterion Ligands: Structural Aspects in Coordination Complexes

Abstract

Azolium-2-thiocarboxylate zwitterion ligands have emerged as a promising class of compounds in the field of coordination chemistry due to their unique structural features and versatile applications. These ligands are characterized by a positively charged azolium ring and a negatively charged thiocarboxylate moiety, making them capable of forming stable coordination complexes with various metal ions. One of the key structural aspects that make these ligands attractive for coordination chemistry is their ability to adopt diverse coordination modes with metal centers. The nature of these ligands enables them to engage in both monodentate and bidentate coordination, resulting in the formation of chelated complexes with enhanced stability and controlled geometry or the formation of polynuclear structures. This versatility in coordination behavior allows for the design of tailored ligands with specific metal-binding preferences, enabling the creation of unique and finely tuned coordination architectures. The azolium-2-thiocarboxylate zwitterionic ligands offer a promising platform for the design of coordination complexes with diverse structural architectures.

Coordination of azol(in)ium dithiocarboxylate ligands to Au(iii): unexpected formation of a novel family of cyclometallated Au(iii) complexes, DFT calculations and catalytic studies

“…2). 9 Even though the potential of these ligands has been studied with a certain number of transition metals, 10 the presence of coordination complexes of dithiocarboxylate azolium ligands and gold in the literature is very limited. The first report dates back to 1987, when Borer et al described the formation of Au( i ) complexes by reaction of dithiocarboxylate azolium ligands and NaAuCl 4 ·2H 2 O.…”

Homoleptic ruthenium(ii) complexes bearing imidazol(in)ium-2-dithiocarboxylate ligands: synthesis, characterization, and redox properties

“…Although NHC·CS 2 zwitterions are strong donors that swiftly form robust M–S bonds with a broad range of metal centers, their coordination chemistry has long remained underexploited. 7 In the late 1980s, Borer et al showed that 1,3-dimethylimidazolium-2-dithiocarboxylate (IMe·CS 2 ) formed stable complexes with a range of transition metal halides or nitrates, but the exact nature of the products obtained remained highly speculative. 8 Since the new millennium, we and others have investigated in more detail the various binding modes of NHC·CS 2 zwitterions with diverse metals, such as manganese, 9 rhenium, 10,11 ruthenium, 11–15 osmium, 14 palladium, 16 copper, 17–19 or gold 20 (see Chart 1 for a few selected examples).…”