Synthesis, characterization and DFT calculations of a novel hexanuclear silver(I) cluster-complex containing 4-ethyl-5-pyridin-2-yl-2,4-dihydro-[1,2,4]triazol-3-thione as a result from the cyclization of 2-pyridinformamide N-4-ethylthiosemicarbazone

Synthesis, Characterization and X‐ray Structures of [α‐Diphenylethanedione bis(4‐ethylthiosemicarbazonato)]palladium(II) and 1,2,4‐Triazine‐3‐thione–Zinc(II) Complexes Obtained by Metal‐Induced Cyclization

“…The analytical, spectroscopic, and X-ray diffraction data (see Experimental Section) revealed that H 2 BbTSC-Et is transformed into cyclic 5-ethoxy-4-ethyl-5,6-diphenyl-4,5-dihydro-2H-[1,2,4]-triazine-3-thione (HTa3T-Et) during the complexation reaction. An analogous cyclization of 2-pyridinformamide 4-ethylthiosemicrbazone that is promoted by the presence of silver(I) ions was reported recently by Castiñeiras et al [16] The mother liquor was allowed to stand at 4°C. After several days, crystalline pale yellow needles were isolated, which were identified as the free ligand H 2 BbTSC-Et by Xray diffraction analysis.…”

Metal‐Catalysed Oxidation Processes in Thiosemicarbazones: New Complexes with the Ligand N‐{2‐([4‐N‐Ethylthiosemicarbazone]methyl)phenyl}‐p‐toluenesulfonamide

“…[32] Instead, a new terminal amide NH is incorporated into the skeleton. All these processes ultimately result in the formation of a new [N 4 ] ligand coordinated to two Cu II metal ions in a doubly-deprotonated mode.…”

“…[32,42] Based on a careful analysis of the available data, we surmise that the formation of the triazole ring could be induced by an attack of the oxidising agent on the tail-like thioamide moiety, followed by a single-electron transfer and then a rate-limiting ring-closure step. Alternatively, the thiadiazole heterocycle is formed as a result of an attack of the metal cation on the imine nitrogen atom, followed by a ringclosure step and finally an electron abstraction-dehydrogenation step.…”

Synthesis, crystal structures, and biological activities of 2-thiophene N(4)-methylthiosemicarbazone and its unusual hexanuclear silver(I) cluster

“…The central core Ag 2 S 2 is almost square planar(SAg-S, Ag-S-Ag, 87.43°, 92.57°). Within the ring systems the Ag···Ag distances are 2.966(1), 2.993(1) and 3.197(1) Å, these distances are similar to that in metallic silver (2.889 Å), shorter than the sum of the van der Waals radii of two silver atoms (3.44 Å) [22], suggesting the existence of some metal-metal interaction between the silver atoms. The coordination of a potentially tridentate thiosemicarbazone in silver(I) complex without using its thiophene sulfur is unusual.…”

“…After a careful literature search, we can affirm that thiosemicarbazone silver(I) complexes are scarce [22][23][24]. Therefore, it seemed important for us to fulfil this work.…”