Synthesis, Structural and Spectroscopic Characterization of Cr^III, Fe^III, Co^III, Ni^II and Cu^II Complexes with an Asymmetric 1,3,4‐Thiadiazole Ligand

Abstract

The reaction of the new asymmetric 1,3,4-thiadiazole-based ligand 2-[(5-ethylthio-1,3,4-thiadiazol-2-yl)hydrazonomethyl]phenol (H 1 ETHP) with various third-row transition metal salts resulted in the formation of six new mononuclear complexes [Cr(ETHP) 2 ]ClO 4 (1), [Fe(ETHP) 2 ][FeCl 4 ] (2), [Co(ETHP)(ETHP -H )] (3), [Ni(ETHP)(H 1 ETHP)]Cl (4), [Ni(ETHP)(H 1 ETHP)](ClO 4 ) (5), [Ni(ETHP)(H 1 ETHP)]Br (6), and one tetranuclear complex [Cu 2 Cl 3 (ETHP)(H 1 ETHP)] 2 (7). H 1 ETHP and all complexes have been analyzed by single crystal X-ray diffraction. Structural analysis of 1-6 reveals complexes of the [ML 2 ] n+type (n = 0,1), in which the mono anionic ligand ETHP coordinates in a tridentate NNO fashion via its imine, thiadiazole and [a]

New Type of Neutral Binuclear Spin‐Crossover Complex of Iron(III) with Twist of Two Disulfide Bridges as a Product of Electrochemical Oxidation of [FeIII(5Cl‐thsa)2]− Anions

“…The observed Fe−N(H) distances correspond to the high spin state of the complex according to the literature data for the octahedral FeN 4 O 2 complexes with different ligands [30] . Up to date, the only two Fe complexes with modified thsa chelating ligands in FeN 4 O 2 coordination mode are known [31,32] . They both are high‐spin and also have similar Fe−N/O bond lengths as in 2 .…”

“…[30] Up to date, the only two Fe complexes with modified thsa chelating ligands in FeN 4 O 2 coordination mode are known. [31,32] They both are high-spin and also have similar FeÀ N/O bond lengths as in 2. An additional evidence of the HS state of the complex 2 is given by an essential distortion within the coordination Fe III octahedron (NÀ FeÀ O and NÀ FeÀ N angles are far from 180°, Table S3; the distortion parameter Σ, which is a measure of the net angular deviation from the idealized octahedral geometry, equals 118.1/ 116.9°for two molecular sites, Table S4).…”

Crystal structure of tetra-μ-acetato-bis[(5-amino-2-methylsulfanyl-1,3,4-thiadiazole-κN 1)copper(II)]

“…Their diverse biological activity possibly arises from the presence of the NCS moiety in the molecule (Oruç et al, 2004). An interesting feature of the metal-ligand chemistry of these compounds is that the complexes can be either mononuclear (Tzeng et al, 2004;Varna et al, 2018;Qiu et al, 2014) or binuclear (Deckert et al, 2016;Ardan et al, 2017). A search of the Cambridge Structural Database (CSD Version 5.4, update of February 2019; Groom et al, 2016) revealed that although crystal structures have been reported for complexes of either 1,3,4-thiadiazole derivatives or OAc with a number of metal ions, including zinc, copper, nickel, manganese, cadmium, cobalt and palladium, no examples are known of mixed-ligand metal complexes containing both 1,3,4-thiadiazole derivatives and OAc.…”

Regioselective Acetoxylation of Terminal Olefins Using a Palladium(II)–Thiadiazole Catalyst

“…Besides, the structural characterization of the thiadiazole‐metal complexes have also been studied. Rentschler et al reported the cooperation of the asymmetric 1,3,4‐thiadiazole‐based ligand with third‐row transition metal salts (Cr III , Fe III , Co III , Ni II and Cu II ) . Bharty et al defined the square‐planar geometry of the 2‐mercapto‐5‐methyl‐1,3,4‐thiadiazole palladium(II) compound .…”