Thioether sulfur-bound [Cu₂] complexes showing catechol oxidase activity and DNA cleaving behaviour

Abstract

Ligand backbone alteration leads to different mechanisms for catecholase activity and order of interaction with DNA molecules.

Entrapment of a Pseudo‐Tetrahedral CoII Center by Thioether Sulfur Bound {Co2(μ‐L)} Fragments: Synthesis, Field‐Induced Single‐Ion Magnetism and Catechol Oxidase Mimicking Activity

“…Herein we propose the coordination of 3,5-DTBCH 2 in its mono-deprotonated form as 3,5-DTBCHt oo nly one of the Co III centers due to the generation of H 2 O 2 . [20,41] One electron oxidation of the substrate accompanied by concomitant reduction of Co III to Co II results in the semiquinone radical bound intermediate species{ Co II Hence,a lthough the {Co III Co III (m-L)} species still catalyzes the oxidation of the substrate, the major contribution comesf rom the {Co III (H 2 L)(CH 3 COO)(H 2 O) 2 }s pecies( Scheme 2b). Subsequent oxidationo fD TSQ and formation of H 2 O 2 takes place by ap rocess similart ot hat described earlier.T he kinetic experiments revealthat the k cat values in MeCN are much lower compared to those in MeOH for both 1 and 2.T his can be attributed to the predominance of the monomeric speciesi nthe catalytic oxidation process in MeCN.…”

“…Upon addition of 3,5‐DTBCH 2 the dimeric fragment possibly forms a 1:1 adduct with the substrate identified as the shoulder at 309 nm from UV‐vis experiments. Herein we propose the coordination of 3,5‐DTBCH 2 in its mono‐deprotonated form as 3,5‐DTBCH to only one of the Co III centers due to the generation of H 2 O 2 . One electron oxidation of the substrate accompanied by concomitant reduction of Co III to Co II results in the semiquinone radical bound intermediate species {Co II Co III ( μ ‐L)}(DTSQ)} (Scheme a).…”

“…The synthesis, growth of crystals, X‐ray structure determinations, magnetic properties and catechol oxidation activity of these complexes are described and discoursed. Recently we have shown that use of H 3 L resulted only {Cu 2 L(OH)} 2+ based complexes without showing any kind of self‐aggregation around nucleating anions or metal ions from the reaction medium . Catalytic catechol oxidation studies in different solvent medium showed the influence of the ligand alcohol arm on the mechanism of substrate oxidation under aerobic conditions.…”

“…Recently we have shown that use of H 3 Lr esulted only {Cu 2 L(OH)} 2 + based complexes without showing anyk ind of self-aggregationa round nucleating anions or metal ions from the reactionm edium. [20] Catalytic catechol oxidation studies in different solvent medium showed the influence of the ligand alcohol arm on the mechanism of substrate oxidation under aerobic conditions. In this work we have investigated the solventd ependent catalytic potency of {Co III 2 L} fragments generated in solution towards oxidationo f3 ,5-DTBCH 2 .…”

Exploitation of Structure‐Property Relationships towards Multi‐Dimensional Applications of a Paddle‐Wheel Cu(II) Compound

“…Therefore, designing of suitable coordination compounds for imitating the active sites of bio-relevant metalloenzymes like catechol oxidase has fascinated huge devotion over the years. [27][28][29] Herein, we have synthesized a novel Cu(II) based paddle-wheel compound [Cu 2 (nac) 4 (4-nvp) 2 ] (1) (Hnac=3-(1naphthyl)acrylic acid and 4-nvp=4-(1-naphthylvinyl)pyridine), which possesses the above mentioned properties for multipurpose applications. The compound shows electrical conductivity in the semiconducting regime that exhibits non-linear behavior with good rectification and can be used as Schottky barrier diode.…”