Titanium thiosalicylate complexes: functional metalloligands for the construction of redox-active heterometallic architectures
| Autor: | Isabel Cuadrado, Carolina Hernández, Sonia Bruña, Pilar Terreros, Antonio Otero, Ana M. Rodríguez, María José Ruiz, Rosa Fandos |
|---|---|
| Rok vydání: | 2018 |
| Předmět: |
Thiosalicylic acid
010405 organic chemistry Ligand chemistry.chemical_element 010402 general chemistry 01 natural sciences Medicinal chemistry Redox 0104 chemical sciences Inorganic Chemistry Metal chemistry.chemical_compound Transition metal chemistry visual_art visual_art.visual_art_medium Moiety Derivative (chemistry) Titanium |
| Zdroj: | Dalton Transactions. 47:15391-15398 |
| ISSN: | 1477-9234 1477-9226 |
| Popis: | The titanium complex [TiCp*(thiosal)(thiosalH)] (1) has been synthesised by reaction of [TiCp*Me3], Cp* = η5-C5Me5, with thiosalicylic acid (H2thiosal). Complex 1 reacts with [M(μ-OH)(COD)]2 (M = Rh, Ir) to yield the corresponding early–late heterobimetallic complexes [TiCp*(thiosal)2M(COD)] (M = Rh (2); Ir (3)). Carbon monoxide replaces the COD ligand in 2 and 3 leading to the respective dicarbonyl complexes [TiCp*(thiosal)2M(CO)2] (M = Rh (4); Ir (5)). Compound 4 reacts with PPh3 to yield the monocarbonyl derivative [TiCp*(thiosal)2Rh(CO)(PPh3)] (6). The reaction of compound 1 with LinBu yields the tetrametallic complex [{TiCp*(thiosal)2Li}2(THF)3(H2O)] (7). Compound 7 reacts with [RuCp*Cl(COD)] yielding the heterometallic complex [TiCp*(thiosal)2RuCp*] (8). The molecular structures of compounds 4, 5 and 7 have been studied by X-ray diffraction. From cyclic voltammetric (CV) and square wave voltammetric (SWV) experiments, we observed that attachment of the titanium moiety of precursor 1 to a late transition metal moiety through the sulfur atoms has a significant influence on the reduction behaviour of the Ti(IV) metal centre. Thus, monometallic 1 exhibits an irreversible reduction process at −1.15 V vs. SCE, whereas the CVs of heterobimetallic compounds 2–6 are characterized by the reversible or quasi-reversible one-electron reduction of the Ti(IV)/Ti(III) system, suggesting a significant stabilization of the Ti(III) reduced species. Likewise, substitution of the M(COD) diolefin fragment in 2 and 3 by the M(CO)2 carbonyl-containing moiety (in compounds 4 and 5) leads to a significant anodic shift in the titanium E1/2 reduction redox potentials. |
| Databáze: | OpenAIRE |
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