Issue 43, 2018

Titanium thiosalicylate complexes: functional metalloligands for the construction of redox-active heterometallic architectures

Abstract

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.

Graphical abstract: Titanium thiosalicylate complexes: functional metalloligands for the construction of redox-active heterometallic architectures

Supplementary files

Article information

Article type
Paper
Submitted
28 jun 2018
Accepted
27 sep 2018
First published
11 okt 2018

Dalton Trans., 2018,47, 15391-15398

Titanium thiosalicylate complexes: functional metalloligands for the construction of redox-active heterometallic architectures

R. Fandos, S. Bruña, C. Hernández, A. Otero, A. Rodríguez, M. J. Ruiz, P. Terreros and I. Cuadrado, Dalton Trans., 2018, 47, 15391 DOI: 10.1039/C8DT02641F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements