Coordination Chemistry of a π-Extended, Rigid and Redox-Active Tetrathiafulvalene-Fused Schiff-Base Ligand

Abstract

A pi-extended, redox-active tetradentate tetrathiafulvalene-fused salphen [salphen = N,N'-phenylenebis(salicylideneimine)] compound (L) was prepared via a direct Schiff-base condensation of the corresponding diamine-tetrathiafulvalene (TTF) precursor with salicylaldehyde. Its chelating coordination ability has been demonstrated by the formation of the corresponding transition metal complexes in the presence of M(OAc)2.nH2O (M = Co(II), Ni(II), Cu(II)) and FeCl3.6H2O. Three complexes have been characterized by single-crystal X-ray diffraction analysis showing that the TTF-salphen ligand coordinates to the metal ions in a planar mode through the nitrogen and oxygen atoms in a N2O2 cis-configuration. In the case of Fe(III), a dinuclear oxo-bridged Fe(III) complex is formed. These paramagnetic complexes are promising building blocks for the construction of dual functional materials due to their unique structural features (planarity and rigidity) as well as their inherent redox properties.

Tetrathiafulvalene-based group XV ligands: Synthesis, coordination chemistry and radical cation salts

“…Accordingly, a TTF-salphen ligand 97 was synthesized via the condensation reaction of salicylaldehyde with a TTF diamine precursor (Scheme 30). Deprotonation of the phenol functions of TTF 97 provides a tetradentate N 2 O 2 coordination sphere for metal ions [81]. TTF-salphen ligand 97 undergoes two well-separated quasi reversible one-electron oxidation processes at E 1 1/2 = 0.60 V and in CH 2 Cl 2 vs. Ag/AgCl.…”

“…The complex Fe2, reported by Liu and co-workers [81], consists of two TTF-salphen (97) Fe III units interconnected in axial positions by a -oxo bridge. Its synthesis involved the reaction of the TTF-bis(imine) with FeCl 3 ·6H 2 O in the presence of triethylamine.…”

Synthesis and Properties of two CuI Complexes Involving Tetrathia-fulvalene-Fused Phenanthroline Ligand

“…Compared with L 1 -L 2 , the absorption bands at low energy (λ > 350 nm) of complexes 1-2 are slightly blue shifted, and the intensities are increased around 400-410 nm, which may be related to metalation of the ligand. 15 …”

Electroactive Bisiminopyridine Ligands: Synthesis and Complexation Studies

“…In order to address this challenge, considerable effort has been devoted in associating the TTF moiety with an inorganic component and various organic mono-or polydentate ligands, and their corresponding electroactive metal complexes have therefore been reported [6]. For example, metal complexes of phosphines [7][8][9][10][11][12], dithiolates [13], acetylacetonates [14], pyridines [15][16][17], bipyridines [18,19] and more recently of Schiff bases [20][21][22] have been synthesized. Pyridine based Schiff bases ligands such as 2,6-bis(imino)pyridyl, with chelating abilities, form stable complexes, with various transition metals, which have been extensively used as catalysts for olefin polymerization [23,24].…”