Syntheses, structures and properties of structurally characterised complexes of imide-based ligands

Switching and redox isomerism in first-row transition metal complexes containing redox active Schiff base ligands

The reversible redox isomerisms in first row transition metal complexes of the type ML2 were studied. The six ML2 complexes (M = Mn(III) (), Fe(II) (), Co(III) (), Ni(II) (), Cu(II) () and Zn(II) ()) were synthesized with a redox active Schiff base ligand [2-(3,5-di-tert-butyl-2-hydroxyphenylamino)-4-chlorophenol] (H3L) presenting different oxidation states from -2 to 0 (L(2-), L(-) and L(0)). EPR spectra and magnetic susceptibility measurements indicate the presence of complexes of the type [Mn(III)(L(2-))(L(-))] () with S = 1/2, [Fe(II)(L(-))2] () with S = 2, [Co(III)(L(2-))(L(-))] () with S = 1/2, [Ni(II)(L(-))2] () with S = 1, [Cu(II)(L(-))2] () with S = 1/2 and [Zn(II)(L(-))2] () with S = 0 at high temperatures. Temperature and solvents influence the electronic structures of the species and give several valence tautomers. At low temperatures these complexes present thermally induced metal-to-ligand (, , ) or ligand-to-ligand (in , ) electron transfer (partial or total), resulting in compounds of the type [Mn(IV)(L(2-))2] () with S = 1/2, [Fe(III)(L(-))(L(2-))] () with S = 1, [Ni(III)(L(2-))(L(-))] () with S = 0, [Cu(II)(L(2-))(L(0))] () with S = 1/2 and [Zn(II)(L(2-))(L(0))] () with S = 1. This electron transfer is in agreement with the general trend in the redox potentials of the first row transition metal ions from Mn(ii) to Zn(ii), and it allows us to prepare and stabilize reversibly switchable tautomeric forms in transition metal complexes with redox-active ligands.

Pyrazine-imide complexes: reversible redox and MOF building blocks

Stepwise exchange of pyrazine for pyridine, in three bis-heterocycle-based imide ligands, tunes the potential of the [M^II/III(ligand)₂]^0/+ redox couple, increasing the stability of the M^II oxidation state by about 0.1 V per exchange.

A cyclic tetranuclear cuboid type copper(ii) complex doubly supported by cyclohexane-1,4-dicarboxylate: molecular and supramolecular structure and cyclohexane oxidation activity

A rare isolated tetranuclear 3d complex with a single metal CDC cuboid cage. It catalyzes cyclohexane peroxidative oxidation without any promoter.

Fluorophore incorporation allows nanomolar guest sensing and white-light emission in M4L6 cage complexes

M₄L₆ cages built from BODIPY- and pyrene-containing subcomponents perform multiple functions: sensing anions and amino acids, and forming a white-light emitting complex with perylene.