Complexes of diamagnetic cations with radical anion ligands

Abstract

The review summarizes and analyzes the currently know data on the synthesis, molecular and electronic structures and magnetic properties of bi-, tri- and tetraradical complexes containing a diamagnetic metal ion and redox-active ligands in the paramagnetic form. The bibliography includes 193 references.

Supramolecular D⋯A-layered structures based on germanium complexes with 2,3-dihydroxynaphthalene and N,N′-bidentate ligands

“…The use of redox-active ligands is an effective approach to control and regulate the electrochemical, photochemical and magnetic properties of organometallic compounds, to manipulate their reactivity in chemical processes. [1][2][3][4][5] In this regard, the concept of redox-active ligands has found various applications in the production of new materials with useful properties 6 and catalysis 7,8 as well as chemistry of organogermanium derivatives 9-12 etc. Germanium is a "special" element of the Periodic Table . Its chemical properties are similar to ones of the ancestor of the 14th groupcarbonthe basic element of organic chemistry.…”

Structural Changes in Five‐Coordinate Bromido‐bis(o‐iminobenzo‐semiquinonato)iron(III) Complex: Spin‐Crossover or Ligand‐Metal Antiferromagnetic Interactions?

“…[16,17] Moreover, o-benzoquinone and o-iminobenzoquinone complexes were found to demonstrate a spin-crossover effect [18][19][20][21][22][23] and different types of inter-or intramolecular magnetic exchange interactions. [18][19][20][21]24,25] The application of radical-ionic ligands as spin labels in metal complexes allows one to examine their composition, structure and dynamic processes by means of electron paramagnetic resonance spectroscopy. [26][27][28] On the other hand, redox ligands can be used as reservoirs of electrons for bond-making and bond-breaking reactions.…”

“…Detailed investigation of magnetic properties, electrochemical and spectroscopic features allowed ones to discover such unique phenomena as redox‐isomerism (or valence‐tautomerism), [3,8–15] photo and termomechanical effects [16,17] . Moreover, o‐benzoquinone and o‐iminobenzoquinone complexes were found to demonstrate a spin‐crossover effect [18–23] and different types of inter‐ or intramolecular magnetic exchange interactions [18–21,24,25] . The application of radical‐ionic ligands as spin labels in metal complexes allows one to examine their composition, structure and dynamic processes by means of electron paramagnetic resonance spectroscopy [26–28] …”

Dithiolate and Catecholate Binding of Copper by the OO∼SS Bifunctional Ligand: Regioselectivity and Regioisomeric Transformations

“…This redox interconversion can be switched by various external stimuli such as solvent polarity, thermal or optical changes, as well as it can be driven by addition/abstraction of an auxiliary ligand. [5] Recently we reported the coordination properties of the oquinone annulated with dithiete cycle 1. [6][7][8][9] Functionalization of the o-quinone molecule with an additional chelating coordination site converted it into bridging ligand possessing a rigid and almost planar structure.…”