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Multistability on the molecular scale level required for molecular devices can be realized using metallocomplexes with redox-active ligands such as o-quinones, o-quinoneimines and o-diimines as building blocks. Herein, we prepared four sterically shielded di-o-quinones bridged with a dioxyarylene linker with different topology and steric characteristics and studied the properties of their reduced species. EPR spectroscopy investigation revealed that the intramolecular exchange interaction between paramagnetic centers in the biradical dianion derivatives of synthesized di-o-quinones predominantly depends on the steric environment of the linker and the nature of the counter cation at the dioxolene site, and the topology of the linker plays a secondary role. [ABSTRACT FROM AUTHOR]

[Display omitted] Reaction of 3-hydroxy-2,5-di- tert -butyl-1,4-benzoquinone with phenylhydrazine hydrochloride mainly leads to the corresponding hydrazone at the position 1 existing in tautomeric equilibrium with 3,6-di- tert -butyl-4-(phenyl- diazenyl)catechol. Thermodynamic parameters of the tautomerization were evaluated by NMR spectroscopy. The hydrazone structure was confirmed by XRD study. [ABSTRACT FROM AUTHOR]

Ditopic di-o-quinone with a resorcinol bridge exhibits the ability to self-assemble in a reaction with copper, giving a cage-like binuclear complex that, due to the cofacially placed metal ions, is capable of encapsulation of different solvent molecules as guest ligands. Notably, the geometry of the internal cavity of this complex adjusts depending on the coordinating properties of the encapsulated molecule (mono- or bidentate). A feature of this species is that the cage-forming units are copper(II) bis-semiquinonate moieties, capable of undergoing ligand-centered redox transformations. Electrochemical and EPR spectroscopy studies showed that there is a channel for intramolecular electronic exchange interactions between the redox centres of the molecule. [ABSTRACT FROM AUTHOR]

o-Quinones are both well-studied and promising redox-active chelating ligands. There are plenty of interesting effects to be found on o-quinone-derived metallocomplexes, such as photo-thermo mechanical effect in solid phase and in solution, luminescence, SMM properties and so on. A combination o-quinone function with an additional coordination site or redox active fragment in the same molecule might sufficiently extend an assembling as well as functional capability of such ligand in complexes. In this paper, the authors focus on o-quinones decorated with additional non-dioxolene chelating coordination site or with electron donor redox active annelated fragments. [ABSTRACT FROM AUTHOR]

Ditopic di- o -quinone with a resorcinol bridge exhibits the ability to self-assemble in a reaction with copper, giving a cage-like binuclear complex that, due to the cofacially placed metal ions, is capable of encapsulation of different solvent molecules as guest ligands. Notably, the geometry of the internal cavity of this complex adjusts depending on the coordinating properties of the encapsulated molecule (mono- or bidentate). A feature of this species is that the cage-forming units are copper(II) bis-semiquinonate moieties, capable of undergoing ligand-centered redox transformations. Electrochemical and EPR spectroscopy studies showed that there is a channel for intramolecular electronic exchange interactions between the redox centres of the molecule.