The First Structural Characterization of an Azoaromatic Radical Anion Stabilized by Dicopper(I) Coordination

Re-evaluating the Cu K pre-edge XAS transition in complexes with covalent metal–ligand interactions

“…The N–N distance in the diazene portion of 3 , 1.352(2)/1.347 Å lies within experimental error of the 1.345(7) Å N–N bond distance in the monocationic, dinuclear Cu( i ) complex of azobis(5-chloropyrimidine)˙ 1– . 42 Again, these values are partway between those of the neutral diazene (1.250(3) Å, see ESI † ) and related diarylhydrazines (1.45–1.47 Å). 43 , 44…”

“…39,41 The N-N distance in the diazene portion of 3, 1.352(2)/1.347 Å lies within experimental error of the 1.345(7) Å N-N bond distance in the monocationic, dinuclear Cu(I) complex of azobis(5-chloropyrimidine)c 1À . 42 Again, these values are partway between those of the neutral diazene (1.250(3) Å, see ESI †) and related diarylhydrazines (1.45-1.47 Å). 43,44 For the styrene complexes 4 and [7 + ], the C-C bond distances within the h 2 -bound alkene (1.373(6)/1.398 Å for 4 and 1.395(6)/ 1.397 Å for [7 + ]) show only modest lengthening compared to a styrenyl C]C distance of ca.…”

Recent advances on the chemistry of transition metal complexes of 2-(arylazo)pyridines and its arylamino derivatives

“…The first reports on stable azo-anion radical complexes of the diamagnetic metal ions Ru(II) and Cu(I) appeared almost simultaneously. 22, 23 During recent years there has been considerable progress in this area that has unveiled many novel features of complexes of these redox-active azo ligands.…”

A supramolecular radical cation: folding-enhanced electrostatic effect for promoting radical-mediated oxidation

“…Supramolecular free radicals refers to radicals stabilized or activated by non-covalent interactions, 1 – 4 which hold potential in the fields of spin-based materials 5 – 12 and radical-mediated reactions. 13 – 19 Various non-covalent interactions can be employed to modulate the reactivity of radicals, including hydrogen bonding, 20 , 21 metal–ligand interactions, 22 , 23 charge-transfer interactions, 24 , 25 and host–guest interactions. 26 – 29 Benefiting from the dynamic and reversible nature of non-covalent interactions, these supramolecular methods have distinctive advantages in many aspects, such as avoidance of tedious covalent synthesis, switchable properties and potential in constructing adaptive radical systems.…”