Polarographic and electron paramagnetic resonance study of one electron reduction of alkylated benzoquinones

Platinum(ii) complexes of mixed-valent radicals derived from cyclotricatechylene, a macrocyclic tris-dioxolene

“…This must be due to H 4, because the C 4,5 positions carry much greater spin density than C 3,6. 47 The maximum splitting observed is ca. 15 MHz at 1192 mT, that is, in the molecular xy plane.…”

“…The g ≈ 2.002 value and hyperfine analysis (see below) for both radicals identify the singly occupied molecular orbital (SOMO) as largely localised in the dioxolene ligand π-system, but with some contribution from metal-based orbitals. The strongly coupled proton is assigned to H 4 of the [DBsq˙] – ligand (HDBsq = 3,5-di( tert -butyl)-1,2-benzosemiquinone), 47 since the C 4,5 positions carry much greater spin density than C 3,6 (see below).…”

“…58 The accuracy of these DFT calculations was calibrated by comparison with experimental literature data from [DBsq˙] – . 47 …”

“…The isotropic H4 and H6 values of hai ¼ 9.4 and 1.8 MHz are a close match for those of [DBsqc] À itself in uid solution (9.5 and 1.8 MHz). 47 These parameters imply the spin density at C4,5 is ca. ve times that at C3,6.…”

Transition Metal Complexes and Radical Anion Salts of 1,10-Phenanthroline Derivatives Annulated with a 1,2,5-Tiadiazole and 1,2,5-Tiadiazole 1,1-Dioxide Moiety: Multidimensional Crystal Structures and Various Magnetic Properties

“…Figure 14 shows the CV of tdapO 2 , which indicates two reversible reduction peaks at –0.520 and –1.32 V vs. Fc + /Fc; these processes suggest that the mono and dianionic species of tdapO 2 are stable and the acceptor ability of tdapO 2 are comparable to those of the halogen-substituted p -benzoquinones [61,62,63,64]. It is notable that the related compound tdap exhibits very weak acceptor ability (see Figure 1).…”