Hydrocarbon ions with triplet ground states

Half-Sandwich Complexes of an Extremely Electron-Donating, Redox-Active η6-Diborabenzene Ligand

“…The only stable benzene-derived dianions known are highly conjugated [42][43] or sterically and electronically stabilized by multiple bulky silyl groups; [44][45][46] in the case of 1, the ability of the CAAC moieties to accept π-electron density from the ring leads to the stability of the highly reduced species 6.…”

Counter-ion effects on the spin density distribution in triplet aromatic dianions

“…[1] demonstrated that alkali metal counter ions may strongly perturb the spin distribution. Here we report results which prove that similar polarizing effects influence the triplet dianions of 1,3,5-triphenylbenzene (Tpb) and decacyclene (Dec) [2].…”

“…The intermediate spectra then must be assigned to a dianion coordinated with one counter-ion or, alternatively, a dianion with one counter-ion in the first coordination sphere and the other in the second coordination sphere. It is of interest that, in contrast to the dianion of Tp, the perturbation of the spin distribution in Tpb = and Dec = [2] does not induce a loss of symmetry under 'normal' conditions (solvent MTHF, temperature -160~ Therefore, the counter-ions must be located either on the threefold axis or must jump rapidly around the molecule, on the average preserving trigonal symmetry. In the latter case one expects that at a very low temperature the rate of this dynamic process will Downloaded by ["Queen's University Libraries, Kingston"] at 22:59 04 January 2015 ).…”

Electron Paramagnetic Resonance in the Netherlands

“…For such anions an electron spin triplet (S=l) was predicted in a simple Hiickel molecular orbital approach. For triphenylbenzene dianions and decacyclene dianions the triplet spin nature of the ground state could indeed be verified by means of EPR (9). The spin multiplicity of the coronene dianion remained a puzzling problem, however.…”