As a new precursor for a hydrogen-bonded open-shell system, we have designed and synthesized 2,5,8-tri- tert -butyl-4,9-dihydroxyphenalenone 1 from commercially available 2,7-dimethoxynaphthalene in nine steps. The neutral radical generated from 1 with active PbO 2 exhibits higher stability compared with other 6-oxophenalenoxyl derivatives in the solid state. From the results of ESR and ENDOR/TRIPLE
New Stable Neutral Radical with Intramolecular Hydrogen Bonding: Synthesis and Characterization of 2,5,8-Tri-<i>tert</i>-butyl-7-hydroxy-6-oxophenalenoxyl
A new stable neutralradical with intramolecular hydrogen bonding, 2,5,8-tri-tert-butyl-7-hydroxy-6-oxophenalenoxyl, was synthesized from the corresponding dihydroxyphenalenone and isolated as a stable solid under air atmosphere at room temperature. The structure was unequivocally determined by means of IR spectra, ESR/ENDOR techniques, and DFT calculations.
Redox-Based Spin Diversity in a 6-Oxophenalenoxyl System: Generation, ESR/ENDOR/TRIPLE, and Theoretical Studies of 2,5,8-Tri-<i>tert</i>-butylphenalenyl- 1,6-bis(olate) Salts
[GRAPHIC]Novel open-shell molecular salts, 2,5,8-tri-tert-butylphenalenyl-1,6-bis(olate) salts, were designed on the basis of the 6-oxophenalenoxyl system and generated by the chemical reduction of 6-hydroxyphenalenone derivatives. ESR/ENDOR/TRIPLE measurements and DFT calculations provide unequivocal determination of the structure and spin density distribution, which demonstrate redox-based spin diversity of the 6-oxophenalenoxyl system.