70782-26-2Relevant academic research and scientific papers
A facile and versatile approach to double N-heterohelicenes: Tandem oxidative C-N couplings of N-heteroacenes via cruciform Dimers
Sakamaki, Daisuke,Kumano, Daisuke,Yashima, Eiji,Seki, Shu
, p. 5404 - 5407 (2015)
Novel double N-hetero[5]helicenes that are composed of two nitrogen-substituted heteropentacenes are synthesized by tandem oxidative C-N couplings via the cruciform heteropentacene dimers. The developed method is very facile and enables the synthesis of a double helicene in only two steps from commercially available naphthalene derivatives. These double N-hetero[5]helicenes have larger torsion angles in the fjord regions than typical [5]helicenes, and optical/electrochemical measurements revealed a significant increase in the electronic communication between the two heteropentacene moieties of the double helicenes compared with their cruciform dimers. The optical resolution of one of the double helicenes was successfully carried out, and their stability towards racemization was remarkably higher than those of typical [5]helicenes. The synthetic strategy proposed in this paper should be versatile and widely applicable to the preparation of double helicenes from other N-containing π-conjugated planar molecules.
Chemiluminescence of Dimethyldioxetanone. Unimolecular Generation of Excited Singlet and Triplet Acetone. Chemically Initiated Electron-Exchange Luminescence, the Primary Light Generating Reaction
Schmidt, Steven P.,Schuster, Gary B.
, p. 306 - 314 (2007/10/02)
Dimethyldioxetanone (2a) undergoes two distinct thermal reactions which generate electronically excited states.The unimolecular decomposition of 2a at 30.0 deg C produces excited singlet and triplet acetone, with efficiencies of 0.1 and 1.5percent, respectively.The composite activation energy for formation of singlet acetone is 3-4 kcal mol-1 greater than the activation energy for the thermal disappearance of 2a.This result is interpreted in terms of two parallel competitive pathways for dioxetanone decomposition, the more highly activated one of which leads to excited acetone.The addition of easily oxidized aromatic hydrocarbons or amines catalyzes the chemiluminescence of 2a.The magnitude of the catalytic rate constant and the efficiency of light production are correlated with the one electron oxidation potential of the hydrocarbon.Under these conditions, the chemiluminescence results from a chemically initiated electron-exchange luminescence path.
