Dynamic nuclear polarization with photo-excited triplet electrons using 6,13-diphenylpentacene
Abstract
Dynamic nuclear polarization with photo-excited triplet electrons (Triplet-DNP) is demonstrated using 6,13-diphenylpentacene (DPPentacene). DPPentacene is soluble in various organic solvents, while pentacene, which is used in most of the triplet-DNP experiments, has limited solubility. An enhancement factor of 81 is obtained for 1H spins in the glass of ethanol-d6 : water = 80 : 20 (w/w) doped with 0.1 mM DPPentacene at 90 K in 0.67 T.