Diimide

Abstract: The radical anions of aromatic diimides have been implicated recently in a wide variety of photochemical electron transfer reactions. Photoexcitation of these radical anions produces powerfully reducing species. Yet, the properties of the π* excited doublet states of these organic radical anions remain obscure. The radical anions of three aromatic imides with increasingly larger π systems, N-(2,5-di-tert-butylphenyl)phthalimide, 1, N-(2,5-di-tert-butylphenyl)-1,8-naphthalimide, 2, and N-(2,5-di-tert-butylphenyl)perylene-3,4-dicarboximide, 3, as well as the three corresponding aromatic diimides, N,N‘-bis(2,5-di-tert-butylphenyl)pyromellitimide, 4a, N,N‘-bis(2,5-di-tert-butylphenyl)-naphthalene-1,8:4,5-tetracarboxydiimide, 5a, and N,N‘-bis(2,5-di-tert-butylphenyl)perylene-3,4:9,10-tetracarboxydiimide, 6, were produced by electrochemical reduction of the neutral molecules in an optically transparent thin layer electrochemical cell. The radical anions of these imides and diimides all exhibit intense visible a...

Abstract: Design of green, safe, and sustainable process for the synthesis of hydrogen peroxide (H2O2) is a very important subject. Early reported processes, however, require hydrogen (H2) and palladium-based catalysts. Herein we propose a photocatalytic process for H2O2 synthesis driven by metal-free catalysts with earth-abundant water and molecular oxygen (O2) as resources under sunlight irradiation (λ>400 nm). We use graphitic carbon nitride (g-C3N4) containing electron-deficient aromatic diimide units as catalysts. Incorporating the diimide units positively shifts the valence-band potential of the catalysts, while maintaining sufficient conduction-band potential for O2 reduction. Visible light irradiation of the catalysts in pure water with O2 successfully produces H2O2 by oxidation of water by the photoformed valence-band holes and selective two-electron reduction of O2 by the conduction band electrons.

Abstract: N,N′-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C8H) thin films have been implemented into organic thin-film field-effect transistors Mobilities up to 06 cm2 V−1 s−1 and current on/off ratios >105 were obtained Linear regime mobilities were typically half of those measured in the saturation regime X-ray studies in reflection mode suggest a spacing of ∼20 A for thin evaporated films of PTCDI-C8H, which is consistent with the value of ∼21±2 A obtained from our simulations when an interdigitated packing structure is assumed

Abstract: The electrochemistry, UV−vis spectrophotometry, photoluminescence, and electrogenerated chemiluminescence (ECL) of perylenedicarboxylic imide, perylenetetracarboxylic diimide (PDI), terrylenetetracarboxylic diimide (TDI), and quaterrylenecarboxylic diimide (QDI) were investigated. All compounds undergo two reversible one-electron reductions and one reversible one-electron oxidation reaction. The first reduction potential shifts to less negative values and the potential for oxidation to less positive values for the diimide series with increasing size of the aromatic core. These changes in potential correlate well with orbital energies from molecular orbital calculations. The difference in potential between the first and second reduction waves decreased with increasing distance between the imide groups, so that TDI and QDI show only a single reduction wave, equivalent to a two-electron reduction. These reduction potentials provide estimates for the equilibrium constant for disproportionation of the radical ...