The radical ions of hexacene

Stable photoinduced charge separation in heptacene

“…As expected, the observed NIR features of heptacene radical anion are red shifted compared to those in hexacene anion. 14 In summary, we confirm that the photobisdecarbonylation of 2 is a suitable approach toward heptacene 1 and that this reaction proceeds without any detectable intermediates even at temperatures as low as 10 K. The observed photoinitiated charge transfer of heptacene in an Ar matrix suggests that the higher acenes might be interesting for photoelectronic applications.…”

“…The g factors of the two radical ions were determined to be 2.0028, similar to those reported for the hexacene radical ions (2.0026 ¡ 0.0001). 14 (iv) Doping the matrix with 1.5% dichloromethane, an excellent electron trap, 15 suppresses the set of signals ascribable to the radical anion and results in a significantly increased yield of the radical cation of 1. The latter shows prominent transitions at 480 nm, 971 nm, 1060 nm, 1248 nm, and a weak low-energy band at 2134 nm in agreement with theory (see ESI{).…”

Electronic Absorption Spectra of Planar, Conjugated Biradicals in the Lowest Triplet State

“…To test the reliability of our model, we have performed calculations for more than sixty aromatic hydrocarbons. The results agree fairly well with the experimental data [16] [17], i.e. the transition energies are on the average overestimated by 5-lo%, but it must be realized that such a comparison is somewhat arbitrary, since in most cases only the positions and approximate intensities of the strongest triplet absorption bands are known experimentally.…”

Beyond Pentacenes: Synthesis and Properties of Higher Acenes

“…It was studied for crystalline material by Preuss and Zander [19], in solution by Wirz and co-workers [20] and Nijegorodov et al [21], and in a solid argon matrix by Bettinger et al [22]. The Wirz group also obtained solution spectra of the hexacene dication and dianion [20], as well as of its radical ions in the early 1980s [23]. The latter were also studied under matrix isolation conditions in solid argon [22].…”