Hole- and Electron-Vibrational Couplings in Oligoacene Crystals: Intramolecular Contributions

The hole-vibrational coupling is reported for anthracene, tetracene, and pentacene on the basis of a joint experimental and theoretical study of ionization spectra using high-resolution gas-phase photoelectron spectroscopy and first-principles correlated quantum-mechanical calculations. The hole-vibrational coupling is found to be significantly smaller than the electron-vibrational coupling in the case of these oligomers; however, both quantities are predicted to converge to the same value when increasing the chain length.

Figure 1

Gas-phase He I UPS spectra of anthracene (A), tetracene (B), and pentacene (C).

Figure 2

High resolution closeups of the first ionizations of anthracene (A), tetracene (B), and pentacene (C). The Gaussians used for the deconvolution are shown with a thick solid line. The thin solid lines represent the overall fit, while the dots correspond to the experimental data.

Figure 3

Hole-vibrational coupling [◆-Exp, ○-B3LYP(AP)] and electron-vibrational coupling [□-B3LYP(AP)] vs the inverse of the number of carbon atoms in anthracene, tetracene, and pentacene.