Valence Electronic Structure and Charge Transfer in Tetrathiofulvalinium Tetracyanoquinodimethane (TTF-TCNQ) from Photoemission Spectroscopy

Abstract

Comparison of ultraviolet-photoemission, valence-orbital spectra (as well as high-resolution, x-ray photoemission, N-core-level spectra) of TTF-TCNQ, neutral TCNQ, and ${\mathrm{K}}^{+}$ ${\mathrm{}\left(\mathrm{TCNQ}\right)\mathrm{}}^{-}$ indicates a large amount of charge transfer in TTF-TCNQ. The spectra for this complex show strong coupling between states near the Fermi energy and molecular vibrations due to localization of the mobile electrons on individual molecules, at least on the time scale of bond vibrations. DOI: http://dx.doi.org/10.1103/PhysRevLett.32.534 © 1974 The American Physical Society