Help Privacy Policy Disclaimer
  Advanced SearchBrowse




Journal Article

Formation of an intermolecular charge-transfer compound in UHV codeposited tetramethoxypyrene and tetracyanoquinodimethane

There are no MPG-Authors in the publication available
External Resource
No external resources are shared
Fulltext (restricted access)
There are currently no full texts shared for your IP range.
Fulltext (public)
There are no public fulltexts stored in PuRe
Supplementary Material (public)
There is no public supplementary material available

Medjanik, K., Perkert, S., Naghavi, S., Rudloff, M., Solovyeva, V., Chercka, D., et al. (2010). Formation of an intermolecular charge-transfer compound in UHV codeposited tetramethoxypyrene and tetracyanoquinodimethane. Physical Review B, 82(24): 245419, pp. 1-9. doi:10.1103/PhysRevB.82.245419.

Cite as: https://hdl.handle.net/11858/00-001M-0000-0018-B6A4-B
Ultrahigh vacuum (UHV)-deposited films of the mixed phase of tetramethoxypyrene and tetracyanoquinodimethane (TMP(1)-TCNQ(1)) on gold have been studied using ultraviolet photoelectron spectroscopy (UPS), x-ray diffraction (XRD), infrared (IR) spectroscopy, and scanning tunneling spectroscopy (STS). The formation of an intermolecular charge-transfer (CT) compound is evident from the appearance of new reflexes in XRD (d(1)=0.894 nm and d(2)=0.677 nm). A softening of the CN stretching vibration (redshift by 7 cm(-1)) of TCNQ is visible in the IR spectra, being indicative of a CT on the order of 0.3e from TMP to TCNQ in the complex. Characteristic shifts in the electronic level positions occur in UPS and STS that are in reasonable agreement with the prediction of density-functional theory (DFT) calculations (GAUSSIAN03 with hybrid functional B3LYP). STS reveals a highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap of the CT complex of about 1.25 eV being much smaller than the gaps (>3.0 eV) of the pure moieties. The electron-injection and hole-injection barriers are 0.3 eV and 0.5 eV, respectively. Systematic differences in the positions of the HOMOs determined by UPS and STS are discussed in terms of the different information content of the two methods.