Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study

Details Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study

2010-12-15

arxiv.org/abs/1012.3467v1

Physics

Condensed Matter

Materials Science

13 pages, 5 figures

Scientific paper

It is demonstrated that the near-edge X-ray absorption fine structure (NEXAFS) provides a powerful local probe of functional groups in novel charge transfer (CT) compounds. Microcrystals of tetra- and hexamethoxypyrene as donors with the strong acceptor tetracyanoquinodimethane (TMPx/HMPx - TCNQy) were grown from solution via vapour diffusion in different stoichiometries x:y = 1:1, 1:2 and 2:1. Owing to the element specificity of NEXAFS, the oxygen and nitrogen K-edge spectra are direct spectroscopic fingerprints of the donating and accepting moieties. The orbital selectivity of the NEXAFS resonances allows to precisely elucidate the participation of specific orbitals in the charge-transfer process. In the present case charge is transferred from methoxy-orbitals 2e (PI*) and 6a1 (SIGMA*) to the cyano-orbitals b3g and au (PI*) and - to a weaker extent - to b1g and b2u (SIGMA*). The occupation of 2e reflects the anionic character of the methoxy groups. Surprisingly, the charge transfer increases with increasing HMP content of the complex. As additional indirect signature, all spectral features of the donor and acceptor are shifted to higher and lower photon energies, respectively. Providing quantitative access to the relative occupation of specific orbitals, the approach constitutes the most direct probe of the charge-transfer mechanism in organic salts found so far. Although demonstrated for the specific example of pyrene-derived donors with the classical acceptor TCNQ, the method is very versatile and can serve as routine probe for novel CT-complexes on the basis of functionalized polycyclic aromatic hydrocarbons.

Affiliated with

Also associated with

No associations

Rating

Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Orbital-Resolved Partial Charge Transfer from the Methoxy Groups of Substituted Pyrenes in Complexes with Tetracyanoquinodimethane - a NEXAFS Study will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-218127