Ultrafast charge transfer and coherent oscillations in 4-piperidino- benzonitrile

T. Yatsuhashi, S. A. Trushin, W. Fuß, W. Rettig, W. E. Schmid, S. Zilberg

Research output: Contribution to journalArticlepeer-review

25 Scopus citations


The La-like S2 state of 4-(1-piperidino) -benzonitrile and the corresponding 3,5-dimethyl-piperidino derivative was excited at 270 nm in the gas phase at 130°C. Nonresonant multiphoton ionization at infrared wavelengths (810 and 1300 nm) with mass-selective detection of the ion yields then probed the subsequent processes. Two groups of time constants were found: in the range <2 ps and in the 100 ps range. In addition, a coherent oscillation with period 1.06 and 1.18 ps for the unsubstituted and substituted species were monitored until about 10 ps. The sub-picosecond time constants can be assigned to relaxation from S2 through a conical intersection to both S1 (Lb-like) and a charge transfer (CT) state. These two states then equilibrate within about 1.9 ps. The oscillation must be a vibration in Lb, because this is the only state still populated at 10 ps. It is suggested to assign it to the amino-group wagging (planarization/pyramidalization). It indicates a component of the direction into which the conical intersection is displaced from the Lb minimum. The ultrafast relaxation times suggest, however, that additional coordinates are involved in the process, probably amino-group twist and bond stretching in the benzene ring.

Original languageEnglish
Pages (from-to)1-12
Number of pages12
JournalChemical Physics
Issue number1
StatePublished - 5 Jan 2004
Externally publishedYes


Dive into the research topics of 'Ultrafast charge transfer and coherent oscillations in 4-piperidino- benzonitrile'. Together they form a unique fingerprint.

Cite this