Volume 121, Issue 23, 15 December 2004
Index of content:
121(2004); http://dx.doi.org/10.1063/1.1834566View Description Hide Description
Predissociationspectra of the cluster ions are reported in the 1000–1900 cm−1 region. The weakly bound argon atoms enable investigation of the complex in a linear action mode, and the resulting spectra are much simpler than those reported previously in this region [Asmis et al., Science 299, 1375 (2003) and Fridgen et al., J. Phys. Chem. A 108, 9008 (2004)], which were obtained using infrared multiphoton dissociation of the bare complex. The observed spectrum consists of two relatively narrow bands at 1080 and 1770 cm−1 that are likely due to excitation of the shared proton and intramolecular bending vibrations of the two water molecules, respectively. The narrow linewidths and relatively small (60 cm−1) perturbation introduced by the addition of a second argon atom indicate that the basic “zundel” character of the ion survives upon complexation.
121(2004); http://dx.doi.org/10.1063/1.1835265View Description Hide Description
Four vibronic bands of the electronic transition of have been observed in the near infrared from using a highly sensitive spectrometer based on a Ti:sapphire laser and a positive column plasma. The two states are derived from the lowest state of the linear conformation as a result of a strong Renner–Teller effect. As expected, the rovibronic structure of the spectrum is very similar to that of the isoelectronic radical reported by Herzberg and Johns. Results of a preliminary analysis are given in which the rotational structures of the two states are treated independently, the ground state as a near-prolate asymmetric rotor and the excited state as a linear molecule.
Real-time detection of doorway states in the intramolecular vibrational energy redistribution of the OH/OD stretch vibration of phenol121(2004); http://dx.doi.org/10.1063/1.1829634View Description Hide Description
A picosecond time-resolved IR-UV pump–probe spectroscopic study was carried out for the intramolecular vibrational energy redistribution of the OH/OD stretching vibration of isolated phenol and its isotopomers in supersonic beams. The time evolution due to IVR showed a significant isotope effect; the OH stretch vibration showed a single exponential decay and its lifetime is greatly lengthened upon the deuterium substitution of the CH group. The OD stretch vibration exhibited prominent quantum beats. Especially, in phenol- the electronic transitions from the doorway states were clearly observed. They exhibited an out-of-phase quantum beat with respect to that of the OD stretch level and disappeared due to further IVR to the dense bath states. The transient spectra as well as the time evolution clearly evidenced the tier-model of the description of intramolecular vibrational energy redistribution.