Excited-state vibrational coherence of solution-phase polyatomic molecules was studied by two different timedomain spectroscopic methods. Raman-active low-frequency vibrations in the excited state of trans-stilbene were observed by transient impulsive stimulated Raman scattering spectroscopy. In transient absorption spectroscopy with a 40-fs resolution, a different vibrational mode of the same ...

Low-temperature transport spectroscopy measurements on a suspended few-hole carbon nanotube quantum dot are presented, showing a gate-dependent harmonic excitation spectrum which, strikingly, occurs in the Coulomb-blockade regime. The quantized excitation energy corresponds to the scale expected for longitudinal vibrations of the nanotube. The electronic transport processes are identified as co...

We combined femtosecond (fs) VIS pump-IR probe spectroscopy with fs VIS pump-supercontinuum probe spectroscopy to characterize the photoreaction of the hexacoordinated Al(tpfc-Br8)(py)2 in a comprehensive way. Upon fs excitation at ∼400 nm in the Soret band, the excitation energy relaxes with a time constant of (250 ± 80) fs to the S2 and S1 electronic excited states. This is evident from the r...

Over the last few decades, infrared (IR) spectroscopy has been recognized as a useful tool to obtain quantitative and qualitative information on IR active materials and bio-materials, with particular emphasis to polymer chemistry and organic chemistry. Nowadays, thanks to technological evolution, the possibilities offered by vibrational spectroscopy (e.g. IR and Raman spectroscopy) are much bro...

The absolute configuration and solution-state conformers of three peperomin-type secolignans isolated from Peperomia blanda (Piperaceae) are unambiguously determined by using vibrational circular dichroism (VCD) spectroscopy associated with density functional theory (DFT) calculations. Advantages of VCD over the electronic form of CD for the analysis of diastereomers are also discussed. This wo...

Two Pt-H vibrational bands at 1679 cm(-1) and 1392 cm(-1) observed with 13-atom Pt clusters supported in LTL zeolite by Fourier Transform Infrared (FTIR) spectroscopy confirms that H atoms bridge two Pt atoms across the edges of the metal cluster. An additional broad absorption band centred near 2200 cm(-1) which exhibits some substructure is assigned to low energy electronic excitations across...

© 2007 American Institute of Physics, S-0031-9228-0711-020-6 When light interacts with matter, it can scatter inelastically from vibrational quantum states. During that process, photons may lose energy to, or gain it from, vibrational excitations. A change in the photon energy must produce a concomitant shift in the frequency of the scattered light (see box 1). The phenomenon, called the Raman ...

We have introduced a computational methodology to study vibrational spectroscopy in clusters inclusive of critical nuclear quantum effects. This approach is based on the recently developed quantum wavepacket ab initio molecular dynamics method that combines quantum wavepacket dynamics with ab initio molecular dynamics. The computational efficiency of the dynamical procedure is drastically impro...