Dajun J. Ding

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We study the formation of plasmon modes of small gold clusters by modeling the excitation spectra. The shape change of the longitudinal mode as a function of cluster size is studied using time-dependent Kohn-Sham theory and Gaussian basis sets. The presence of d electrons in gold atoms affect the plasmon formation process, resulting in a high excitation(More)
The adsorption of six free radicals (FRs) respectively on a graphene fragment was studied using a density functional tight-binding method with the inclusion of an empirical dispersion term in total energy. The results indicate that the different interaction paths between the FRs and the graphene lead to different forms of physical (PA) or chemical(More)
Excited-state double proton transfer (ESDPT) in the hydrogen-bonded 2-(1H-pyrazol-5-yl)pyridine with propyl alcoholic partner (PPP) was theoretically investigated by time-dependent density functional theory (TDDFT) method. Great changes have taken place for the calculated geometric structures, the electron density features and vibrational spectrum of PPP(More)
The excited-state intramolecular charge transfer (ICT) of LD 490 were investigated in different hydrogen-bond-donating solvents (α scale) on the basis of the Kamlet-Taft solvatochromic parameters (π*, α, β). The femtosecond transient absorption spectra and the kinetics decay rate reveal that with an increase of solvent's α capacity, the long-lived(More)
Two molecules, 1-hydroxypyrene-2-carbaldehyde (HP) and 1-methoxypyrene-2-carbaldehyde (MP) were explored. We investigated their photophysical properties, using experimental transient absorption and theoretical density functional theory/time-dependent density functional theory (DFT/TDDFT). HP and MP have similar geometric conformations but exhibit entirely(More)
  • Yuta Ito, Chuncheng Wang, +4 authors Kiyoshi Ueda
  • Structural dynamics
  • 2016
We have measured the angular distributions of high energy photoelectrons of benzene molecules generated by intense infrared femtosecond laser pulses. These electrons arise from the elastic collisions between the benzene ions with the previously tunnel-ionized electrons that have been driven back by the laser field. Theory shows that laser-free elastic(More)
To promote possible applications of graphene in molecular identification based on stacking effects, in particular in recognizing aromatic amino acids and even sequencing nucleobases in life sciences, we comprehensively study the interaction between graphene segments and different cyclic organic hydrocarbons including benzene (C6H6), cyclohexane (C6H12),(More)
A modified quasi-quantum treatment (MQQT) of molecular scattering has been developed to account for the softness of the repulsive part of the anisotropic atom-molecule PES. A contour of the PES is chosen such that the barrier height is just large enough to reflect the incoming kinetic energy, directed anti-parallel to the hard shell normal at the site of(More)
The ionization/dissociation mechanism of cyclopentanone has been experimentally investigated in molecular beam by irradiating with intense 394 and 788 nm laser fields with pulse duration of 90 fs. The range of laser intensities varied from 3 x 10(13) to 4 x 10(14) W/cm(2). For both wavelengths, the singly charged parent ion is observable while the doubly(More)
Ultrafast carrier relaxation dynamics in fluorescent carbon nanodots is investigated by femtosecond transient absorption spectra at different pH environments so as to understand the mechanism of fluorescence for the first time. Utilizing multi-wavelength global analysis to fit the measured signal via a sequential model, four different relaxation channels(More)