Two dimensional electronic spectroscopy has proved to be a valuable experimental technique to reveal electronic excitation dynamics in photosynthetic pigment-protein complexes, nanoscale semiconductors, organic photovoltaic materials, and many other types of systems. It does not, however, provide direct information concerning the spatial structure and dynamics of excitons. 2D infrared spectrosc...

The structural configuration of molecules assembled at organic-inorganic interfaces within electronic materials strongly influences the functional electronic and vibrational properties relevant to applications ranging from energy storage to photovoltaics. Controlling and characterizing the structural state of an interface and its evolution under external stimuli is crucial both for the fundamen...

Electronic structure calculations, with a triple zeta plus polarization basis set and second-order perturbation theory, are used to predict the molecular and electronic structures for TiH3X compounds, with X = CH3, NH2, OH, SiH3, PHz, and SH. It is found that for the second-period substituents CH3, NHz, and OH the structures are similar to those of the corresponding silicon compounds. On the ot...

The optical spectra of nine dinitroaromatic radical anions (1,2- and 1,4-dinitrobenzene, 1,5- and 2,6-dinitro naphthalene, 4,4'-dinitrobiphenyl, 2,7-dinitro-9,9-dimethylfluorene, 2,6-dinitroanthracene, and 2,7- and 1,8-dinitrobiphenylene) in dimethylformamide are reported and analyzed. All have delocalized charge distribution, as demonstrated by the vibrational fine structure that is observed i...

The transition rule governing the inelastic excitations of molecular vibrations occurring during a molecular through-state electron transfer process is presented. Using an effective Hamiltonian model, it is shown that the quantum time oscillation of the intermediate electronic state population triggers this transition. Its corresponding quantum oscillation frequency has to be equal to a quantum...

We combine ultrafast optical spectroscopy with femtosecond X-ray absorption to study the photo-switching dynamics of the [Fe(PM-AzA)2(NCS)2] spin-crossover molecular solid. The light-induced excited spin-state trapping process switches the molecules from low spin to high spin (HS) states on the sub-picosecond timescale. The change of the electronic state (<50 fs) induces a structural reorganiza...

The theory of optimal control together with that of transient probe absorption spectroscopy are applied for control and detection of molecular wave packet dynamics in the weak response regime. We obtain a globally optimal pump–dump control field which drives the initial state to the predefined target, focused at the inner-turning point region of the electronic ground state potential. As for the...

The effects of compression on the structural and electronic properties of liquid rubidium are studied along the melting curve by means of a first-principles molecular-dynamics simulation. It is shown that the calculated pair distribution functions g(r) are in good agreement with the experimental results for a wide range of pressures; the liquid rubidium is compressed uniformly at 2.5 GPa, and t...

Luminescence spectra of organometallic molecules in crystals or glasses are discussed and interpreted by using the time-dependent Ž . theory of electronic spectroscopy. Emphasis is placed on determining bond length and bond angle changes excited-state distortions between the ground and excited electronic states. The physical meaning of the dynamic processes and the molecular properties are desc...

The ring opening of a dithienylethene photoswitch incorporated in a bridged boron-dipyrromethene - dithienylethene molecular dyad was investigated with ultrafast spectroscopy. Coherent vibrations in the electronic ground state of the boron-dipyrromethene are triggered after selective photoexcitation of the closed dithienylethene indicating vibrational coupling although the two moieties are elec...