The A [(2)B1] <--X [(2)A2] band system between 380 and 420 nm was observed in a supersonic jet expansion. The allyl radical was found to dissociate following electronic excitation, releasing a hydrogen atom. Monitoring the appearance of the hydrogen atom photoproduct as a function of the excitation laser wavelength, similar spectral features are observed as in earlier absorption experiments. Ti...

Understanding the effects of aggregation on exciton relaxation and energy transfer is relevant to control photoinduced function in organic electronics and photovoltaics. Here, we explore the photoinduced dynamics in the low-temperature aggregated phase of a conjugated polymer by transient absorption and coherent electronic two-dimensional (2D) spectroscopy. Coherent 2D spectroscopy allows obser...

We have investigated the ultra-fast carrier dynamics in Molecular Beam Epitaxy (MBE)-grown InAs/ InGaAs/GaAs quantum dots (QDs) emitting at 1.3 lm by time resolved photoluminescence (TRPL) upconversion measurements with a time resolution of about 200 fs. Changing the detection energies in the spectral region from the energy of the quantum dots excitonic transition up to the barrier layer absorp...

A series of new 8-arylhydrazono-2-(benzylsulfanyl)-7H-purin-6-ones 6 were synthesized, their electronic absorption spectra in different organic solvents of varying polarities were investigated and their acid dissociation constants in both the ground and excited states were determined spectrophotometrically. The tautomeric structures of such products were elucidated by spectral analyses and corr...

Wavelength-resolved femtosecond transient absorption spectroscopy is used to follow the electronic dynamics of single-walled carbon nanotubes in polymers following visible photoexcitation. Electron-hole (e-h) pairs give rise to sharp features in the transient spectra that decay in amplitude and exhibit rapid spectral shifts. The decay reflects (e-h) recombination on both short (1.3 ps) and long...

ZnFe2O4 nanocomposites have been prepared by a simple co‐precipitation method. The prepared samples were characterized by Scanning Electron Microscopy (SEM), Powder X‐ray Diffraction (XRD), Energy Disperse X‐ray Analysis (EDX), Transmission electron microscopy (TEM) and UV‐visible absorption spectral techniques. Conductivity measurements show a transition from ferrimagnetism to...

The absorption and fluorescence spectra of benzanilide (BA) and diphenyl carbazide (DPC) in solvents of different polarities and pH have been analysed. The spectral characteristics of DPC and BA are compared with diphenyl amine molecule. In water and methanol, a dual fluorescence is observed for both DPC and BA molecules. The normal stokes shifted emission originates from a locally excited pi* ...

A new Schiff base ligands (H2L -H2L 3) was synthesized by the condensation reaction of 4-acyl pyrazolones and 2-benzothiazolyl thiosemicarbazide. The ruthenium(II) Schiff base complexes were prepared by the interaction of the ligands with [RuHCl(CO)(EPh3)2(B)] (E=P/As; B=PPh3/AsPh3/py). They were characterized by elemental analysis, IR, UV-vis, 1H, 13C, and 31P NMR spectral data. The interactio...

The electronic response of a composite consisting of aligned metallic cylinders in vacuum is investigated, on the basis of photonic band structure calculations. The effective long-wavelength dielectric response function is computed, as a function of the filling fraction. A spectral representation of the effective response is considered, and the surface mode strengths and positions are analyzed....

We study spectral gratings obtained as a result of two-photon excitation of the lowest electronic transition of several tetrapyrrole molecules with phase-locked pairs of femtosecond pulses. A particular dependence of these gratings on temperature indicates that mirror symmetry is present between two-photon absorption (TPA) and one-photon fluorescence spectra for non-centrosymmetrical chlorin, b...