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Experimental and theoretical techniques were combined to investigate the behavior and dynamics of a polymer-dye molecule system. Findings revealed that single molecule spectroscopy, an experimental technique proves to be a method of choice to investigate the various conformations of a dye molecule and their interactions with the surrounding polymer matrix.

Two kinds of carbon nanotubes (CNTs) are selected to investigate hole-edge reactivity such as single-wall carbon nanotubes (SWNTs) and single-wall carbon nanohorns (SWNHs). The study is helpful to the understanding of hole-edge chemistry and would enable the production of well-designed carbonaceous materials with high functionality.

The electron-transfer process in mono- (NlP1) and multichromophoric (NlP3) triphenylamine core dendrimers carrying one and three peryleneimide electron accepter chromophores, are characterized using the combination of transient absorption and fluorescence experiments performed on a femtosecond to nanosecond time scale.

The electron-transfer process of a first generation dendrimer with a triphenylamine core substituted with one peryleneimide chromophore at the rim (N1P1) was investigated by steady-state and time-resolved spectroscopic techniques in two different solvents of medium and low polarity. Single photon counting experiments showed a fast charge separation and thermally activated back reaction, which is uncommon for polyaryl bridge or long distance through-space electron transfer.

The time-dependent spectral properties of a rigid, extended system consisting of three pentaphenylene units end-capped with perylene monoimide are studied by femtosecond transient absorption and single photon timing measurements. It is seen that quantum-chemical calculations performed on the system comprising of two pentaphenylene units end-capped with perylene monoimide support the experimental data.

The photological properties of seven new 8-(p-substituted)phenyl analogues of 4,4-difluoro-3,5-dimethyl-8-(aryl)-4-bora-3a,4a-diaza-s-indacene in several solvents are studied by means of absorption and steady-state and time-resolved fluorimetry. The fluorescence quantum yield and lifetime for each compound are lower in solvents with higher polarity due to an increase in the rate of nonradiative deactivation.

The conformational dynamics of a single molecule in a polymer matrix, which allows a direct visualization of the local free volume, is presented. The molecular structures of the two conformations of the dye molecule are described.

The carbon monoxide adsorption activity of small gold-cluster anions is measured by pulsed helium flow-reactor methods at room temperature. The pressure-dependent adsorption patterns give insight into (CO, O2) coadsorption phenomena on model-catalyst systems and may be exploited in further gas-phase experiments on coadsorption ad catalytic cycles.

The carotenoid and chlorophyll cation radicals in hydroxylamine treated PSII membranes from spinach are studied by 285 GHz high-field EPR spectroscopy. By using the inherent high resolution of high-field EPR in combination with 1D-oriented samples and knowledge of the g-tensor orientation, it is possible to determine directly the orientation of a radical with respect to the axis of orientation.

A temperature-dependant study is carried out for the platinum-nanoparticle-catalyzed electron-transfer reaction between hexacyanoferrate (III) and thiosulfate ions in the temperature range of 20-70 degree Celsius. The findings indicate that this behavior affected the temperature dependence of the catalytic reaction and the decrease in the catalyst surface area due to the increase of nanoparticle aggregation.

A study is conducted to investigate the [propagation of circular NAD(P)H autofluorescence and proton waves in individual living human neutrophils using high-speed fluorescence microscopy. the results reveal that physical-chemical self-organization of metabolism is a fundamental aspect of cell function.

The first measurement of the rate of excition-excition anihilation in J aggregates for which strong nonmonotonous temperature dependence is found is presented. The conclusion states that an excition hopping process occurs at low temperature, a coherent wave-packet-like excition transport occurs in the intermediate temperature region and a strong excition scattering occurs on optical phonons at high temperature.

Issues arising from the study of the interlayer excitation energy transfer between a carbazole derivative, 11-(9-carbazole)undecanoic acid, and two 9-anthroyloxy derivatives in Langmuir-Blodgett films are discussed. Four models were used to analyze the decay curves.

Manganese complexes of 2,2'-bipyridine (bpy) and 1,10-phenantroline (phen) have been synthesised in the supercages of cubic NaX and NaY and in the hypercages of the hexagonal NaEMT faujasites. The coordination and redox chemistry were studied with ESCA, CA, FT-IR, FT-Raman, diffuse reflectance and emission techniques. FT-IR/FT-Raman shows cis coordination for all complexes and a high Mn-N stretching frequency in the phen complexes as a result of steric constraints imposed by the ligand. [Mn(bpy) 2 ] 2+ in the different zeolites shows metal-to-ligand charge transfer (MLCT; at 495 nm); for [Mn(phen) 2 ] 2+ -NaY the MLCt is broadened owing to complex distortion. On MLCT excitation [Mn(bpy) 2 ] 2+ complexes show an ipsochromic shift in the emission and an increase in quantum yield with increasing steric restrictions imposed by the zeolite. The ipsochromic shift of the emission band of [Mn(phen) 2 ] 2+ in NaY results from the combined effect of the ligand field (this suggests emission from a CT state) and of coordinative distortion. The key factor influencing the emission properties is found to be the overall matrix-induced complex distortion. Cation stabilisation of the ligand anion affects emission indirectly. The decay times for [Mn-(bpy) 2 ] 2+ -NaY are in the millisecond range (7.5-11.5 ms). A proposed model for excitation and emission properties of zeolite-occluded Mn II complexes involves excitation of a quartet CT state, intersystem crossing and subsequent emission. The enhanced stability of the coordination sphere in the zeolite allows complexes to luminesce from a CT state, which is not detected in solution. The zeolite behaves as a supramolecular cryptating agent, protecting complexes from photodissociation., (Copyright © 1996 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)