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Showing 1 to 18 of 18 for “"excited state lifetime"”.
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First principles calculations of transition metal complexes for artificial photosynthesis
… generation efficiency a long charge transfer excited state lifetime is necessary. Additionally, an absorption peak in the visible region is required for the molecule to absorb sunlight. To investigate the absorption peak and properties associated with the excited state lifetime of light …
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Laser-molecule Interactions And The Effects Of Permanent Dipoles
… the permanent dipole moments of two molecular states involved in a transition, are investigated for a variety of electromagnetic field-molecule interactions. Both analytical and exact numerical techniques are used to solve the time-dependent Schrodinger equation and to obtain the temporal …
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Spectroscopic Studies of Chlorophyll a Complexes with Trinitro-Substituted Flourene Derivatives
Absorption, fluorescence, and excited-state lifetime studies of chlorophyll a (Chl a) with fluorene, 2-(2,4,7-Trinitro-fluoren-9-ylideneaminooxy)-propionic acid (TFPR), 2- (2,4,7-Trinitro-fluoren-9-ylidenemethyl)-phenol, (TFPH), and 9-Isopropylidene-2,4,7- trinitro-9H-fluorene (ITNF) have been …
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Time resolved fluorescence of CdSe nanocrystals using single molecule spectroscopy
… of averaging over the ensemble. Studies of the excited state lifetime of band edge fluorescence from single NCs reveal multiexponential relaxation dynamics that stem from fluctuations of non-radiative decay rates for the band edge exciton. Analysis of these fluctuations allows us to extract …
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Modification of Excited State Behavior with Ligand Substitution in Ru(II),Rh(III) Bimetallic Supramolecular Complexes
… photophysical properties of the molecule. The excited state lifetime of the complex with a dcmbpy terminal ligand was 93 ns while the excited state lifetimes of the complexes with a bpy or Me₂bpy terminal ligand were 44 ns and 47 ns, respectively. Ligand substitution was shown to influence the …
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THE EMISSION OF PYRIDINE AND POLYPYRIDINECHROMIUM(III) COMPLEXES IN RIGID AND FLUID MEDIA.
The excited state emissions and lifetimes of [Cr(bipy)₃]³⁺, cis – [Cr(bipy)₂Cl₂]⁺, trans – [Cr(py)₄FBr]⁺, cis – [Cr(phen)₂F₂]⁺, and trans – [Cr(py)₄F₂]⁺ were studied in hydroxylic and nonhydroxylic solvents at 77 K and as a function of temperature. The emission characteristics are determined by the …
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Optimizing the excited state processes of conjugated polymers for improved sensory response
… by integrating chromophores with long-lived excited states into the polymer backbone. The first chromophore we targeted, triphenylene, has a symmetrically-forbidden ground state transition, resulting in a long excited state lifetime. Chapter 2 describes the synthetic incorporation of …
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Probing the Redox and Photophysical Properties of Ru(II)-Pt(II) Supramolecular Complexes as Efficient Photodynamic Therapy Agents
… is known in [Ru(Ph₂phen)₃]²+ to provide enhanced excited state lifetime and increase quantum efficiency for singlet oxygen generation in comparison to the phen analog (Φ₁₀₂ = 0.97, Ph₂phen and Φ₁₀₂ = 0.54, phen). The redox and photophysical properties were analyzed at each synthetic step providing …
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On The Nature Of Excited States In Ruthenium Complexes: Towards Renewable Energy
… properties (spectra, quantum yields and lifetimes) of ruthenium-polypyridyl complexes are investigated to better understand the effects of electronic mixing on metal-to-ligand-charge-transfer (3MLCT) excited state properties and how metal-centered (3MC) excited states affect the …
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Optical studies of ion-bombarded gallium arsenide
… microcrystal size implies a short time for an excited carrier to reach, and to be scattered by, the microcrystal boundary, thus limiting the excited-state lifetime and broadening the excited-state energy. An alternative uncertainty-principle argument is also given in terms of the …
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Spectroscopic characterization and photochemistry of nitrogen-containing molecules relevant to Titan's atmosphere
… vibronic coupling to a nearby second electronic excited state, and the S<sub>0</sub>-S<sub>1</sub>origin was found to be weak, due to the near cancellation of the transition dipole moment upon electronic excitation. The phenylcyanomethyl radical (PCM, Ph-ĊH-C≡N), a doubly resonance-stabilized …
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Transient Photophysics of Bismuth Halide Semiconductors for Optoelectronic Applications
… spectroscopy to show that the charge carrier lifetime in Cs2AgBiBr6 thin films is 1.4 μs. This is significantly longer than previous estimates based on time-resolved photoluminescence measurements, which measure the radiatively decaying carriers, but is a less sensitive probe of the high …
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Luminescent Lanthanide Complexes and Nanoparticles for Biological Applications
… applications because of their long emission lifetimes, sharp emission bands, color purity, resistance to photobleaching, and enhanced signal-to-noise ratios. Their practical use in aqueous and biological systems requires organic chromophores or other organic ligands that provide water …
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Quantum Nuclear Dynamics: Application to Spin-Forbidden Transitions and Lifetime of Vibrational States
… - nK range) can be prepared in specific quantum states and used for a variety of applications, such as quantum computing and ultracold chemistry. Theoretical predictions of the spectroscopic constants and the lifetimes of the vibrational quantum states of these molecules are needed for selecting …
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DEVELOPMENT OF HIGH LEVEL AB INITIO METHODS TO DESCRIBE NONADIABATIC EVENTS AND APPLICATIONS TO THE EXCITED STATES OF SMALL BIOLOGICAL MOLECULES
… studied in lieu of the larger target system. The excited state dynamics of 8-oxoguanine (8-oG) and its anion are studied in order to assess the possibility of taking part in an electron transfer mechanism to repair a nearby cyclobutane pyrimidine dimer (CPD). It is found that barriers on the anion …
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Earth-Abundant Metal Complexes Binding N-Heterocyclic Carbene-Based Ligands for the Photocatalytic Carbon Dioxide Reduction Reaction
… is attributed to the unusual long-lived excited state lifetime of these complexes in a microsecond range, as shown by the transient absorption spectroscopy (TAS) study. The Ni(II) CNC-pincer complex with monodentate Br ligand is also investigated here, yielding a comparable amount of …
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Design and Synthesis of Mixed-Metal Supramolecular Complexes Incorporating Specialized Light Absorbing Units to Investigate Processes Relevant to Catalyst Function
… light absorbing units to probe perturbation of excited-state properties by ligand deuteration and long-term complex stability via racemization of initially enantiopure light absorbing subunits. Varying bidentate polypyridyl terminal ligands (TL), bridging ligands (BL), reactive metal center …
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The Structure of the RC-LH1 Complex from Rps. acidophila: Optical Single-Molecule Spectroscopy and Numerical Simulations
… of the localization patterns of the LH1 exciton states revealed that the two lowest exciton states, k=1 and k=2, each localize in characteristic areas of the LH1 aggregates, where the values for the nearest-neighbor interactions between the pigments are significantly increased. With this …