| 1. |
- Abrahamsson, M. L. A., et al.
(författare)
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Ruthenium-manganese complexes for artificial photosynthesis : Factors controlling intramolecular electron transfer and excited-state quenching reactions
- 2002
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Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 41:6, s. 1534-1544
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Tidskriftsartikel (refereegranskat)abstract
- Continuing our work toward a system mimicking the electron-transfer steps from manganese to P-680(+) in photosystem II (PS II), we report a series of ruthenium(II)-manganese(II) complexes that display intramolecular electron transfer from manganese(II) to photooxidized ruthenium(III). The electron-transfer rate constant (k(ET)) values span a large range, 1 X 10(5)-2 x 10(7) s(-1), and we have investigated different factors that are responsible for the variation. The reorganization energies determined experimentally (lambda = 1.5-2.0 eV) are larger than expected for solvent reorganization in complexes of similar size in polar solvents (typically lambda approximate to 1.0 eV). This result indicates that the inner reorganization energy is relatively large and, consequently, that at moderate driving force values manganese complexes are not fast donors. Both the type of manganese ligand and the link between the two metals are shown to be of great importance to the electron-transfer rate. In contrast, we show that the quenching of the excited state of the ruthenium(II) moiety by manganese(II) in this series of complexes mainly depends on the distance between the metals. However, by synthetically modifying the sensitizer so that the lowest metal-to-ligand charge transfer state was localized on the nonbridging ruthenium(II) ligands, we could reduce the quenching rate constant in one complex by a factor of 700 without changing the bridging ligand. Still, the manganese(II)-ruthenium (III) electrontransfer rate constant was not reduced. Consequently, the modification resulted in a complex with very favorable properties.
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| 2. |
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| 3. |
- Agaton, C., et al.
(författare)
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Affinity proteomics for systematic protein profiling of chromosome 21 gene products in human tissues
- 2003
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Ingår i: Molecular & Cellular Proteomics. - 1535-9476 .- 1535-9484. ; 2, s. 405-
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Tidskriftsartikel (refereegranskat)abstract
- Here we show that an affinity proteomics strategy using affinity-purified antibodies raised against recombinant human protein fragments can be used for chromosome-wide protein profiling. The approach is based on affinity reagents raised toward bioinformatics-designed protein epitope signature tags corresponding to unique regions of individual gene loci. The genes of human chromosome 21 identified by the genome efforts were investigated, and the success rates for de novo cloning, protein production, and antibody generation were 85, 76, and 56%, respectively. Using human tissue arrays, a systematic profiling of protein expression and subcellular localization was undertaken for the putative gene products. The results suggest that this affinity proteomics strategy can be used to produce a proteome atlas, describing distribution and expression of proteins in normal tissues as well as in common cancers and other forms of diseased tissues.
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| 4. |
- Agrell, H. G., et al.
(författare)
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Conductivity studies of nanostructured TiO2 films permeated with electrolyte
- 2004
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 108:33, s. 12388-12396
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Tidskriftsartikel (refereegranskat)abstract
- Charge transport in nanostructured TiO2 films permeated with an electrolyte was studied, using temperature-dependent conductivity and electron accumulation measurements. Two regions for charge transport were distinguished from the relationship between conductivity and electron concentration. In the first region (similar to1-20 electrons per TiO2 particle), the effective electron mobility is dependent on the electron concentration and values between 7 x 10(-4) and 78 x 10(-4) cm(2) V-1 s(-1) were determined. The activation energy of the mobility was similar to0.3 eV. The charge transport can be described with a trapping/detrapping model that involves localized band-gap states. In the second region (> 20 electrons per TiO2 particle), the effective electron mobility is independent of electron concentration and values of similar to150 x 10(-4) cm(2) V-1 s(-1) are calculated. The activation energy of mobility is in the range of 0-0.15 eV, depending on the electrolyte. Transport of electrons in the conduction band seems to be the most applicable model.
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| 5. |
- Ahuja, Rajeev, et al.
(författare)
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Electronic and optical properties of lead iodide
- 2002
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 92:12, s. 7219-7224
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Tidskriftsartikel (refereegranskat)abstract
- The electronic properties and the optical absorption of lead iodide (PbI2) have been investigated experimentally by means of optical absorption and spectroscopic ellipsometry, and theoretically by a full-potential linear muffin-tin-orbital method. PbI2 has been recognized as a very promising detector material with a large technological applicability. Its band-gap energy as a function of temperature has also been measured by optical absorption. The temperature dependence has been fitted by two different relations, and a discussion of these fittings is given.
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| 6. |
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| 7. |
- Amira, S., et al.
(författare)
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Derivation and evaluation of a flexible SPC model for liquid water
- 2004
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Ingår i: Chemical Physics. - : Elsevier BV. - 0301-0104 .- 1873-4421. ; 303:3, s. 327-334
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Tidskriftsartikel (refereegranskat)abstract
- Molecular dynamics simulations of a new flexible water model are presented. The potential function is based on the simple point charge (SPC) model combined with an accurate experimental quartic intramolecular potential (CCL). This potential not only reproduces the key structural, dynamical and thermodynamical properties of liquid water, but also generates the correct values for both the absolute O-H vibrational frequency and the gas-to-liquid frequency shift. Thus, the model yields a value of ca. 3420 cm(-1) for the peak maximum of the anharmonic OH stretching band for liquid water (experiment 3400 cm(-1)) and a corresponding gas-to-liquid downshift of -300 cm(-1) (experiment -310 cm(-1)). The paper also emphasizes the importance of parameterizing correctly both the harmonic and anharmonic force constants in the gas-phase when developing flexible water models to be used in the liquid state.
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| 8. |
- Amira, S., et al.
(författare)
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Molecular dynamics simulation of Fe2+(aq) and Fe3+(aq)
- 2004
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Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 108:1, s. 496-502
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Tidskriftsartikel (refereegranskat)abstract
- Molecular dynamics simulations of single-ion Fe2+(aq) and Fe3+(aq) solutions have been performed with two rigid-water models (SPC and SPC/E) and a newly constructed SPC-based flexible-water model (SPC+CCL). The SPC+CCL water model in combination with effective Fe2+ and Fe3+ ion-water potentials manages to reproduce many experimental structural and dynamical properties of the solutions. Special attention is given to the large ion-induced frequency shifts of the OH stretching bands, which are also well reproduced by the SPC+CCL model.
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| 9. |
- Amnell, Tobias, et al.
(författare)
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Code Synthesis for Timed Automata
- 2002
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Ingår i: Nordic Journal of Computing. - 1236-6064. ; 9:4, s. 269-300
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Tidskriftsartikel (refereegranskat)
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| 10. |
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