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Modified bibenzimidazole ligands as spectator ligands in photoactive molecular functional Ru-polypyridine units? Implications from spectroscopy

2014, Meyer-Ilse, J., Bauroth, S., Bräutigam, M., Schmitt, M., Popp, J., Beckert, R., Rockstroh, N., Pilz, T.D., Monczak, K., Heinemann, F.W., Rau, S., Dietzek, B.

The photophysical properties of Ruthenium-bipyridine complexes bearing a bibenzimidazole ligand were investigated. The nitrogens on the bibenzimidazole-ligand were protected, by adding either a phenylene group or a 1,2-ethandiyl group, to remove the photophysical dependence of the complex on the protonation state of the bibenzimidazole ligand. This protection results in the bibenzimidazole ligand contributing to the MLCT transition, which is experimentally evidenced by (resonance) Raman scattering in concert with DFT calculations for a detailed mode assignment in the (resonance) Raman spectra.

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Artificial micro-cinderella based on self-propelled micromagnets for the active separation of paramagnetic particles

2013, Zhao, G., Wang, H., Sanchez, S., Schmidt, O.G., Pumera, M.

In this work, we will show that ferromagnetic microjets can pick-up paramagnetic beads while not showing any interaction with diamagnetic silica microparticles for the active separation of microparticles in solution.

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KLaF4 nanocrystallisation in oxyfluoride glass-ceramics

2013, De Pablos-Martín, A., Muñoz, F., Mather, G.C., Patzig, C., Bhattacharyya, S., Jinschek, J.R., Höche, T., Durán, A., Pascual, M.J.

Nanocrystallisation of the cubic and hexagonal polymorphs of KLaF 4 in a 70SiO2-7Al2O3-16K 2O-7LaF3 (mol%) glass has been achieved by heat treatment above the glass transition temperature. For treatment at 580°C, only the cubic structure crystallises, with a maximum crystallite size of ~9 nm. At higher temperatures, crystallisation of the hexagonal structure also takes place. The crystallisation process has been analysed using several thermal and structural techniques and is revealed to occur from a constant number of nuclei. The formation of a viscous barrier which inhibits further crystal growth and limits the crystal size to the nanometric range is observed. The title materials doped with lanthanide ions may be good candidates for optical applications.

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Local protonation control using plasmonic activation

2001, Singh, P., Deckert, V.

Localized protonation of 4-mercaptopyridine (4-MPY), activated by light in the presence of silver nanoparticles is monitored under ambient conditions using surface-enhanced Raman scattering (SERS) and tip-enhanced Raman scattering (TERS). The reaction can be controlled by the excitation wavelength and the atmospheric conditions, thus, providing a tool for site-specific control of protonation.

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The effect of supported MoOX structures on the reaction pathways of propene formation in the metathesis of ethylene and 2-butene

2014, Hahn, T., Kondratenko, E.V., Linke, D.

The kind of surface MoOX structures on Al2O3–SiO2 was found to determine propene selectivity in the metathesis of ethylene and 2-butene. Compared to isolated tetrahedral MoOX species, their polymerized octahedral counterparts show significantly lower activity for isomerisation of 2- to 1-butene thus hindering non-selective metathesis of these butenes. In addition, they reveal higher ability to engage ethylene in propene formation.