Strukturviskosimetrische Messungen von Zellulosederivaten in organischen Lösungsmitteln und die Beeinflussung ihrer Viskositäten durch Zusätze,I

Ohne Zusammenfassung Herrn Prof. Wo. Ostwald danke ieh für freundliche Anregung und weitgehende Beratung vorliegender Arbeit, Herrn Dr. H. Erbring for seine Hilfe bei der Abfassung des Manuskriptes.     

Radiation Chemical Studies of Protein Reactions: Effect of Irradiation Atmosphere and Temperature on Optical Rotation

When protein in various atmospheres such as N₂, O₂, H₂, CO₂, and NH₃ is irradiated by γ rays form a ⁶⁰Co source, the changes in the internal relationships of the atoms in the protein molecule vary with the gases composing the irradiation atmosphere. An empirical equation for the optical rotation was obtained. Protein irradiated by γ rays showed the effect of temperature by changes in the internal relationships of the atoms in the protein molecule. An empirical equation for the optical rotation was obtained. The behavior of optical rotation shows a similar dependence on irradiation atmosphere and temperature as shown in earlier viscosity experiments.     

Photoluminescent color tuning in fluorene derivative/copolymer composite films based on H-bonds

Reversible addition-fragmentation chain transfer (RAFT) polymerization is used to synthesize diblock and random copolymers of poly[(2-trifluoroethyl methacrylate)-co-(methacrylic acid)]. Copolymer films doped with fluorene derivatives comprised of pyridine groups exhibit reversible photoluminescent (PL) color tuning by adjusting the location of fluorene derivatives in H-bonds or non-H-bonds environments. The composite films exhibit green and blue photoluminescence with and without effective H-bonding between the pyridine ring in the fluorene derivative and the carboxylic acid side group, respectively. At elevated temperatures, the H-bonded structure dissociates and the fluorene derivative migrates to the hydrophobic block in the diblock polymer, and they do not form H-bonds upon cooling. However, re-formation of H-bonds also occurs upon cooling random copolymers. Moreover, adjusting the annealing temperature and the solvent annealing reversibly tunes the PL color in the diblock copolymer composite films.     

Mechanochromic Luminescence Characteristics of Pyridine‐Terminated Chromophores in the Solid State and in a Poly(vinyl alcohol) Matrix

Mechanoresponsive luminophores containing different substituted pyridine rings at the molecular terminus are synthesized and their photoluminescence properties are investigated. The solid chromophore with a 4‐substituted pyridine ring exhibits a reversible photoluminescent color change, while the 2‐substituted chromophore shows only a small change in luminescence, and the 3‐substituted chromophore displays an irreversible photoluminescent color change with mechanical grinding. A change of the sample color in response to mechanical grinding is also achieved for a dye‐dispersed poly(vinyl alcohol) film. Furthermore, a simultaneous acid and mechanoresponsive photoemission color change is achieved in the dye‐dispersed film.     

Radiation Chemical Studies of Protein Reactions: Effect of Alkaline-Earth Metals on the Breaking of Secondary Bonding in Protein

The radiation protective effect of the breaking of secondary bonding in protein was examined with alkaline-earth metals such as magnesium chloride, calcium chloride, strontium nitrate, and barium chloride, and alkaline metals and heavy metals such as lithium chloride, sodium chloride, potasium nitrate, ferrous chloride, ferric sulfate, nickel sulfate, aluminum nitrate, and zinc sulfate. An empirical equation for the viscosity change was obtained.     

Synthesis of Polybenzoacenes: Annulative Dimerization of Phenylene Triflate by Twofold C−H Activation

Polycyclic aromatic hydrocarbons (PAHs) represent an emerging class of π‐conjugated molecules in the area of optoelectronic devices and materials. Unprecedented synthetic routes to various PAHs from simple phenol derivatives by a palladium‐catalyzed annulative dimerization of phenylene triflate through twofold inter‐ and intramolecular C?H activation have been established. The initially formed partially fused PAHs can be smoothly transformed into a variety of fully fused PAHs by the Scholl reaction. Furthermore, the reactions of phenanthrene‐substituted aryl triflates proceeded regioselectively. The findings inspired the development of a rapid and efficient synthesis of polybenzoacene derivatives. This study not only allows transformation of phenyl triflates, but also discloses a new retrosynthetic strategy towards PAHs, especially polybenzoacenes.