Synthesis and application of head-to-head-type styrene dimers bearing two fluoroalkyl end-groups

Head-to-head-type styrene and substituted styrene dimers bearing two fluoroalkyl end-groups have been efficiently synthesized by a simple reaction of perfluoroalkyl iodide with styrene under radical conditions as a mixture of meso and racemic forms. The meso form obtained from the mixture by recrystallization gave a crystal suitable for X-ray diffraction study and the crystal structure was found to be based on π-stacking of benzene rings and aggregation of fluoroalkyl chains. Dynamic light scattering measurements showed that meso-styrene dimers bearing two fluoroalkyl end-groups can form the nanometer size-controlled self-assemblies through the intermolecular π-stacking of benzene rings and aggregation of end-capped fluoroalkyl groups in methanol.

α-Trifluoromethyl Chalcones as Potent Anticancer Agents for Androgen Receptor-Independent Prostate Cancer

α-Trifluoromethyl chalcones were prepared and evaluated for their antiproliferative activities against androgen-independent prostate cancer cell lines as well as five additional types of human tumor cell lines. The most potent chalcone 5 showed superior antitumor activity in vivo with both oral and intraperitoneal administration at 3 mg/kg. Cell-based mechanism of action studies demonstrated that 5 induced cell accumulation at sub-G1 and G2/M phases without interfering with microtubule polymerization. Furthermore, several cancer cell growth-related proteins were identified by using chalcone 5 as a bait for the affinity purification of binding proteins.     

Solid-Phase Radical Polymerization of Halogen-Bond-Based Crystals and Applications to Pre-Shaped Polymer Materials

Liquid vinyl monomers were converted into solid crystals via halogen bonding. They underwent solid-phase radical polymerizations through heating at 40 °C or ultraviolet photo-irradiation (365 nm). The X-ray crystallography analysis showed the high degree of monomer alignment in the crystals. The polymerizations of the solid monomer crystals yielded polymers with high molecular weights and relatively low dispersities because of the high degree of the monomer alignment in the crystal. As a unique application of this system, the crystalized monomers were assembled to pre-determined structures, followed by solid-phase polymerization, to obtain a two-layer polymer sheet and a three-dimensional house-shaped polymer material. The two-layer sheet contained a unique asymmetric pore structure and exhibited a solvent-responsive shape memory property and may find applications to asymmetric membranes and polymer actuators.     

Short Radiative Lifetime and Non-Triplet Sensitization in Near-Infrared-Luminescent Yb(III) Complex with Tripodal Schiff Base

We prepared Ln(III) (Ln=Eu, Gd, and Yb) complexes with a tripodal Schiff base, tris[2-(5-methylsalicylideneimino)ethyl]amine (H₃L) and studied their photophysical properties. Upon ligand excitation, YbL showed Yb(III)-centered luminescence in the near-infrared region. While the overall quantum yield (0.60(1)%) of YbL in acetonitrile was moderate among the reported values for Yb(III) complexes, its radiative lifetime (0.33(2) ms) was significantly shorter than those reported previously. We propose that the ligand-to-metal charge-transfer (LMCT) state mediated the sensitization in YbL. The emission and excitation spectra of EuL indicated the participation of the LMCT state in the sensitization. The radiative lifetime (0.84(7) ms) for EuL in the solid state was rather short compared to those of reported Eu(III) complexes. Our results show that the Yb(III) complex with the Schiff base ligand has two features: the short radiative lifetime and the non-triplet sensitization path.     

Dissolution tests for self-setting calcium phosphate cement-containing nifedipine

Nifedipine-containing calcium phosphate cement (CPC) was prepared, and nifedipine (NF) release from this preparation was evaluated by the shaking method (SK), Japanese Pharmacopoeia XIV (JPXIV) paddle method (PD), and JPXIV flow-through cell method (FT). The release of NF from the CPC preparation continued for 7 d or longer by all these methods. This suggests that the release of NF can be controlled by preparing NF-containing CPC. The release pattern of NF from CPC in these tests was found to follow the Higuchi equation. However, the Higuchi constant differed among the three dissolution tests, probably because the apparent tortuosity of capillary system (tau) varied.     

Synthesis of large-pore phenylene-bridged mesoporous organosilica using triblock copolymer surfactant

Periodic mesoporous benzene-silicas with large pores of 6.0 to 7.4 nm in diameter are synthesized using triblock copolymer as a template. These mesoporous materials have a well-defined hexagonal rod morphology and high thermal stability up to 823 K in air.     

Collapse of valence transition in Yb0.8Y0.2InCu4: pressure-induced weak ferromagnetism

We investigated the magnetization of Yb0.8Y0.2InCu4 as a function of temperature down to 0.6 K, pressure up to 1.2 GPa, and magnetic field up to 9 T. The valence transition temperature of Yb0.8Y0.2InCu4 is lowered with applying pressure. At 0.8 GPa, collapse of the valence transition and ferromagnetic ordering occur almost simultaneously. The ferromagnetic phase at 1.2 GPa is characterized by a low Curie temperature of 1.7 K and an extremely small ordered moment of 0.05 micro(B) per Yb. Some effect of screening the ordered moment may play a key role in the ferromagnetism and the valence transition.     

Achievement of a 920-MHz high resolution NMR

We have developed a 920-MHz NMR system and performed the proton NMR measurement of H(2)O and ethylbenzene using the superconducting magnet operating at 21.6 T (920 MHz for proton), which is the highest field produced by a superconducting NMR magnet in the persistent mode. From the NMR measurements, it is verified that both homogeneity and stability of the magnet have a specification sufficient for a high resolution NMR.