Ligand Exchange Strategy for Tuning of Helicity Inversion Speeds of Dynamic Helical Tri(saloph) Metallocryptands

We developed a new strategy, ligand exchange strategy, for tuning the response speeds of helicity inversion of a metal-containing helical structure. This is based on the exchange of the two axial amine ligands of the octahedral Co³⁺ centers in the metallocryptands [LCo₃X₆] (X=axial amine ligand). The response speeds of the helicity induction were controlled by using different combinations of achiral and chiral amines as the starting and entering ligands, respectively. The response speeds of the helicity inversion from P to M were also tuned by using different combinations of chiral amines.     

Photo-curable organically modified silicate-phosphate alternating copolymer for photonics applications

Photo-curable vinyl modified silicate-phosphate alternating copolymers were prepared by a direct condensation of organochlorosilane and organophosphoric acid in a solvent-free condition. The obtained copolymers have complete alternating copolymer structure of silicate and phosphate unit, where the main oxo chain consist of –(Si–O–P–O) _n -network. They exhibited an excellent solubility of ionic species such as ionic organic dyes. It was also demonstrated the photo-reduction of Au⁺ ions to form Au nano particles for plasmonics applications. Micro patterns were also fabricated by soft lithographic processes. These results indicate that the photo-curable alternating copolymers are one of promising materials for advanced optical information processing devices.     

Conductive Nanoscopic Fibrous Assemblies Containing Helical Tetrathiafulvalene Stacks

Tetrathiafulvalenes (TTF) S‐TTF and R‐TTF having four chiral amide end groups self‐organize into helical nanofibers in the presence of 2,3,5,6‐tetrafluoro‐7,7′,8,8′‐tetracyano‐p‐quinodimethane (F₄TCNQ). The intermolecular hydrogen bonding among chiral amide end groups and the formation of charge‐transfer complexes results in a long one‐dimensional supramolecular stacking, and the chirality of the end groups affects the molecular orientation of TTF cores within the stacks. Electronic conductivity of a single helical nanoscopic fiber made of S‐TTF and F₄TCNQ is determined to be (7.0±3.0)×10^?4 S cm^?1 by point‐contact current‐imaging (PCI) AFM measurement. Nonwoven fabric composed of helical nanofibers shows a semiconducting temperature dependence with an activation energy of 0.18 eV.     

Synthesis of polymer particles possessing radical initiating sites on the surface by emulsion copolymerization and construction of core–shell structures by a photoinduced atom transfer radical polymerization approach

The crosslinked polystyrene particles possessing photofunctional N,N‐diethyldithiocarbamate groups on their surface were prepared by free‐radical emulsion copolymerization of a mixture of styrene, divinylbenzene and 4‐vinylbenzyl N,N‐diethyldithiocarbamate with redox system as an initiator under UV irradiation. In this copolymerization, the inimer 4‐vinylbenzyl N,N‐diethyldithiocarbamate acted the formation of hyperbranched structures by living radical photopolymerization. The particle sizes (number‐average particle diameter = 214–523 nm) were controlled by varying the feed amount of surfactant and size distributions were relatively narrow. Subsequently, core–shell particles were synthesized by photoinduced atom transfer radical polymerization approach of methyl methacrylate initiated by photofunctional polystyrene particles as a macroinitiator. Such core–shell particles were stabilized sterically by grafted chains in organic solvents. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1771–1777, 2007     

Optically specific detection of D- and L-lactic acids by a flow-injection dual biosensor system with on-line microdialysis sampling.

A flow-injection dual biosensor system with microdialysis sampling is proposed for the simultaneous determination of D-lactic and L-lactic acids. The dialysate from the microdialysis tube is delivered to a sample loop of the six-way autoinjector and then automatically injected into the flow-injection line with a dual enzyme electrode arranged in perpendicular to the flow direction. The dual enzyme electrode is constructed by hybridizing a poly(1,2-diaminobenzene) film into two sensing parts which respond selectively to D-lactic and L-lactic acids, respectively, without any cross-reactivity. The proposed flow-injection analysis method can be successfully applied to the simultaneous determination of D,L-lactic acids in alcoholic beverages.     

Competing Roles of Two Kinds of Ligand during Nonclassical Crystallization of Pillared-Layer Metal-Organic Frameworks Elucidated Using Microfluidic Systems

To diversify metal-organic frameworks (MOFs), multi-component MOFs constructed from more than two kinds of bridging ligand have been actively investigated due to the high degree of design freedom afforded by the combination of multiple ligands. Predicting the synthesis conditions for such MOFs requires an understanding of the crystallization mechanism, which has so far remained elusive. In this context, microflow systems are efficient tools for capturing non-equilibrium states as they facilitate precise and efficient mixing with reaction times that correspond to the distance from the mixing point, thus enabling reliable control of non-equilibrium crystallization processes. Herein, we prepared coordination polymers with pillared-layer structures and observed the intermediates in the syntheses with an in-situ measurement system that combines microflow reaction with UV/Vis and X-ray absorption fine-structure spectroscopies, thereby enabling their rapid nucleation to be monitored. Based on the results, a three-step nonclassical nucleation mechanism involving two kinds of intermediate is proposed.     

An arrayed-window microfluidic device for observation of mixed nanoparticles with an X-ray free-electron laser

Optical Review - A microfluidic device was developed for coherent diffraction imaging using an X-ray free-electron laser (XFEL-CDI). Liquid samples, which are separately packed in reservoirs of the...     

Design,synthesis, and evaluation,derivatives of the fat-accumulation inhibitor ternatin: toward ternatin molecular probes

Ternatin, a cyclic heptapeptide derived from mushroom, strongly inhibits fat accumulation in 3T3-L1 adipocytes. However, its mechanism of action remains unclear. In this Letter, we designed, synthesized, and evaluated its derivatives for use as molecular probes to isolate its target protein. Finally, we successfully established a pair of ternatin molecular probes.