Novel adducts of sulfides and 4-substituted 1,2,4-triazoline-3,5-diones ( TAD ) A similarity of TAD and singlet oxygen( 1O2 )

The 4-substituted 1,2,4-triazoline-3,5-diones( $\text{2}$ ) afford with sulfides( $\text{1}$ ) having acidic α-hydrogens the 1,4-disubstituted urazoles( $\text{3}$ ). Reactivity of the triazolinedione shows similarity in possible reaction modes with that of singlet oxygen.     

O-Alkylations of pyridoxine and pyridoxamine

O-Alkylations of pyridoxine 1 and pyridoxamine 5 were carried out in acetone in the presence of sodium ethoxide and potassium iodide to give 5-alkoxy-6-methyl-3,4-(bishydroxymethyl)pyridines 2a-j and 5-alkoxy-4-aminomethyl-6-methyl-3-hydroxyrnethylpyridines 6a-e .     

An efficient synthesis of 3-substituted 3H-pyrimidin-4-ones

[reaction: see text] A novel and practical synthesis of 3-substituted 3H-pyrimidin-4-ones is described. The key step involves the cyclization of enamide esters, derived from readily available beta-keto esters, with trimethylaluminum and various primary amines.     

Stereoselective total synthesis of ( + )-brefeldin A

A total synthesis of ( + )-brefeldin A, an antibiotic fungal metabolite, has been achieved stereoselectively starting from ( + )-mannitol and ( + )-glutamic acid.     

Photocontrolled microphase separation of block copolymers in two dimensions

A novel ABA-type triblock copolymer, where A and B correspond to azobenzene (Az) containing polymethacrylate and poly(ethylene oxide) (PEO), respectively, was synthesized by atom transfer radical polymerization. Langmuir-Blodgett monolayers showed characteristic microphase separation structures depending on the isomerization state of the Az unit. The trans-to-cis isomerization induced an anisotropic elongation of the domain of the Az polymer parallel to the rod maintaining the width. Thus, successful photocontrol of nanostructures formed by the block copolymer in the two dimensions was performed. A plausible model for the Az packing and PEO conformation is proposed.     

Structure-dependent photophysics studied in single molecules of polythiophene derivatives.

We report on the photophysical characterization at the single-molecule level of a graft copolymer consisting of a polythiophene backbone and long polystyrene branches. The presence of the branches prevents the polymer chain from forming a collapsed conformational state. The photophysical properties of the resulting solution-like conformation are studied by measuring single-molecule photobleaching dynamics, emission polarization anisotropy and emission spectra. The results are compared with those obtained on the same polythiophene derivative without the branches. It is found that the presence of the branches is a decisive factor in determining the photophysical properties of the polymers on the single-molecule level.     

A halide ion promoted electrochemical oxyselenenylation of olefins

A novel electrolytic transformation of olefins $\text{1}$ into oxyselenides $\text{2}$ has been performed in high yields and high regioselectivities by elctrolyzing olefins in protic solvents (MeOH, AcOH, H₂O-MeCN) containing Et₄NX (X = Cl, Br, I) and diphenyl diselenide using platinum foils.     

Excitation profiles of resonance raman spectra in condensed media

A simple model, obtained by reducing a multimode system to a simple coordinate, is proposed to explain the broadening of RRS in liquid or solid media. It is shown that the coherent excitation of the near continuous background of low-frequency modes can cause homogeneous broadening of RRS profiles. The model is applied to the excitation profile of β-carotene.     

Functional liquid-crystalline assemblies: self-organized soft materials

In the 21st century, soft materials will become more important as functional materials because of their dynamic nature. Although soft materials are not as highly durable as hard materials, such as metals, ceramics, and engineering plastics, they can respond well to stimuli and the environment. The introduction of order into soft materials induces new dynamic functions. Liquid crystals are ordered soft materials consisting of self-organized molecules and can potentially be used as new functional materials for electron, ion, or molecular transporting, sensory, catalytic, optical, and bio-active materials. For this functionalization, unconventional materials design is required. Herein, we describe new approaches to the functionalization of liquid crystals and show how the design of liquid crystals formed by supramolecular assembly and nano-segregation leads to the formation of a variety of new self-organized functional materials.