Near-Field and Polarized Evanescent Field Excited Fluorescence of Self-Organized Particle Arrays of Organic Dye

A wetting/dewetting process was utilized to prepare self-organized organic dye particles of micrometer and submicrometer size. Near-field scanning optical microscopy successfully identified near-field excited near-field fluorescence from single particles. The majority of the small particles with diameters around 2 mm or less, however, did not show fluorescence under near-field observation. In contrast, far-field fluorescence, when excited by a polarized evanescent field, was observed, with the intensity depending on the excitation polarization, indicating that molecules' transition moment within dye particles was oriented parallel to the substrate surface. Single particle fluorescence spectrum consistently showed an identical sharp peak with a large redshift, indicating that the particles were composed of identical dye aggregates similar to J-aggregates. These observations suggest that the near-field at the probe tip was polarized parallel to the probe axis. Another observation, that molecules were oriented in a similar direction among adjacent particles, suggests that the dewetting process contributed to the alignment of the molecular direction among adjacent particles, which further proves that the present specimen was formed by a self-organizing mechanism.     

Establishment of hybrid-derived offspring populations in the Ohomopterus ground beetles through unidirectional hybridization

An approach to deduce the mechanism of stabilization of the hybrid-derived populations in the Ohomopterus ground beetles has been made by comparative studies on the phylogenetic trees of the mitochondrial and nuclear DNA. A phylogenetic tree based on the internal transcribed spacer (ITS) of nuclear ribosomal gene roughly reflects the relations of morphological species group, while mitochondrial NADH dehydrogenase subunit 5 (ND5) gene shows a considerable different topology on the tree; there exist several geographically-linked lineages, most of which consist of more than one species. These results suggest that the replacement of mitochondria has occurred widely in the Ohomopterus species. In most cases, hybridization is unidirectional, i.e., the species A (♂) hybridized with another species B (♀) and not vice versa, with accompanied replacement of mitochondria of A by those of B. The results also suggest that partial or complete occupation of the distribution territory by a hybrid-derived morphological species. The morphological appearance of the resultant hybrid-derivatives are recognized as that of the original species A. Emergence of a morphological new species from a hybrid-derived population has been exemplified.     

Oxidation of alcohols with oxoperoxobis(N-phenylbenzohydroxamato)molybdenum(VI)

The title complex oxidizes primary and secondary alcohols to the corresponding carbonyl compounds. Stereoselective epoxidation of allylic alcohols is also described.     

Tris(1‐ethyl‐3‐methyl­imidazolium) hexa­chloro­lanthanate

In the title complex, (C₆H₁₁N₂)₃[LaCl₆], centrosymmetric octahedral hexa­chloro­lanthanate anions are located at the corners and face‐centers of the monoclinic unit cell. The ring H atoms of the cations interact with the Cl atoms of the anions via hydrogen bonding, and bifurcation of the hydrogen bonding is observed. Cation–cation interactions via hydrogen bonding between the ring H atoms and π‐electrons of aromatic rings are also observed as in other imidazolium salts.     

Organoaluminium reagents induced isomerization of 5-hydroxy-3,3,6-trimethyl-5-heptenoic acid δ-lactone to 2,2,5,5-tetramethyl-1,3-cyclohexanedione

Treatment of the title lactone and the related δ or ε-lactones with Et₂AlSR (R = Et or Ph) gave 1,3-cyclohexanediones or 1,3-cycloheptanediones in excellent yields.     

SCF MO INDO calculation of g-tensors of some σ-type radicals

The Longuet-Higgins and Pople type SCF MO theory was applied to the all-valence-electron systems of several -type radicals and their g-tensors were theoretically calculated with the Stone's equation. Principal values or diagonalyzed g-tensors were obtained and compared with experimental values in ESR spectra.     

Synthesis and application of chiral bisphosphines through lithiation-conjugate addition tandem cyclization of chiral alpha,beta,psi,omega-unsaturated bisphosphine oxide

Upon treatment with lithium diisopropylamide achiral and chiral alpha,beta,psi,omega-unsaturated bisphosphine oxides underwent lithiation-conjugate addition tandem cyclization to afford the corresponding endo-alpha,beta-unsaturated cyclic bisphosphine oxides; sequential stereoselective reduction of the cyclized bisphosphine oxide gave the corresponding trans- and cis-bisphosphines that were successfully applicable in a catalytic asymmetric hydrogenation as chiral bisphosphine ligands.     

Photopolymerization of methyl methacrylate in the presence of tertiary amines

The sensitization effect of tertiary amines on the photopolymerization of methyl methacrylate was studied. N,N-Dimethylbenzylamine, triethylamine, and N,N-dimethylaniline increased the rate of polymerization in this order, but pyridine did not show any effect. A free-radical mechanism was confirmed by the tacticity of polymer, the retarding effect of hydroquinone, and the copolymer composition with styrene. On the basis of the detailed kinetics of the sensitized polymerization and the ultraviolet spectra of the reaction mixtures, a sensitization mechanism is proposed, in which the excited monomer and the amine form a complex and generate an initiating radical.     

Synthesis of 4,5-diaminopyrrolo[1,2-a]quinoline derivatives by annulation of N,N-dialkyl[2-(pyrrol-1-yl)benzylidene]ammonium salts in the presence of an isocyanide

A facile synthetic method for 4,5-diaminopyrrolo[1,2-a]quinoline derivatives has been developed. Treatment of 2-(pyrrol-1-yl)benzaldehydes with secondary amine hydrochloride/NaI/TMSCl/Et₃N in the presence of an isocyano compound leads to the formation of 4-alkyl(or aryl)amino-5-dialkylaminopyrrolo[1,2-a]quinolines.     

Solvent extraction of alkali metal ions with chromium complexes

Solvent extraction of alkali metal ions by batch and counter-current distribution methods was investigated with tetrathiocyanatodiamminechromate(III) and tetrathiocyanatodianilinechromate(III) as reagents and nitromethane and nitrobenzene as organic solvents. The distribution ratios of alkali metal ions in the various systems were measured. Cesium was readily extracted with the aniline compound and nitrobenzene. The separation of sodium from potassium in trace amounts was possible by the counter-current distribution method.