Reaction of N,N-dimethylselenocarbamoyl chloride with nucleophiles. Preparation of diselenocarbamates, selenothiocarbamates, and selenoureas

Reactions of N,N-dimethylselenocarbamoyl chloride prepared by using LiAlHSeH with nucleophiles such as lithium alkylselenolate, lithium alkylthiolate, and amines afford the corresponding diselenocarbamates, selenothiocarbamates, and selenoureas. The crystal structure of the Se-phenyl N,N-dimethyldiselenocarbamate was also determined by X-ray diffraction.     

Polyimide/Diamond Nanocomposites: Microstructure and Indentation Behavior

Polyimide/diamond nanocomposites have been synthesized from 4,4′‐diaminodiphenyl ether (ODA) and 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA). All the polyimides show non‐crystalline X‐ray diffraction. The frequent occurrence of particular interatomic distances (R) denoted by the non‐crystalline X‐ray diffraction maxima are determined. An ultramicro‐indentation technique is employed to evaluate the effects of nano‐diamond particles on the indentation behavior of polyimides. Indentation size effect is observed and discussed.

     

Synthesis and conversion of 2‐(pyrazol‐1‐yl)quinoxaline 4‐oxides

The reaction of 6‐chloro‐2‐hydrazinoquinoxaline 4‐oxide 1b with acetylacetone or benzoylacetone gave 6‐chloro‐2‐(3,5‐dimethylpyrazol‐i‐yl)quinoxaline 4‐oxide 5a or 6‐chloro‐2‐(3‐methyl‐5‐phenylpyrazol‐1‐yl)quinoxaline 4‐oxide 5b , respXectively. Compound 5a or 5b was converted into the pyrrolo[1,5‐a]quinoxaline 6a or 6b , triazolo[4,3‐a]quinoxaline 9a or 9b , and tetrazolo[1,5‐a]quinoxaline 10.     

Enantiospecific Photochemical Transformations under Elevated Pressure

Enantiospecific axial‐to‐point chiral transfer in light‐induced transformations was efficient under elevated pressure at high temperatures. Model photoreactions with atropisomeric compounds showed higher enantioselectivity in the photoproducts under elevated pressure. The ee values in the photoproducts were rationalized based on the increased stability of optically pure atropisomeric compounds at elevated pressure, even at high temperatures.     

Quinolone Analogues 12: Synthesis and Tautomers of 2‐Substituted 4‐Quinolones and Related Compounds

The 4‐quinolone‐2‐carboxylates 4a,b were converted into the 4‐quinolone‐2‐carbohydrazides 5a,b , hydrazones 6,7,10 , and related compounds 8,9,11 . The 4‐methoxyquinoline‐2‐carboxylate 12 was also transformed into the 4‐methoxyquinoline‐2‐carbohydrazide 13 , which was modified to the hydrazone 14 and related compound 15 . The antimicrobial activities of compounds 6b and 14 are described together with the 4‐oxo and 4‐hydroxy tautomers of compounds 4‐11 in deuteriodimethyl sulfoxide and deuteriotrifluoroacetic acid.     

Development of non-deterioration-type skin tissue phantom using silicone material

We developed a new type of three-layered skin tissue phantom using silicone material. This phantom maintains its optical properties in a certain period of time, typically about three months, which is much longer than about 30 min with our previous agar-type phantom. Experiments on spectral reflectance measurements and color analysis indicate the possibility of silicone-type skin tissue phantom.     

Synthesis,crystal structures,spectral, electrochemical and magnetic properties of di-µ-phenoxido-bridged dinuclear copper(II) complexes with N-salicylidene-2-hydroxybenzylamine derivatives: axial coordination effect of dimethyl sulphoxide molecule

The template reaction of salicylaldehyde and its substituted derivatives and 2-hydroxy-5-bromobenzylamine or 2-hydroxy-5-chlorobenzylamine with copper(II) acetate in dimethyl sulphoxide (dmso) afforded eight dinuclear Cu(II) complexes, [Cu₂(L)₂(dmso)₂] (H₂ L = N-salicylidene-2-hydroxy-5-bromobenzylamine, N-salicylidene-2-hydroxy-5-chlorobenzylamine and their 5-bromo, 5-nitro and 5-methyl-substituted salicylidene derivatives). These Cu(II) complexes were characterised by IR and UV-VIS-NIR spectroscopy, electric conductivity, cyclic voltammetry, and temperature dependence of magnetic susceptibilities (4.5–300 K). In the THF solution, the complexes are nonelectrolytes and exhibit a characteristic CT band due to phenoxido-bridging at 360–384 nm. In the cyclic voltammograms, an irreversible reduction process was observed at ?1.18–1.54 V vs Fc/Fc⁺. Single-crystal X-ray crystallography revealed that two Cu(II) ions were bridged by the two phenoxido-oxygen atoms of the two Schiff-base ligands with axial coordination of dmso molecules forming a square pyramid with a Cu-Cu distance of 3.0628(8)–3.0931(6) °A. In accordance with the crystal structures, the magnetic interaction between the two Cu(II) ions is relatively anti-ferromagnetic with ?2J value of 386–575 cm^?1. The axial coordination effect of the dmso molecule was discussed in relation to the correlation between the Cu-O-Cu angle and the ?2J value.