Synthesis and characterization of flavylium salts having three types color depending on recrystallization conditions

Three types of flavylium salts (FVs, yellow, green and red) have been synthesized and the colors depended on recrystallization conditions. The existence of these color states was confirmed by diffuse reflectance spectra. The spectra were almost the same as the absorption spectra in ethanol solution. The molecular state of FVs in crystals will be the same as that in solutions. The crystal colors of the FVs are controlled by the recrystallization conditions.     

Radiation-induced polymerization of sodium allylsulfonate at high pressure

Irradiation of sodium allylsulfonate in aqueous solution at high pressure (up to 9000 kg/cm²) gave a deliquescent white powder which is insoluble in organic solvent. The product was addition polymer of allylsulfonate from the high-resolution NMR and infrared spectra. The rate of polymerization was proportional to the third and second powers of monomer concentration in the initial and later stages, respectively. From the high dependence of the rate on monomer concentration, the reaction was deduced to proceed in an associated monomer or micelle. The rate of polymerization was increased by addition of sodium chloride. The G value for monomer consumption was about 10⁴ at high pressure, which suggests that the degradative chain transfer is not important in the polymerization. Overall activation volumes were ?7 and ?5 ml/mole in the initial and later stages, respectively.     

A pressure and temperature study on solubility and micelle formation of sodium perfluorodecanoate in aqueous solution

Both the critical solution temperature (CST, or the Krafft temperature) and the critical solution pressure (CSP, or the Tanaka pressure) were determined for sodium perfluorodecanoate (NaPFDe) in water, and the result shows that the Krafft temperature is raised with the increase in the Tanaka pressure. A thermodynamic analysis has been made on the data for the critical micellization concentration (cmc) and of the solubility at various temperatures and pressures. The estimated change in the partial molal volume, resulting from micelle formation from the singly dispersed state and from the hydrated solid state, was found to be conspicuously higher for NaPFDe compared to hydrocarbon surfactants. This has been ascribed to the more pronounced role of carbon chain-water interactions and water structure effects of the fluorocarbon surfactants.     

The reaction of aryl methyl ketones with aromatic aldehydes in trimethylsilyl polyphosphate (PPSE). Formation of meso-2,4,6-trisubstituted-5-acyl-1,3-dioxanes

The reaction of aryl methyl ketones with three equivalents of aromatic aldehydes in the presence of trimethylsilyl polyphosphate (PPSE) afforded $\text{meso}$-2,4,6-trisubstituted-5-acyl-1,3-dioxanes yields.     

Drying dissipative patterns of biological polyelectrolyte solutions

Drying dissipative structural patterns of aqueous solutions of biological polyelectrolytes, sodium poly (α, L-glutamate; NaPGA) and poly (-L-lysine hydrobromide; PLL.HBr), were studied on a cover glass. Below the critical polymer concentration, m* (ca. 0.003 and ca. 0.01 monoM for NaPGA and PLL.HBr, respectively), the dried patterns shrank only around the center of the initial solution area wetted on a cover glass. Above the m* values, on the other hand, the drying pattern extended throughout the initial solution area. The m* values agreed excellently with the critical polymer concentrations, where the surface tensions started to decrease sharply as the polymer concentrations increased. The broad rings were always observed in the drying patterns of any solutions examined. The spoke-like cracks appeared at the polymer concentrations above the m* values and only in the area of the broad rings. Microscopic structures such as cross-like, rod-like, and block-like patterns formed irrespective of polymer concentrations. Especially, the city-road-like microscopic pattern was observed for PLL.HBr solutions, which strongly supports the formation of crystal structures of PLL.HBr that remain in the whole processes of dryness. These patterns were correlated deeply with the crystal-like orientation of the biological polyelectrolytes at the air–solution interfaces.     

Sedimentation and drying dissipative patterns of colloidal silica (560 nm in diameter) suspensions in a glass dish and a watch glass

The sedimentation and drying dissipative structural patterns formed during the course of drying colloidal silica spheres (CS550, 560 nm in diameter) in an aqueous suspension have been studied in a glass dish and a watch glass. Broad ring patterns were formed within 20 min in the suspension state by the convectional flow of the colloidal spheres and water. The sedimentary spheres always moved by the convectional flow of water, and the broad ring patterns became sharp with time. The sharpness of the broad rings was sensitive to the change in the room temperature and/or humidity. Colorful macroscopic structures were composed of the broad ring and wave-like patterns, and further colorful and beautiful microscopic fine patterns formed during the solidification processes based on the convectional and sedimentation structures. The drying patterns of the colloidal suspensions containing sodium chloride were different from the structures of CS550 or sodium chloride individuals, which support the synchronous cooperative interactions between the colloidal spheres and the salts.     

Syntheses of analgesics. Part XXX.. Conformational studies of diastereoisomeric quaternary ammonium salts of 1,2,3,4,5,6-Hexahydro-2,6-methano-3-benzazocines

The configuration of the quaternary ammonium salts (Va and Vb) from 3-benzyl-1,2,3,4,5,6-hexahydro-8-hydroxy-6,11-dimethyl-2,6-methano-3-benzazocine. (II) and 3-methyl-2-butenyl bromide was determined spectroscopically. Moreover, configurational studies on 3-benzyl (VIa and VIb) and 3-(3-methyl-2-butenyl)benzazocinium bromides (VIIa and VIIb) were also achieved.     

Degradation and isomerization of 1,2-dichloroethenes by photocatalytic reactions

The photocatalytic degradation and isomerization of trans- and cis-1,2-dichloroethenes (1,2-DCEs) by TiO₂ photocatalyst have been investigated using gas chromatography. The reaction half-life of 1,2-DCEs in nitrogen was longer than in dry air and oxygen, and the initial concentration of them affects the extent of the isomerization. The results indicate that the oxygen molecule and chlorine atoms play an important role in the degradation and isomerization of 1,2-DCE. It is also apparent that the photocatalytic degradation of 1,2-DCEs occurs on the TiO₂ surface.     

Kinetic analyses of colloidal crystallization in shear flow

Colloidal crystallization kinetics is studied in the shear flow of a suspension of colloidal silica spheres (110 nm in diameter), using a continuously-circulating type of stopped flow cell system. The crystallization rate from a suspension containing a small amount of nuclei and/or single crystals is high compared with that from a suspension containing no nuclei and/or single crystals. Crystal growth takes place at shear rates smaller than 3.4 s^–1 and at sphere concentrations higher than a volume fraction of 0.004.     

Furan derivatives. Part 9. Synthesis and properties of cyclohepta[cd]benzofurans

Cyclohepta[cd]benzofurans 1a-c were synthesized by heating (5-oxo-5H-benzocyclohepten-4-yloxy)acetic acids 7a-c with sodium acetate in acetic anhydride or by irradiation of 7a-c in acetonitrile. Several reactions such as protonation, catalytic hydrogenation, Diels-Alder reaction, acylation, and photoreaction were examined for 1a-b . The results show that cyclohepta[cd]benzofurans have both properties of heptafulvene and benzofuran. The carbon-carbon double bond in the furan ring of 1a has aromatic character, however, the carbon-carbon double bonds in the seven-membered ring have olefinic character.