In the binary system CH3CO2Na–H2O, crystallization temperature on slow cooling from a melt, glass transition temperature and crystallization temperature on slow heating from a quenched vitrified solid were measured by varying the CH3CO2Na concentration. The crystallization behaviour in the binary system CH3CO2Na–H2O is characterized as follows; (1) crystallization region of ice extends into the CH3CO2Na-rich side from the eutectic composition, (2) a hard crystallization region exists in the composition between CH3CO2Na 35wt% and 40wt%, (3) the crystallization temperature range of CH3CO2Na·3H2O is from −50 °C to −30 °C and very narrow.
The electrical conductivity of 2-(p-decyloxybenzylideneamino)-9-fluorenone (DBAF), which has a large π-electronic group, was investigated in the nematic state. The dark conductivity showed a positive anisotropy and was attributed to ionic conduction. The photocurrent was observed in the absorption region of DBAF and was enhanced by doping with 2,4,7-trinitro-9-fluorenone. The photocarriers seem to be generated from the excited state of DBAF by one photonic process.
The complexation of 18-crown-6 with primary ammonium chlorides [H(CH2)nNH3Cl, n=0, 1, 2, and 4] caused an increase in volume, which was attributable to the dehydration of the ammonium moieties. On the other hand, the apparent molal volumes of (CH3)4−nNHnCl (n=0–2) were not affected appreciably by the presence of the crown ether, and their complex stability seemed to be insignificant.
The photosensitized reduction of macrocyclic cobalt(III) complex, [Co(N4)(OH2)2]3+ (N4=Me64,11-dieneN4), occurs rapidly in an anaerobic [Ru(bpy)3]2+/[Co(N4)(OH2)2]3+/triethanolamine solution. The mechanistic implications of the photosensitized reaction are discussed.
Spin-lattice relaxation times (T1’s) of 57Fe were determined by the inversion recovery method to be 80 (±10) s at 293 K and 4 (±1) s at 303 K for Fe(CO)5 and ferrocene, respectively. Predominant relaxation mechanisms were considered to be chemical shift anisotropy and spin-rotation for the former and the latter complexes, respectively.
The critical mole fraction of hydrocarbon surfactant decreases with an increase in the oxyethylene unit of either fluorocarbon surfactant or hydrocarbon surfactant. This tendency is explicable in terms of regular solution theory if the depth of water penetration into the micellar interior is assumed to increase with an increase in the oxyethylene unit.
The structures of silver(I) complexes with cyclo(glycyl-L-histidyl), cyclo(L-methionyl-L-histidyl), and cyclo(L-histidyl-L-histidyl) were examined using 1H and 13C NMR. The NMR measurements suggest that the silver(I) ion links to the sulfur atom of thioether and the nitrogen atom of imidazole group of the above cyclic peptides, but not to their amide groups.
A succinate-complexed calcium phosphate has been synthesized by conducting the hydrolysis of α-tricalcium bis(phosphate) in the presence of succinate ions. The organic substance is considered to be introduced into the structure of the hydrolysis product, i.e., octacalcium bis(hydrogen-phosphate) tetrakis(phosphate) pentahydrate, through the replacement of HPO42− by C4H4O42−.
Absolute configurations are assigned to some cationic cis-[Co(diamine)2(X)(Y)]n+-type complexes by detecting the direction of the chiral equilibrium shift induced for [Cr(ox)3]3− in the presence of these chiral complexes in water–dioxane mixtures. The assignments are found all consistent with those made earlier by CD spectra.
Sulfide ion was converted to Methylene Blue through the reaction with N,N-dimethyl-p-phenylenediamine in the presence of iron(III) ion. The dye produced was fixed by batch method onto the coagulated mixture of finely divided anion and cation exchange resins. The coagulated material was collected by filtration on a filter paper as a disk of thin layer, which was then soaked in an acetate buffer solution, and subjected to the spectrophotometric analysis. The calibration graph was linear over the range 1.03–10.3 nmol of sulfide. The method was applied to some hot spring waters.
The reaction of diphenylcyclopropenone with R1N=C(R2)X (2) (R1, R2= alkyl, aryl, X=MeO, EtO, MeS, or Me2N) gave 2-pyrrolin-4-one (3) in good yield. The less reactive carboximidothioate (2, R1=4-MeC6H4, R2=Ph, X=MeS) yielded isomeric 3-pyrrolin-2-one together with 3.
α-Halo derivatives of ketones, ester, and nitrile reacted readily with potassium ethoxythiocarbonylcyanamide to provide the corresponding 4-amino-2-ethoxythiazole compounds in good yields, while α-halo amide did not. In a similar manner, α,α′-dihalo ketone reacted with 2 equiv of alkoxythiocarbonylcyanamide and S-methyl N-cyanocarbamodithioate salts to give the corresponding bis(4-amino-5-thiazolyl) ketones.
A series of five different 2,2-diphenyl-3-oxetanols was synthesized by photocycloaddition of benzophenone and enol trimethylsilyl ethers followed by protolysis of the resultant 3-trimethylsiloxyoxetanes. Thermal cleavage and acid-catalyzed rearrangement of these oxetanes are described.
Nitro-, acyl-, and cyanophenyltributyltin can be prepared by the reaction of hexabutylditin with the corresponding aryl iodide in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium.
Hydrolysis of p-nitrophenyl acetate (PNPA) and p-nitrophenyl hexanoate (PNPH) catalyzed by several linear and cyclic peptides containing histidine and other amino acid residues was studied. The catalytic activity of the peptides was less than that of imidazole for PNPA and PNPH. On the other hand, in the presence of a cationic surfactant and a hydrophobic peptide the hydrolysis of PNPH was significantly enhanced.