The concentration dependence of fluidities and conductances of molten calcium nitrate tetrahydrate–MNCS (M=Na+ or NH4+) systems was quantitatively explained by the isoenergetic and isoentropic equations essentially based on the Vogel-Tammann-Fulcher (VTF) and the Configurational Entropy Model (CEM) equations. The pre-exponential terms of the VTF and the Doolittle’s equations were found to depend linearly on the values of the corresponding parameters, i.e., T0 the zero mobility temperature and those of V0, the molar intrinsic volume at T0, respectively. The linear interdependence of the two thermodynamic parameters, T0 and V0 on each other has been demonstrated. In addition to the linear dependence of the corrected energy of activation, Ecor on V0, a physically meaningful linear dependence of Ecor on T0 has also been demonstrated.
Uranium has been quantitatively extracted into IBMK from ≈2.2 mol dm−3 aluminium nitrate solution at pH 0.8–0.9. Coextracted thorium (≈10%) is returned to the aqueous phase by addition of benzene. Subsequently, thorium is extracted into IBMK in the presence of hexadecyltrimethylammonium bromide (CTAB). This separation method has been applied to the analysis of uranium and thorium content of monazite sand.
A method is described for the determination of molybdenum based on reaction with potassium thiocyanate and Rhodamine 6G in 0.55–0.8 mol dm−3 hydrochloric acid medium. The method is sensitive (ε=2.63×105 l mol−1 cm−1) and obeys Beer’s law over the range 0.04–0.24 ppm of molybdenum. Selectivity can be considerably improved by collecting molybdenum on iron (III) hydroxide. In conjunction with the collection procedure, the method is useful to determine as low as 5 ppb of molybdenum present in 100 cm3 of aqueous samples.
A detailed investigation of the ion exchange processes of silver and thallium(I) ions on α-Zr(HPO4)2·H2O has been carried out. The H+/Ag+ exchange occurs in AgNO3 or CH3COOAg solution with a single phase transition and leads to Zr(AgPO4)2·H2O (interlayer distance 8.4 Å). The H+/Tl+ ion exchange process has been performed by titrating the exchanger with 0.1 M (TlNO3+TlOH) solution, owing to the great ionic size of Tl(I). The titration curve shows essentially a single plateau. In a similar way to that for H+/Ag+ exchange, the process takes place with a single phase transition, leading to Zr(TlPO4)2·H2O (interlayer distance 9.0 Å). Since the processes are new examples in which a univalent cation is exchanged with a single phase transition in α-Zr(HPO4)2·H2O, the so called “polyfunctionality” of this exchanger has been discussed, considering the high polarizability of Ag+ and Tl+ ions. The catalytic potential applications of zirconium phosphate loaded with Ag+ ions are outlined.
Synthesis of some 2,3-disubstituted 6-bromo-4(3H)-quinazolinones is described. Treatment of some 4-quinazolinones with phosphorus pentasulfide gave the corresponding 4-quinazolinethiones. The reaction of 6-bromo-2-methyl-3,1-benzoxazin-4-one with hydroxylamine hydrochloride gave 6-bromo-3-hydroxy-2-methyl4(3H)-quinazolinone which on treatment with alkyl halides, acyl chlorides and sulfonyl chlorides gave the corresponding ethers, esters, and sulfonates respectively. 2-Styryl-4(3H)-quinazolinone derivatives are obtained by condensation of aromatic aldehydes and corresponding 3-substituted-6-bromo-2-methyl-4(3H)-quinazolinones. Their antibacterial affinities are of considerable efficiency.
The overall extraction equilibrium constants (Kex) for 1: 1: 1 complexes of 12-crown-4 (12C4) with alkali metal picrates between benzene and water have been determined at 25 °C. The Kex series for the 12C4 for the alkali metal ions are given by Na+>Li+>K+>Rb+≥Cs+.
In the ESR spectra of N,N-bis(phenylthio)-, N,N-bis(phenyl-d5-thio)-, and N,N-bis(3,5-dichlorophenylthio)aminyls, 33S hyperfine splittings were detected. The spin densities in the aminyls were calculated by using the HMO calculations with and without McLachlan’s correction, and the results were compared with the values derived from the 1H, 14N, and 33S hyperfine splittings by use of the relationship a=Qρ.
Phenothiazine forms not only simple cation radical salt of Phenothiazine+· Br− but also complex salt of (Phenothiazine)2+· Br−. In this paper, less-than-half occupied Hubbard model was applied to the complex salt in order to explain its crystal electronic state.
Angular dependence of the fluorescence polarization spectra of anthracene was investigated in polyethylene films using a sample rotation technique. An important role of a nontotally symmetric vibration, the b3g ring vibration at 1655 cm−1, was further confirmed by a combination of this technique and the modulation polarization technique developed previously.
The oxidation of 2-propanol and acetone on ZnO has been studied by IR spectroscopy. Surface isopropoxide was oxidized to acetate and formate ions via enolate complex of acetone. Formation of α-diketone-like species was proposed for oxidation with dinitrogen oxide.
Two pairs of tri- and divalent complex cations [Co(en)3]3+, [Ni(en)3]2+ and [Co(phen)3]3+, [Fe(phen)3]2+ were chromatographed through the SP-Sephadex cation-exchange column using various concentrations of aqueous KBr and K2SO4 solutions as eluent, and the inversion of the elution order was observed for the pair of the phen complexes when eluted with KBr and for that of the en complexes when eluted with K2SO4.
Relative reactivities of N-t-butoxycarbonyl(Boc)amino acids (Gly, Val, Ile, Leu, Tyr, and Phe) and Boc-oligopeptide acids having various numbers of amino acid residues (n=2, 4, 5, 8, and 10) were determined by competitive esterification in reaction with chloromethylated polystyrene. Increase of peptide-chain lengths reduced reactivity of C-terminal carboxylates.
The ozonation of the O-methyloximes has been investigated. Besides the corresponding ketones, ketone diperoxides, and N-methoxyamides were produced. The stereochemistry of the ketone diperoxides was studied by the NMR technique.
We inveatigated the oxidation of thujopsene with lead tetraacetate. In the hydrolysis product, two new sesquiterpenoids were found to be afforded: 6α,10,10-trimethyl-4β-acetyltricyclo[4.4.0.01,3]decane and its C(4)-stereoisomer.
The first anodic peak potentials Epa(O1) for sixteen [2.2]metacyclophanes were surveyed in order to correlate the peak potential with the number and position of the alkyl groups. The analysis of the data gives the additivity parameters, which call for cathodic shifts of 0.14 and 0.035 V per methyl group for R2 or R5 (5- or 13-position) and for substitution at the rest of the positions respectively. The controlled-potential electrolysis of the representative metacyclophanes gave excellent yields of the corresponding tetrahydropyrenes.
Naphthyl benzoates and phenylnaphthalenes were produced, on naphthalene-sensitized photolysis of dibenzoyl peroxide, in different distribution of their isomers from its thermolysis in the presence of naphthalene, suggesting that naphthalene as sensitizer interacts with dibenzoyl peroxide in a specific orientation in the sensitization process.
The blue colored 1-benzothiopyrylium perchlorates were synthesized by the reduction of thiocoumarins with lithium aluminium hydride followed by the treatment with acid. A number of new thiocarbonyl derivatives of thiocoumarins and thiochromones were also synthesized, the spectral characterization of which has been described.
The stoichiometry for the chlorosulfuric acid promoted α-halogenation and the role of fuming sulfuric acid instead of chlorosulfuric acid have been studied. In the α-bromination with molecular bromine, 1 mol of halogen afforded 2 mol of aliphatic α-bromo acid just as the α-iodination, but it is different from α-chlorination which affords only 1 mol of α-chloro acid. Fuming sulfuric acid instead of chlorosulfuric acid was found to be effective for α-bromination, but the yield was lower, while no α-iodination was observed with fuming sulfuric acid.
Irradiation of peracetic acid in isopropylbenzene with 254 nm and over 290 nm lights gave as aromatic products mainly t-butylbenzene, 2-phenyl-2-propanol, and 2,3-dimethyl-2,3-diphenylbutane. The yield of t-butylbenzene was higher in 254 nm photolysis than that with >290 nm, while the yield of hydroxylated aromatics, i. e., 2-phenyl-2-propanol, was much higher with >290 nm than that with 254 nm. The distribution of products was little affected by the intensity of light. These results are discussed by a mechanism involving radicals of different reactivity derived from peracetic acid decomposition.
Reaction of phenacyltriphenylarsonium bromide with N-methylaniline furnished 2-phenylindole predominantly together with 1-methyl-2-phenylindole. The corresponding reaction of the arsonium salt with N,N-dimethylaniline did not give any indole, instead a simple nucleophilic substituted product, α-4′-(dimethylamino)deoxybenzoin was obtained. But, the latter reaction on being carried out in presence of hydrobromic acid afforded 1-methyl-2-phenylindole by the demethylation of N,N-dimethylaniline.