Retention properties of acetone-water mobile phases on a biphenylsiloxane-bonded silica stationary phase in reversed-phase liquid chromatography

The solvation parameter model system constants and retention factors were used to interpret retention properties of 39 calibration compounds on a biphenylsiloxane-bonded stationary phase (Kinetex biphenyl) for acetone-water binary mobile phase systems containing 30–70% v/v. Variation in system constants, phase ratios, and retention factors of acetone-water binary mobile phases systems were compared with more commonly used acetonitrile and methanol mobile phase systems. Retention properties of acetone mobile phases on a Kinetex biphenyl column were more similar to that of acetonitrile than methanol mobile phases except with respect to selectivity equivalency. Importantly, selectivity differences arising between acetone and acetonitrile systems (the lower hydrogen-bond basicity of acetone-water mobile phases and differences in hydrogen-bond acidity, cavity formation and dispersion interactions) could be exploited in reversed-phase liquid chromatography method development on a Kinetex biphenyl stationary phase.     

Excellent acetone sensing properties of porous ZnO

Porous Zn O was obtained by hydrothermal method.The results of scanning electron microscope revealed the porous structure in the as-prepared materials.The acetone sensing test results of porous Zn O show that porous Zn O possesses excellent acetone gas sensing properties.The response is 35.5 at the optimum operating temperature of 320?C to 100 ppm acetone.The response and recovery times to 50 ppm acetone are 2 s and 8 s,respectively.The lowest detecting limit to acetone is 0.25 ppm,and the response value is 3.8.Moreover,the sensors also exhibit excellent selectivity and long-time stability to acetone.     

Fused sulfur-containing pyridine systems. 1. Synthesis and structures of tetrahydropyridothienopyridinone and tetrahydropyridothiopyranopyridinone derivatives

The reactions of N-methylmorpholinium 4-aryl(hetaryl)-5-cyano-2-oxo-1,2,3,4-tetrahydropyridine-6-thiolates with malononitrile and acetone in ethanol afforded substituted tetrahydropyridothienopyridinones. In the absence of acetone, tetrahydropyridothiopyranopyridinones were isolated as the major reaction products. The latter were also synthesized independently by the reactions of the above-mentioned thiolates with 2-amino-1,1,3-tricyanopropene. The structure of 2,4-diamino-10-(2-chlorophenyl)-3-cyano-5-imino-8-oxo-7,8,9,10-tetrahydro-5H-pyrido[2",3":2,3]thiopyrano[4,5-b]pyridine was established by X-ray diffraction analysis.     

Structural study of the 1:1 clathrate of an asymmetric calix[4]arene and acetone

The crystal and molecular structure of the 1:1 clathrate of the asymmetric calix[4]arene,1, and acetone has been determined by X-ray analysis. The crystal data are: tetragonal, space groupP4/n,a=b=12.574(6),c=12.572(6) Å,V=1988(2) ų,Z=2,D _x =1.111 g cm^–3,D _m =1.108 g cm^–3. Least-squares refinement based on 1131 observed reflections withF ₀>3(F ₀) and anisotropic temperature factors led toR=0.096. In spite of the molecular asymmetric calixarene1 the crystal structure has high symmetry, because a part of the host and guest molecules are in disordered states.     

Spectrophotometric study of acid-base equilibria of 4-(2-benzothiazolylazo)resorcinol and 4-(2-benzothiazolylazo)salicylic acid in water-organic solvent media

The visible absorption spectra of 4-(2-benzothiazolylazo)resorcinol (BTAR) and 4-(2-benzothiazolylazo)salicylic acid (BTAS) have been recorded in water-organic solvent mixtures in the pH range 0.5–12.0. The organic solvents used are methanol, ethanol,n-propanol, iso-propanol, acetone, dioxane and dimethyl formamide. The spectral changes have been explained in terms of shifts in equilibria among different molecular and ionic species of BTAR and BTAS existing in solution. The pK _a values corresponding to the different ionization steps have been determined at 25°C and I=0.1M (KNO₃) by graphic analysis of the absorbance-pH curves. The results obtained are discussed in terms of the molecular structure of the reagents and the nature of the organic co-solvent used.     

Acidity function scale for H2SO4 solutions in phenol-acetone solvents with low water content at 25°C

The indicator method was employed to measure the acidity function H ₀ ^S of H₂SO₄ solutions in solvents consisting of an equimolar mixture of phenol and acetone with 0.8% water (from 3.6·10^–4 to 2.6·10^–2 M H₂SO₄) and 2.5% water (from 4.3·10^–4 to 0.32 M H₂SO₄) and of phenol and acetone in a molar ratio of 1:1.5 with 0.67% water (from 1.63·10^–4 to 7.77·10^–2 M H₂SO₄) and 2.09% water (from 4.49·10^–4 to 0.35 M H₂SO₄) at 25°C. The indicators employed were 4- and 2-nitroaniline.Deceased.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Lenneftekhim Scientific-Commercial Association, St. Petersburg. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 72–78, January, 1992.     

Syntheses of Heterocycles from the Sodium Salts of 3-(1-Adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-Adamantyl)-1-hydroxy-1-buten-3-one

The interaction of the sodium salts of 3-(1-adamantyl)-1-hydroxy-1-propen-3-one and 4-(1-adamantyl)-1-hydroxy-1-buten-3-one with hydroxylamine, hydrazine, and guanidine leads to the synthesis of 5-(1-adamantyl)-5-hydroxy- and 5-(1-adamantylmethyl)-5-hydroxy-2-isoxazolines, 3-(1-adamantyl)- and 3-(1-adamantylmethyl)pyrazoles, 3-(1-adamantyl)-2-phenylpyrazole, and 4-(1-adamantyl)-2-amino- and 4-(1-adamantylmethyl)-2-aminopyrimidines.     

Reactions of 9,10-phenanthrenequinone and its nitro derivatives with acetone in the presence of Al2O3

The addition of acetone to 9,10-phenanthrenequinone and 2-nitro-, 2,7-dinitro-, and 2,4,7-trinitro-9,10-phenanthrenequinones in the presence of Al₂O₃ affords mono- and bisadducts. The crystal structures of 10-hydroxy-10-(2-oxopropyl)-2-nitro-9,10-dihydrophenanthren-9-one and 9,10:10,9-bishemiketal of 9,10-dihydroxy-2-nitro-9,10-bis(2-oxopropyl)-9,10-dihydrophenanthrene were determined.