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Solubilities of ribidium tetraphenylborate in water, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol and l-octanol at 288.15, 298.15, 308.15, 318.15, 328.15 K have been determined by spectrophotometry. The standard Gibbs energy of transfer of ribidium tetraphenylborate from water to straight-chain n-alkanols and the primary medium effect of rubidium tetraphenylborate from 288.15 to 328.15 K have been calculated. Furthermore, the contribution of microscopic interactions to the standard Gibbs energy of transfer of rubidium tetraphenylborate in calculated and discussed.

The solubilities of o -xylene, m -xylene, and p -xylene in mixed solvents of t -butyl alcohol (TBA) and water at T =(283.15, 288.15, 293.15, and 298.15) K have been determined by spectrophotometry. The mole fractions of TBA in the mixed solvents are x =(0.000, 0.010, 0.020, 0.030, 0.040, 0.045, 0.050, 0.060, 0.080 and 0.100), respectively. The Gibbs energies of hydrophobic interaction (HI) for the aggregating process of two methane molecules with one benzene molecule in the mixed solvents have been studied, and the effects of solvent structure and solutes gathering state on the strength of HI have also been discussed.

Standard Gibbs energies of transfer of potassium tetraphenylborate from water to (water + t -butyl alcohol) (TBA) mixtures at T = 298.15 K have been studied. The mole fractions of TBA in the mixed solvent are 0.00, 0.01, 0.02, 0.03, 0.04, 0.045, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.20, 0.40, 0.60, 0.80, and 1.00, respectively. The primary medium effect of potassium tetraphenylborate in the mixed solvent is discussed.

Barium(II) tetraphenylborate, Ba(Bph4))2·4H2O was prepared, and its decomposition mechanism was studied by means of TG and DTA. The products of thermal decomposition were examined by means of gas chromatography and chemical methods. A kinetic analysis of the first stage of thermal decomposition was made on the basis of TG and DTG curves and kinetic parameters were obtained from an analysis of the TG and DTG curves using integral and differential methods. The most probable kinetic function was suggested by comparison of kinetic parameters. A mathematical expression was derived for the kinetic compensation effect.

Phytochemical investigation of dichloromethane (DCM) extract from the stems of Paragonia pyramidata var. pyramidata L. Rich. (Bur.) resulted in the isolation and characterization of two new triterpenoids 3β,19β-dihydroxylup-12, 20(29)-diene-28-oic acid (1) and 3β,19β-dihydroxylup-12-en-28-oic acid (2), three known triterpenoids lupeol (3), spinosic acid A (4) and oleanolic acid (5), together with four known steroids (20R)-22E-24-ethylcholesta-4,22-dien-3-one (6), (20R)-24-ethylcholest-4-en-3-one (7), stigmasterol (8) and β-sitosterol (9). HREIMS, GCMS and NMR experiments including HSQC, HMBC, COSY and NOESY were used for the determination of the structures and NMR spectral assignments. This is the first report about the chemical constituents for this plant.

We report an improvement to the lateral-magnetic-tweezers which can be used to stretch and twist DNA molecules, and to probe the interaction between DNA and proteins. The apparatus enables not only direct measurement of the extension and rotation of DNA but also easy refreshing of the buffer in the flow chamber. With this apparatus, the experimental efficiency can be greatly improved by manipulating several DNA molecules simultaneously. The force exerted on DNA molecules ranges from 0.1 to 40pN, satisfying the requirement of most single molecule experiments. To demonstrate the applicability of the apparatus, we measured the extension-force curve and the extension-rotation curve of DNA and studied the translocation of DNA by a motor protein. The results agree well with those reported in the literature.