Cation exchange properties of tetratitanic acid with interlayer protons were measured and compared to those of titania with surface hydroxyl protons using the Frumkin equation. Tetratitanic acid showed larger ion-exchange capacity and much higher activity than titania. The characteristics of exchangeable protons and intercalated cations are discussed to explain the different ion-exchange proper...

Pulsed corona discharge has been found to be an effective method for the removal of trichloroethylene (TCE) from the aqueous phase. Almost complete degradation over one hour was observed irrespective of the electrolyte used in the solution. The degradation rates observed in these experiments are higher than those for other organic compounds such as phenol in pulsed corona reactors, thereby sugg...

Interaction of alkaline earth metal (magnesium, calcium, strontium and barium) ions with acetic and lactic acid in aqueous media was investigated by C NMR spectroscopy. In the acetate systems, signals whose chemical shifts were the averages of those of the free and bound acetate ions were observed. Downfield shifts of the carboxylate carbon signals with increasing metal ion concentration indica...

Theoretical self-consistent field molecular orbital calculations indicate that the hydroxyguanidinium ion can dissociate in alkaline or neutral medium by the loss of the hydroxyl proton, leading to the formation of a strong nucleophilic agent which can attack a positive receptor in enzymes, acting in this way as an antitumor and an antiviral agent. Geometry optimization, total energies, and net...

A successful strategy for the enantioselective synthesis of the natural stereoisomer of Taxol (1) has been developed. This strategy utilized the convergent assembly of Taxol's central eight-membered B ring from preformed synthons for rings A (10) and C (9) followed by late introduction of the D ring and side chain. Degradative studies conf i ied the viability of certain crucial manipulations in...

The redox cycle of 2,5-dimethoxybenzoquinone (2,5-DMBQ) is proposed as a source of reducing equivalent for the regeneration of Fe2+ and H2O2 in brown rot fungal decay of wood. Oxalate has also been proposed to be the physiological iron reductant. We characterized the effect of pH and oxalate on the 2,5-DMBQ-driven Fenton chemistry and on Fe3+ reduction and oxidation. Hydroxyl radical formation ...

Steroidal allylic alcohols formed Na+ adduct ion peaks [M+Na]+ by the addition of NaCl in FAB mass spectrometry. A comparison of the intensities of the adduct ion peaks of allylic alcohols with those of the corresponding saturated alcohols and olefin suggested that the olefinic double bond and the proximal hydroxyl group had coordinated to Na+. The adduct ion was stable and did not undergo dehy...

In the mononuclear title compound, [Ag(NO3)(C6H6N2O)2], the Ag(I) atom is located on a twofold rotation axis and the nitrate-chelated Ag(I) atom is further coordinated by two aromatic N atoms of hydroxyl-amine ligands in a distorted tetra-hedral geometry. In the crystal, the nitrate ion has 2 symmetry with the N atom and one O atom located on the twofold rotation axis, and is linked to hy-droxy...