Formation of heterocyclic C-60 derivative by gas-phase ion/molecule reaction

Ion/molecule reactions of C-60 with vinyl acetate under chemical ionization conditions have been studied here. Compared with C2H3O+ from acetone, C2H3O+ from vinyl acetate undergoes the reactions more easily, a new heterocycle between C-60 and the studied ion is formed The generation of two sigma-bonds and little angle tensile force of pentatomic ring make it more stable.

Synthesis and characterization of a new double-cubane Mo-Fe-S cluster compound, [NEt(4)](3)[Mo2Fe6S8(mu-OMe)(3)(SPh)(3)Cl-3]

The new double-cubane cluster compound [NEt(4)](3)[Mo2Fe6S8(mu-OMe)(3)(SPh)(3)Cl-3] is synthesized from (NH4)(2)MoS4, FeCl3, Fe powder, S powder, NaSPh and NEt(4)Br in MeOH-DMF, its crystal structure is determined by X-ray crystallography, and results of XPS indicate a valence state of +4 for Mo.

ATTEMPTS TO MODIFY AN ELECTRODE WITH A CONDUCTING PLATINUM CLUSTER COMPOUND

A conducting platinum cluster compound K1.64Pt(C2O4)(2) was electrochemically synthesized on a glassy carbon electrode through the electrooxidation of K2Pt(C2O4)(2) in an aqueous medium using single potential step and cyclic voltammetry methods. The precursor K2Pt(C2O4)(2) was prepared by a ligand exchange reaction between C2O42- and PtCl42-. During single potential step experiments, the electrolytic current corresponding to the oxidation of K2Pt(C2O4)(2) increased dramatically after a sharp decrease at the beginning (due to the formation of conducting K1.64Pt(C2O4)(2) on the surface of the working electrode). Two kinds of mechanism account for the current transients at the different applied potentials. Cyclic voltammetry was conducted with K1.64Pt(C2O4)(2) on the surface of the working electrode and a steady-state diffusion current was observed. Since the material grew in a fibrous manner, each conducting fiber which was in contact with the electrode could serve as an ultramicroelectrode. The behavior of the working electrode was thus changed from a plain to an ultramicroelectrode array.

THE EXTRAORDINARY PROPERTIES OF ELECTROCHEMICALLY SYNTHESIZED CLUSTER COMPOUND K1.64PT(C2O4)2

The conducting platinum cluster compound K1.64Pt(C2O4)2 was electrochemically synthesized on a glassy carbon electrode through electrooxidation of K2Pt(C2O4)2 in an aqueous medium using a single potential step and cyclic voltammetry methods. Two kinds of

CRYSTAL-STRUCTURE AND INFRARED-SPECTRA OF A LANTHANUM COORDINATION COMPOUND WITH GLYCINE, ([LA(GLY)S-CENTER-DOT-2H2O]CENTER-DOT(CLO4)3)N

A lanthanum coordination compound with glycine {[La(Gly)3.2H2O].(ClO4)3}n (Gly = NH+ 3-CH2-COO-) was synthesized and obtained in the form of single crystals. Its X-ray crystal structure has been determined and the IR spectrum has been studied. Crystallo

UNUSUAL VOLTAMMETRIC BEHAVIOR OF AN ELECTROCHEMICALLY SYNTHESIZED CONDUCTING PLATINUM CLUSTER COMPOUND K-1.64[PT(C2O4)(2)]

The compound K-1.64[Pt(C2O4)(2)] was electrochemically synthesized on a glassy carbon electrode using both single-potential step and cyclic voltammetry techniques; voltammetric behaviour of the working electrode was changed dramatically with deposition of

THE CATALYTIC ACTIVITY OF HETEROPOLY ACIDS (SALTS) AND MONO-LACUNARY HETEROPOLY TUNGSTOPHOSPHORIC COMPOUND IN THE OXIDATION OF ALCOHOLS

The catalytic activity of heteropoly compounds in the oxidation of benzyl alcohol and cyclohexa nol under phase transfer conditions has been studied. The catalytic activity of six kinds of heteropoly acids with Keggin structure will drop by the order of GeMo12 (H4GeMo12O40). PW12, PMo12, SiMo12, GeW12 and SiW12. When the three protons of H3PW12O40 Were replaced by Na+ step by step, the catalytic activity will raise gradually with the drop of acidity. The addition of base and trace amount of sulfuric acid to the reaction system resulted in an increase of catalytic activity. It was found that catalytic activity of mono-lacunary heteropoly compounds is higher than that of the primary heteropoly acids (or salts). The catalytic oxidation system of HPA-H2O2-PTC is very active in the oxidation of benzyl alcohol ana cyclohexanol, but it has little activity in the oxidation of inactive compounds such as n(or iso)-proplalcohol. n-butyl alcohol and n-hexanol. Solvent has great effect on reaction, when polar compounds such as water were used as solvent, the catalytic activity is better than that when non-polar compounds were used as solvent.

ELECTROCHEMICAL FORMATION OF NI-Y INTERMETALLIC COMPOUND LAYER IN MOLTEN CHLORIDE

The reduction of Y(III) ions in molten chloride is known to be a one-step three electron reaction [1, 2, 3], but a voltammogram of YCl3 in molten LiCl-KCl-NaCl at a nickel electrode shows at least two reduction peaks of Y(III) ions, indicating the possibility of formation of Ni-Y intermetallic compounds. Using a galvanostatic electrolysis method, samples were prepared at several current densities at 450, 500, 600 and 700-degrees-C, respectively, and were identified with X-ray diffraction (XRD) and electron probe microanalysis (EPMA) methods. The results show that Ni2Y, Ni2Y3 and NiY can be produced by electrolysis and Ni2Y is found to be the predominant Ni-Y intermetallic compound under the experimental conditions. Nickel appears to diffuse in Ni2Y faster than yttrium, and the diffusion process is the rate determining step during Ni2Y formation.

STRUCTURE OF AN ERBIUM COORDINATION COMPOUND WITH L-PROLINE, ([ER(PRO)2(H2O)5]CL3)(N)

catena-Poly[{pentaaqua(L-proline-O)-erbium-mu-(L-proline-O:O')} trichloride], {[Er(C5H9-NO2)2(H2O)5]Cl3}n, M(r) = 594.0, monoclinic, P2(1), a = 8.294 (1), b = 10.981 (3), c = 11.934 (3) angstrom, beta = 107.04 (2)degrees, V = 1039.2 (4) angstrom3, Z = 2, D(x) = 1.90 g cm-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 45.2 cm-1, F(000) = 586, T = 298 K, R = 0.0244 for 1711 unique reflections [I > 3 sigma(I(o))]. The crystal consists of one-dimensional chains of infinite length in which one L-proline ligand bridges two neighboring Er ions, the other L-proline ligand being monodentate.

RAMAN-SPECTROSCOPIC STUDY OF LAYER STRUCTURE COMPOUND [N-CNH2N+1NH3]2ZNCL4

The C-H stretching, C-H bending, C-C stretching and the low-frequency vibration regions have been investigated by Raman spectroscopy for [n-CnH2n+1NH3]2 ZnCl4 with n=7 approximately 12, 16. It is found that their frequency and relative intensities are related to the length of carbon chain in the molecules and present the odd-even effect to carbon atom numbers in chain. Some changes in spectra are interpreted in terms of the different molecular packing and interaction of chain.

AN INFRARED SPECTROSCOPIC STUDY OF THE STRUCTURAL PHASE-TRANSITION IN THE PEROVSKITE-TYPE LAYER COMPOUND [N-C16H33NH3]2COCL4

The solid-solid phase transitions in the perovskite-type layer compound [n- C16H33NH3]2CoCl4 have been studied by infrared spectroscopy. A new phase transition at 340 K was found by comparison with differential scanning calorimetry results. A temperature dependence study of the infrared spectra provides evidence of the occurrence of structural phase transitions related to the dynamics of the alkylammonium ions and hydrogen bonds. The main transition at 374 K corresponds to the conformational order-disorder change in the chain, which probably couples with reorientational motions of the NH3 polar heads. GTG or GTG' defects appear in the high temperature disordered phase.

Novel antifouling and antimicrobial compound from a marine-derived fungus Ampelomyces sp.

In this study, using a bioassay-guided isolation and purification procedure, we obtained 3-chloro-2,5-dihydroxybenzyl alcohol from a marine-derived Ampelomyces species that effectively inhibited larval settlement of the tubeworm Hydroides elegans and of cyprids of the barnacle Balanus amphitrite. The inhibitive effect on larval settlement was nontoxic and the EC50 of 3-chloro-2,5-dihydroxybenzyl alcohol ranged from 3.19 mu g ml(-1) to 3.81 mu g ml(-1) while the LC50 was 266.68 lambda g ml(-1) for B. amphitrite cyprids; EC50 ranged from 0.67 mu g ml(-1) to 0.78 mu g ml(-1), and LC50 was 2.64 mu g ml(-1) for competent larvae of H. elegans, indicating that inhibitive effect of this compound was nontoxic. At a concentration of 50 mu g per disc, this compound showed strong inhibitive effects on the growth of 13 out of 15 marine bacterial species tested in disc diffusion bioassay. Overall, the high inhibitory activities against bacteria and larval settlement as well as the non- or low-toxic nature of this compound to the barnacle and polychaete larvae suggest this compound could be a potent antifoulant and/or antibiotic.

Antimicrobial screening and active compound isolation from marine bacterium NJ6-3-1 associated with the sponge Hymeniacidon perleve

Twenty-nine marine bacterial strains were isolated from the sponge Hymeniacidon perleve at Nanji island, and antimicrobial screening showed that eight strains inhibited the growth of terrestrial microorganisms. The strain NJ6-3-1 with wide antimicrobial spectrum was identified as Pseudoalteromonas piscicida based on its 16S rRNA sequence analysis. The major antimicrobial metabolite, isolated through bioassay-guide fractionation of TLC bioautography overlay assay, was identified as norharman (a beta-carboline alkaloid) by EI-MS and NMR.

Bacterial roles in the formation of high-molecular-weight dissolved organic matter in estuarine and coastal waters: Evidence from lipids and the compound-specific isotopic ratios

High-molecular-weight dissolved organic matter (HMW-DOM, > 1,000 Daltons) is actively involved in the global biogeochemical cycling of many elements, but its carbon sources and detailed formation pathways are still not well understood. In this study, we measured bulk stable carbon and nitrogen isotopic ratios, lipid composition, and compound-specific carbon isotopic ratios of HMW-DOM samples collected from four U.S. estuaries (Boston Harbor/Massachusetts Bay, Delaware/Chesapeake Bay, San Diego Bay, and San Francisco Bay). Analytical results show (1) a fraction of HMW-DOM (lipid associated) in estuarine and coastal waters is derived from bacteria and phytoplankton; (2) this fraction of HMW-DOM is formed by various release processes of bacterial membrane components and bacterial reworking of phytoplankton-derived material; (3) this fraction of HMW-DOM is generally present in all samples from different coastal systems despite variable organic matter inputs and environmental conditions, suggesting an important bacterial role in HMW-DOM formation.

THE COMPOUND EYE AS AN INDICATOR OF AGE AND SHRINKAGE IN ANTARCTIC KRILL

Laboratory studies have shown that Antarctic krill (Euphausia superba) shrink if maintained in conditions of low food availability. Recent studies have also demonstrated that E. superba individuals may be shrinking in the field during winter. If krill shrink during the winter, conclusions reached by length-frequency analysis may be unreliable because smaller animals may not necessarily be younger animals. In this study, the correlation between the body-length and the crystalline cone number of the compound eye was examined. Samples collected in the late summer show an apparent linear relationship between crystalline cone number and body-length. From a laboratory population, it appears that when krill shrink the crystalline cone number remains relatively unchanged. If crystalline cone number is little affected by shrinking, then the crystalline cone number may be a more reliable indicator of age than body-length alone. The ratio of crystalline cone number to body-length offers a method for detecting the effect of shrinking in natural populations of krill. On the basis of the crystalline cone number count, it appears from a field collection in early spring that E. superba do shrink during winter.