BEHAVIOUR OF α-NITROSO-β-NAPHTHOL IN HEMATITE FLOTATION

Based on theoretical calculation of electronegativity of groups of flotation reagent and method of infrared adsorption spectroscopy,the collection and adsorption of α-nitroso-β- naphthol in hematite flotation have been studied.The chemical adsorption seems to be predominant owing to formation of pentacyclic nitrosyl chelate compound by atoms of nitrosyl bond in α-nitroso-β-naphthol together with Fe(Ⅲ)on hematite surface.Mean- while,the nonuniform multilayer physical adsorption is also occurred.

Solid-Liquid Extraction of Some Lanthanide Complexes with 1-Nitroso-2-Naphthol

The extraction behavior of Sm(III), Eu(III),Er(III) and Yb(III) with 1- nitroso -2-naphthol (HA) in paraffin has been studied. The composition of,extracted complexes has been determined to be LnA(3) by slope analysis method. The effect of temperature on extraction system is also investigated and thermodynamic parameters are obtained.

Synergistic Extraction of Lanthanides by 1-Nitroso-2-Naphthol and Trioctylphosphine Oxide in Paraffin Wax

The paraffin wax was used as a diluent for 1-nitroso-2-naphthol(HA) and trioctylphosphine oxide(TOPO) in the extraction of lanthanides at 70℃. The composition of the extracted species was given as LnA_3(TOPO)_2 by means of the slope analysis. The variation of the synergistic extraction equilibrium constant(K_ sex) was investigated at 60～80℃, and the thermodynamic data were calculated. The dependence of separation factors on temperature was also studied.

Cobalt Determination by Means of Flow Injection On-line Sorbent Preconcentration-Flame Atomic Absorption Spectrometry with 1-Nitroso-2-naphthol as a Complexing Reagent

The suitability of 1-nitroso-2-naphthol(NN) as a complexing agent for on-line preconcentration of cobalt eluted on the C_(18) microcolumn by means of the FI-FAAS system was tested. Various parameters affecting the complex formation and its elution were optimized. A 2.3×10^(-3) mol/L reagent solution and the aqueous sample solution acidified with 0.1% (volume fraction) nitric acid were on-line mixed (6.4 mL/min) on a reaction coil set at (65±1)℃ and flowed through the microcolumn for 30 s. The pH of the mixed solution was adjusted to 3—4 with HNO_3(1 mol/L) or NaOH(1 mol/L). The adsorbed complexes in the microcolumn were eluted into the nebulizer of FAAS in 10 s with ethanol acidified with 1% HNO_3(3.0 mL/min). A good precision(1.6% for 100μg/L Co(Ⅱ), n=10), a high enrichment factor 17.2, with detection limit (3σ) 3.2μg/L, and sample throughput (90 h^(-1)) were obtained. The method was applied to the certified reference materials(CRMs), NBS-362 and NBS-364, for the determination of cobalt and the results were in good agreement with the certified values.

Biodegradation of 2-naphthol and its metabolites by coupling Aspergillus niger with Bacillus subtilis

To explore biodegradation of 2-naphthol and its metabolites accumulated in wastewater treatment,a series of bio-degradation experiments were conducted.Two main metabolites of 2-naphthol,1,2-naphthalene-diol and 1,2-naphthoquinone,were identified by high-performance liquid chromatography with standards.Combining fungus Aspergillus niger with bacterium Bacillus subtilis in the treatment enhanced 2-naphthol degradation efficiency,lowered the accumulation of the two toxic metabolites.There were two main phases during the degradation process by the kinetic analysis：2-naphthol was first partly degraded by the fungus,producing labile and easily accumulated metabolites,and then the metabolites were mainly degraded by the bacterium,attested by the degradation processes of 1,2-naphthalene-diol and 1,2-naphthoquinone as sole source of carbon and energy.Sodium succinate,as a co-metabolic substrate,was the most suitable compound for the continuous degradation.The optimum concentration of 2-naphthol was 50 mg/L.The overall 2-naphthol degradation rate was 92%,and the COD Cr removal rate was 80% on day 10.These results indicated that high degradation rate of 2-naphthol should not be considered as the sole desirable criterion for the bioremediation of 2-naphtholcontaminated soils/wastewater.

Sorption of 1-naphthol by plant cuticular fractions

The contribution of aliphatic-rich plant biopolymer to sorption of hydrophobic organic compounds is significantly important because of their preservation and accumulation in the soil environment, but sorption mechanism is still not fully understood. In this study, sorption of 1-naphthol by plant cuticular fractions was examined to better understand the contributions of respective fraction. Toward this end, cuticular materials were isolated from the fruits of tomato by chemical method. The tomato cuticle sheet consisted of waxes （6.5 wt%）, cuticular monomer （69.5 wt%）, and polysaccharide （24.0 wt%）. Isotherms of 1-naphthol to the cuticular fractions were nonlinear （N value （0.82 - 0.90）） at the whole tested concentration ranges. The K∞/Kow ratios for bulk cuticle （TC1）, dewaxed cuticle （TC2）, cutin （TC4）, and desugared cuticle （TC5） were larger than unity, suggested that tomato bulk cuticle and cutin are much powerful sorption medium. Sorption capability of cutin （TC4） was 2.4 times higher than the nonsaponifiable fraction （TC3）. The 1-naphthol interactions with tomato cuticular materials were governed by both hydrophobic-type interactions and polar （H-bonding） interactions. Removal of the wax and polysaccharide materials from the bulk tomato cuticle caused a significant increase in the sorption ability of the cuticular material. There was a linear negative trend between K∞ values and the amount of polysaccharides or fraction＇s polarities （（N＋O）/C）; while a linear positive relationship between K∞ values and the content ofcutin monomer （linear R^2 = 0.993） was observed for present in the cuticular fractions. Predominant sorbent of the hydrophobic organic compounds （HOCs） in the plant cuticular fraction was the cutin monomer, contributing to 91.7% of the total sorption of tomato bulk cuticle.

Synthesis of 1,1'-binaphthyl-2,2'-diamine from 2-naphthol under atmospheric pressure

A practical protocol to obtain 1,1′-binaphthyl-2,2′-diamine was developed from 2-naphthol and 2-naphthylhydrazine under mild conditions： solvent-free, 125-130 ℃, atmospheric pressure. The convenient procedure makes the process amenable for large-scale synthesis of the versatile compound.

Effects of the surface chemistry of macroreticular adsorbents on the adsorption of 1-naphthol/1-naphthylamine mixtures from water

The adsorption behaviors of 1-naphthol, 1-naphthylamine and l-naphthol/l-naphthylamine mixtures in water over two macroreticular adsorbents were investigated in single or binary batch systems at 293 K, 303 K and 313 K respectively. All the adsorption isotherms in the studied systems can be adequately fitted by Langmuir model. In the case of aminated macroreticular adsorbent NDA103, 1-naphthol is adsorbed to a larger extent than 1-naphthylamine; while, the opposite trend is found for nonpolar macroreticular adsorbent NDA100. It is noteworthy that at higher temperature（303 K and 313 K）, the total uptake amounts of 1-naphthol and 1-naphthylamine in all binary-component systems are obvious larger than the pure uptake amounts in single-component systems, which is presumably due to the cooperative effect primarily arisen from the hydrogen-bonding interaction between the loaded 1-naphthol and 1-naphthylamine molecules. The simultaneous adsorption systems were confirmed to be helpful to the selective adsorption towards 1-naphthol according to the larger selective index.

ADSORPTION OF LATERALLY INTERACTING 1-NAPHTHOL/1-NAPHTHYL-AMINE MIXTURES ON NONPOLAR SURFACES FROM AQUEOUS SOLUTIONS

The binary adsorption behavior of 1-naphthol/1-naphthylamine mixtures in water on nonpolar adsorbent Amberlite XAD4 was investigated at 293 K, 303 K and 313 K, respectively. The experimental uptakes of 1-naphthol and 1-naphthylamine in all binary-component systems of different molar ratios were obviously higher than the corresponding uptakes predicted by the extended Langmuir model, assuming no interaction between the adsorbed molecules of the two components. This phenomenon was attributed to the cooperative adsorption effect arising from the hydrogen bonding interaction between 1-naphthol and 1-naphthylamine molecules. A modified extended Langmuir model was proposed to describe the binary adsorption behavior by means of introducing a fitting parameter related with the cooperative adsorption effect of the adsorbates.

Improved Studies on the Synthesis,Characterization and Crystal Structure of 2,2-Dimethyl-5-nitro-5-nitroso-1,3-dioxane

The synthetic process for 2,2-dimethyl-5-nitro-5-nitroso-1,3-dioxane（DMNNDO） was improved by using tri（hydroxymethyl）nitromethane and acetone as starting materials through a ＂one-pot＂ method combined with alkaline hydrolysis and nitrosation reactions. The yield of DMNNDO was increased from 37% to 45%. The structure of DMNNDO was characterized by IR,^1H NMR,^13 C NMR,and elemental analysis. Also the thermal decomposition of DMNNDO was studied by using DSC and TG-DTG to find that there are primarily two exothermic decomposition processes between 90 and 300 oC. The crystal structure of DMNNDO was studied by X-ray single-crystal diffraction for the first time. The molecular structure exists as a dimeric form due to the presence of nitroso group. The crystal belongs to monoclinic system,space group C2/c with a = 14.515（3）,b = 9.955（2）,c = 11.897（2） °,β = 98.500（3）°,V = 1.6998（2） nm^3,Z = 8,D_c = 1.486 g×cm^-3,μ = 0.128 mm^-1,F（000） = 800,S = 1.055,R = 0.0358 and wR = 0.0917. In particular,DMNNDO could be easily hydrolyzed in hydrous systems and the hydrolysis mechanism in CDCl_3 was revealed by means of NMR monitoring.

Synthesis and Characterization of Nitrosonaphthol Dyes Based on 1-Naphthol and Their Dyeing Properties on Tanned Leather

Nitrosonaphthol dyes and other corresponding analogues were synthesised from 1-Naphthol. The dyes were applied onto chrome and vegetable tanned leather upon characterization. The results indicate that the dye bath exhaustion was better on chrome tanned leather than on vegetable tanned leather. This may be attributed to the chelating effect of chrome on leather and the higher temperature of dyeing the chrome tanned leather compared with the vegetable tanned leather. The fastness properties of the dyes of washing ranging from (3 - 5), perspiration on acid (4 - 5), alkaline (4 - 5) and light (4 - 7) were impressive on both vegetable and chrome tanned leather respectively.

SOLVENTLESS CYCLOCONDENSATIONS BETWEEN 1-NAPHTHOL AND BENZILS

In the absence of organic solvents,the Lewis acid catalyzed cyclocondensation reactions between 1-naphthol and benzils gave 3-aryl-3-aryl'naphtho[1,2-b]furan-2(3H)-ones(NFs) in good yields(62%～70%)An electrophilic substitution mechanism involving formation of n-EPD/v- EPA complexes and rearrangement of aryl group was proposed.

A Convenient Preparation of Enantiopure 1,1'-bi-2-naphthols via an Inclusion Complexation in the Solid State

Inclusion reaction of reaction 1, 1'-bi-2-naphthol and (S)-proline was examined uuder the solid state and the solid-liquid conditions. The results indicated that a solid mixture of racemic 1, 1'-bi-2-naphthol and (S)-proline in a 1 : 1 molar ratio was kept at 50-80 for 3-4 h, followed by treatment with benzene to give an insoluble solid and a benzene solution, from which (S)- (- )- and (R)-(+)-1, 1'-bi-2-naphthols of a modest level or optical purity were obtained. Arter 'kinetic' crystallization, both essentially enantiopure iso- mers were provided in 15%-35 % overall yields ,respectively.

Effects of 1-Naphthol on Physiological Parameters of Chlorella vulgaris

[ Objective] This study aimed to investigate the effects of 1-naphthol on primary productivity in aquatic ecosystems. [ Method] The effects of 1-naphthol on biomass, chlorophyll a content, malondialdehyde （MDA） content and soluble protein content of Chlorella vulgaris were investigated. [ Result] 1-Naphthol could significantly inhibit the growth of Chlorella vulgaris. On the 7^th d, the biomass of Chlorella vulgaris exposed to 1.0, 3.0, 6.0, 12.0 and 18.0 mg/L 1-naphthol was 60.26%, 48.15%, 41.32%, 28.59% and 27.10% of that in control respectively, exhibiting a significant dose-response relationship. Chlorella vulgaris was exposed to different concentrations of 1-naphthol （0, 1,5 and 10 mg/L） for 7 d ; with the increase of 1-naphthol concentration, chlorophyll a content of Ch/orella vulgaris was reduced, MDA content increased gradually, soluble protein content increased first and then declined. [ Conclusion] According to the experimental results, 1-naphthol can significantly inhibit the growth of Chlorella vulgaris, thus reducing primary productivity in aquatic ecosystems.

Design and synthesis of chiral Ti-1,1′-bi-2-naphthol coordination polymers for heterogeneous catalytic asymmetric oxidation of sulfides

Polymer-immobilized catalysis has many advantages such as easy recovery and reuse of catalyst. We prepared three novel chiral 1,1＇-bi-2-naphthol-Ti coordination polymers with properly designed ligands and Ti（O^ipr）4 under mild conditions. The prepared polymers exhibited good activity and excellent enantioselectivity （over 99%ee） in catalyzing the asymmetric oxidation of sulfides. The bridge linker in the polymer and the reaction solvent noticeably affected the enantioseleetivity. The chiral coordination polymer was very stable and easy to separate from catalyzed reaction systems, with no significant loss of activity or enantioselectivity after reuse for at least ten times. These findings suggest a promising type of catalysts for synthesizing the widely used sulfoxides by asymmetrically oxidizing sulfides.

New Method for Preparation of 1-Amidoalkyl-2-Naphthols via Multicomponent Condensation Reaction Utilizing Tetrachlorosilane under Solvent Free Conditions

An efficient and direct procedure for the synthesis of amidoalkylnaphthol derivatives employing a multi-component and one-pot condensation reaction of 2-naphthol, aromatic aldehyde and ace-tonitrile in the presence of tetrachlorosilane (TCS). A binary reagent from (TCS)/ZnCl2 was used upon applying benzonitrile.

Environmentally Benign Synthetic Protocol for O-Alkylation of <i>β</i>-Naphthols and Hydroxy Pyridines in Aqueous Micellar Media

Ultrasonic and microwave-assisted practical methods have been developed for the O-alkylation of aryl (β-naphthols) and Heteroaryl (hydroxy pyridines) in aqueous surfactant media in good to excellent yields. The developed methods are simple, efficient, economical and environmentally safe. Our novel methods describe a set of green methods to Wil-liamson synthesis.