Studies on a Cationically Modified Quaternary Ammonium Salt of Lignin

A new quaternary ammonium salt monomer was synthesized and a quaternary amination of lignin(noted as QL),with the monomer was carried out by grafting copolymerization.The products were characterized by Fourier Transform Infrared spectroscopy(FTIR).The experimental results indicate that the yield of the monomer was 99.06%,and the conversion of the monomer and the grafting yield of QL were 93.69% and 185.78%,respectively.The feasibility of QL as the flocculant to be applied in color removal of five artificial dyes,eriochrome black T(dye A),gongo red(dye B),direct fast black G(dye C),cuprofix blue green B(dye D),and acid black ATT(dye E)was examined.Results show that QL exhibits the favorable flocculation performance and high stability.     

Copolymerization of Chloroprene with Methyl Methacrylate by the EtnAICI3.n (n=1, 1.5, 2)-Vanadium Compound System

Abstract

The copolymerization of chloroprene with methyl methacrylate was studied in the presence of Et_n A1C1_3-n (n=1, 1.5, 2)-vanadium compounds. Monomer reactivity ratios in various catalyst concentrations were compared with that of a usual radical initiator. The apparent monomer reactivity ratio changed with the concentration of alkylaluminum halide. In this polymerization, alternating copolymer could not be prepared by the ordinary catalyst concentration by which the alternating copolymerization of chloroprene with acrylonitrile was carried out. The addition of more than 10 mole % of the alkylaluminum halide based on two monomers was required to prepare the copolymer which had equimolar composition irrespective of the feed monomer ratio.

The configuration in the repeating unit of the copolymer was discussed by comparison with the NMR and IR spectra of the radical copolymer and the cyclic Diels-Alder adduct of chloroprene-methyl methacrylate. The high alternating tendency was clarified by ozonolysis of the copolymer which was prepared under the conditions which produced equimolar copolymer in various feed monomer ratios. The chloroprene unit of the copolymer was present in the 1, 4-trans structure in the copolymer prepared by the Et_n A1C1_3-n -vanadium compound system.     

新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯的合成及与季铵盐型阳离子表面活性剂的显色反应

合成了新试剂1-(2-羟基-3,5-二硝基苯基)-3-[4(苯基偶氮)苯基]-三氮烯(HDNPAPT),研究了该试剂在NaOH介质中与阳离子表面活性剂漠化十六烷基三甲铵(CTMAB)、溴化十六烷基吡啶(CPB)、溴化十二烷基二苄铰(DDMBAB)形成1:3的紫红色离子缔合物显色体系.测定了显色体系表面活性剂的临界胶束浓度、表观摩尔吸光系数ε_(max)、符合比尔定律的范围.探讨了微量阳离子表面活性剂CMTAB、CPB和DDMBAB的测定方法,结果满意.     

Preparation of light-stable micelles with azo dyes from a nonamphiphilic random block copolymer

Light-stable micelles with azo dyes were prepared by micelle formation of a nonamphiphilic diblock copolymer containing azobenzene and UV absorbent at ca. 1 mol% as the unit ratios. The nonamphiphilic block copolymer consists of two different kinds of random copolymer blocks: poly[4-(phenylazophenoxymethyl)styrene-co-vinylphenol] (P(AS-co-VPh)) and poly[4-(2-hydroxybenzophenoxymethyl)styrene-co-styrene] (P(HBS-co-St)). This random block copolymer, P(AS-co-VPh)-b-P(HBS-co-St) formed the micelles in the presence of 1,4-butanediamine (BDA) through hydrogen bond cross-linking between the VPh units via BDA. The micelles had the azobenzene moieties at the cores and the UV absorbents at the coronas. The micelles showed a small color difference in color fading experiments, in comparison with the unimers and with micelles having no UV absorbent at the coronas. It is significant that the diblock copolymer forms the micelles and has the UV absorbents at the coronas to suppress the color fading. Furthermore, the chain length of ,-diamines had no effect on the hydrodynamic radius of the micelles, but affected the aggregation number and the cmc.     

Rhenium(V) Complexes of N,N′-Ethylenebis(2-mercaptopropanamide). Synthesis,Characterization, and X-ray Crystal Structures

The preparation of benzoyl-protectcd N,N′-ethylenebis(2-mercaptopropanamide) (H₄emp) and its ligand-exchange reaction with ReO₂(en)₂Cl are described. Three diastereomers, [syn-ReO(meso-emp)]; [anti-ReO(meso-emp)]-, and a pair of cnantiomers, [ReO(rac-emp)]-, were formed due to syn and anti orientation of the two methyl groups of the ligand relative to the ReO core. The diastereomers were separated by reverse phase C₁₈ semipreparative HPLC and isolated as salts of [Ph₄As][ReO-(emp)]. The structures of [Ph₄ As][ReO(meso-emp)] were determined by single-crystal X-ray analyses. [Ph₄As][syn-ReO(mesocmp)]H₂O crystallizes in triclinic space group Pl with a = 10.326(3) Å, b = 13.672(4) A, c = 14.023(5) Å, α = 61.20(2)°, β =74.74(3)°, γ= 75.68(2)° V = 1656.6(8) ų, Z = 2, Dc = 1.676 gmL^?1, F(000) = 824 and R = 0.0329 for 5877 unique reflections. For (he complex [Ph₄As][anti-ReO(meso-emp)], the crystal data are: monoclinic, space group P2₁/n, a = 9.128(2) Å, b = 24.284(7) Å, c = 14.112(4) Å, β = 93.41(2)° V = 3122.5(15) À³, Z = 4, Dc = 1.740 gmL^?1, F(000) = 1608 and R = 0.0361 for 5487 unique reflections. In both structures the rhenium atom is penta-coordinated and in an approximately square pyramidal environment.     

Palladium-Catalysed Amination of Hindered Aryl Halides with 9H-Carbazole

Palladium-catalysed Buchwald–Hartwig amination of ortho-substituted hindered aryl bromides or chlorides with 9H-carbazole has been investigated. In the amination of 1-bromo- or chloronaphthalene with 9H-carbazole, the combined use of Pd₂(dba)₃ as a Pd precursor, Buchwald ligands with two tert-butyl groups and LiOtBu or lithium hexamethyldisilazide as a base led to satisfactory yields. N,N’-Bis[2,6-bis(diphenylmethyl)-4-methoxyphenyl]imidazol-2-ylidene (IPr*^OMe), which is a bulky N-heterocyclic carbene ligand, showed similar activity as Buchwald ligands with two tert-butyl groups. In contrast, only IPr*^OMe provided satisfactory yields in the amination of 2-bromo-1,1′-biphenyl with 9H-carbazole. The amination of 2-bromo- or chlorotoluene and 1-(2-bromo- or chlorophenyl)naphthalene with 9H-carbazole proceeded smoothly when the IPr*^OMe ligand was used.     

Polymers from 1,2-Disubstituted Ethylenic Monomers. V. Radical Polymerization of Dimethyl Maleate in the Presence or Absence of Isomerization Catalyst

Although dimethyl maleate (DMM) did not give any homopolymer with a radical initiator, it was polymerized in the presence of some amines via a monomer-isomerization radical polymerization mechanism, i.e., DMM isomerized to dimethyl fumarate (DMF) which then homopolymerized. For this polymerization, some primary or secondary aliphatic amines served as isomerization catalysts, and morpholine showed the most efficient activity. The activation energies for the monomer-isomerization radical polymerization of DMM with di-tert-butyl peroxide in the presence of morpholine and for the isomerization from DMM to DMF with morpholine were 95.9 and 23.0 kJ/mol, respectively. Morpholine was also observed to act as a retarder in radical polymerization of DMF. Moreover, the relationships between rates or copolymer compositions and the feed monomer compositions in the copolymerization of DMM with styrene in the presence of morpholine were found to become close to those of DMF with styrene, although both relationships were different in the absence of morpholine.     

(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺反相微乳液共聚合特性研究

选用SPAN80与OP10复合乳化剂、K₂S₂O₈-Na₂SO₃氧化还原引发剂,进行(2-甲基丙烯酰氧乙基)三甲基氯化铵-丙烯酰胺反相微乳液共聚合反应.研究了单体配比、电解质浓度和乳化体系的油水比对共聚物分子量及离子度的影响,考察了该共聚合体系的反应特性.     

Vinyl monomers bearing chromophore moieties and their polymers. V. Synthesis and fluorescence behavior of a vinyloxy monomer bearing electron-accepting chromophore moiety,N-(2-(vinyloxy)ethyl)-1,8-naphthalimide,and its polymer

A vinyloxy monomer bearing electron-accepting chromophore, N-(2-(vinyloxy)ethyl)-1,8-naphthalimide (VOENI), was synthesized by reaction of potassium 1,8-naphthalimide with 2-chloroethyl vinyl ether. VOENI can be homopolymerized by cationic initiation and copolymerized with maleic anhydride (MAn) under radical initiation. The fluorescence behaviors of VOENI and its polymers were investigated. It has been found that the fluorescence intensity of the VOENI monomer is much lower than that of its polymers at the same chromophore concentration. This means that a “structural self-quenching effect” (SSQE) has been also observed in the vinyloxy monomer consisting of an electron-accepting chromophore, which has opposite electronic structure in comparison with acrylates bearing electron-donating chromophores as we have reported previously. The SSQE is attributed to the charge-transfer interaction between the electron-accepting chromophore and the electron-donating double bond in the same molecule. The fluorescence quenching of 1,8-naphthalic anhydride and P(VOENI-co-MAn) by ethyl vinyl ether (EVE), dihydrofuran, triethylamine (TEA), etc. evidences that the electron-rich vinyloxy group does act as an important role in the SSQE of VOENI. C₆₀ can also quench the fluorescence of the polymers, and an upward deviation from the linearity of the Stern–Volmer plot was observed showing that C₆₀ acted as a powerful electron donor to quench the fluorescence of the copolymer. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1111–1116, 1998     

OLEFIN SYNTHESIS USING LITHIUM DERIVATIVES OF N,N,N',N'-TETRAMETHYLDIAMIDES OF ARYLMETHANEPHOSPHONIC ACIDS

Abstract

The reaction of lithium derivatives of N,N,N',N'-tetramethyldiamides of arylmethanephosphonic acids (1-Li) with aldehydes 2 is studied. It is found that under certain reaction conditions (THF, 5 hrs at -70°C and then allowing to warm to room temperature) the aldol stage of the reaction is highly stereoselective, only erythro adducts (2-hydroxyphosphonamides) 3, 4 being formed in 47–75% yields. By heating of 3 and 4 in neutral medium the corresponding (Z)-olefins 5, 6 are obtained (yields 64–74%). It is established that an acid catalyzed olefination of 2-hydroxyphosphonamides is also possible, but the reaction is not stereospecific.     

1-(3-硝基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯与阳离子表面活性剂显色反应的研究及应用

在NaOH碱性介质中,1 (3 硝基苯基) 3 [4 (苯基偶氮)苯基] 三氮烯(m NPPAPT)分别与阳离子表面活性剂(CS)溴化十六烷基三甲铵(CTMAB)、溴化十二烷基二甲基苄铵(DDMBAB)、溴化十六烷基吡啶(CPB)和溴化十四烷基吡啶(TPB)反应显色形成离子配合物,它们与m NPPAPT形成离子配合物比均为2∶1。CTMAB、CPB、TPB、DDMBAB与m NPPAPT形成配合物最大吸收波长分别位于538、538、625、637nm,表观摩尔吸光系数达(103～104)L·mol-1·cm-1。研究了测定微量阳离子表面活性剂的条件,建立了新的分析方法,并应用于实样分析。     

Reactive polymers incorporating silyl enol ether groups. I. synthesis by radical polymerization of 2-(trimethylsiloxy)-butadiene and 2-(tert)-butyldimethylsiloxy butadiene

2-(Trimethylsiloxy)butadiene (TMSBD) and 2-(tert-butyldimethylsiloxy)butadiene (TBMSBD) were copolymerized with styrene (St) and methyl methacrylate (MMA) under free-radical conditions. The obtained polymers were found to contain reactive silyl enol ether groups in a ratio identical to the TMSBD or TBMSBD molar fraction in the copolymer. All investigated samples displayed only 1,4- and 3,4-microstructures. The influence of several experimental factors on the yields, rates of polymerization, microstructures, and copolymer compositions were examined. Monomer reactivity ratios r₁ and r₂ at 60°C were determined from copolymer composition curves at low conversions. The homopolymerization of TBMSBD was also investigated and results were compared with those previously obtained for TMSBD. A slight increase in rates was observed and was rationalized on the basis of the higher viscosity resulting from the structural change in the monomer. Thermal stabilities of the synthesized polymers were investigated by TGA and their glass transition temperatures were determined by DSC. All measurements are compatible with a possible use of TMSBD and TBMSBD copolymers as reactive polymers. © 1996 John Wiley & Sons, Inc.     

Acetals and ethers,XVII. One- or two-step syntheses of 2-(2-alkoxyethyl)-1,3-dioxacyclanes

2-(2-Alkoxyethyl)-1,3-dioxanes (1) were prepared by ap-toluenesulfonic acid-catalyzed, one-step reaction of propenal with a mixture of aliphatic alcohol and trimethylene glycol in good yields. The transacetalization reaction of 1,1,3-trialkoxypropanes (3) with ethylene glycol or propylene-(1,2)glycol afforded good yields of pure 2-(2-alkoxyethyl)-1,3-dioxolanes (5 or6), respectively. This reaction proceeds through an intermediate 1,3-dialkoxy-1-(2-hydroxyalkoxy)-propane.

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Ein- oder Zweistufensynthese von 2-(2-Alkoxyethyl)-1,3-dioxacyclanen

Zusammenfassung In der durchp-Toluolsulfonsäure — katalysierten, direkten Reaktion von Propenal mit einem Gemisch von aliphatischem Alkohol und Trimethylenglykol wurden die entsprechenden 2-(2-Alkoxyethyl)-1,3-dioxane (1) in guten Ausbeuten erhalten. Die Umacetalisierung von 1,1,3-Trialkoxypropanen (3) mit Ethylenglykol oder 1,2-Propylenglykol lieferte 2-(2-Alkoxyethyl)-1,3-dioxolane (5 oder6) in guten Ausbeuten. Die Umacetalisierungsreaktion von 1,1,3-Trialkoxypropanen verläuft über 1,3-Dialkoxy-1-(2-hydroxyalkoxy)-propane als Zwischenprodukte.

     

核苷研究Ⅸ3-甲硫基-7-氧代吡唑并(5,4-e)-1,2,4-三嗪核苷合成研究

对3-甲硫基-7-氧代吡唑并(5,4-e)-1,2,4-三嗪的成苷反应进行了研究。当保护基为乙酰基时,生成的核昔β-体为主产物。当保护基为苯甲酰基时全部是β-体。端应构型用~1H NMR确定。在五元环中,顺位质子比反位质子裂分常数大。     

Synthesis,Characterization, Antimicrobial Activities,and Structural Studies of Lanthanide (III) Complexes with 1-(4-Chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1-thiosemicarbazone

Twelve coordinate lanthanide (III) complexes with the general composition [Ln L₃X_n(H₂O)_n] where Ln = Pr(III), Sm(III), Eu (III), Gd (III), Tb (III), Dy (III), X = Cl^?1, NO₃ ^?2, n = 2–7, and L is 1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1- thiosemicarbazone have been prepared. The lanthanide complexes (5) were derived from the reaction between 1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)prop-2-en-1-thiosemicarbazone (4) with an aqueous solution of lanthanide salt. Chalcone thiosemicarbazone ligand (4) was prepared by the reaction of [1-(4-chlorophenyl)-3-(4-fluoro/hydroxyphenyl)]prop-2-enone (chalcone) (3) with thiosemicarbazide in the presence of hot ethanol. All the lanthanide-ligand 1:3 complexes have been isolated in the solid state, are stable in air, and characterized on the basis of their elemental and spectral data.

Thiosemicarbazone ligands behave as bidentate ligands by coordinating through the sulfur of the isocyanide group and nitrogen of the cyanide residue. The probable structure for all the lanthanide complexes is also proposed. The chalcone thiosemicarbazone ligands and their lanthanide complexes have been screened for their antifungal and antibacterial studies. Some of the synthesized lanthanide complexes have shown enhanced activity compared with that of the free ligand.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

2-Phenyl-2-(2-pyridyl)imidazolidine (PPI) as New Catalyst in the Efficient,Mild, and Regioselective Conversion of Epoxides to Thiocyanohydrines with Ammonium Thiocyanate

2-Phenyl-2-(2-pyridyl)imidazolidine (PPI) catalysis the addition of thiocyanate ion to epoxides to afford g -hydroxy thiocyanate in high yields, mild conditions, and regioselectivity. Thus, several 2-hydroxyethyl thiocyanates, which are useful intermediates toward biological active molecules, are obtained easily in very good yields.     

Reaction of 2-(2-Azahetaryl)-4-chloro-3-oxobutyronitriles with Substituted Benzaldehyde Hydrazones. Unexpected Formation of 4-Arylideneamino-2-(1-R-benzimidazol-2-yl)-3-oxobutyronitriles

The reaction of 2-(2-azahetaryl)-3-oxo-4-chlorobutyronitriles with substituted benzaldehyde hydrazones gives 4-arylideneamino-2-(1-R-benzimidazol-2-yl)-3-oxobutyronitriles, the structures of which were proved using spectroscopic data, the results of elemental analysis, and through their chemical reactions. It was found that the reaction course depends on the basicity of the heterocyclic fragment in the starting nitrile. A likely mechanism for the process is proposed.     

Synthesis,characterization, and crosslinking of novel stars comprising eight poly(isobutylene‐azeotropic‐styrene) copolymer arms with allyl or hydroxyl termini. I. Living azeotropic copolymerization of isobutylene and styrene

The overall objective of this research is the creation of novel star polymers consisting of well‐defined stable cores out of which radiate multiple poly(isobutylene‐co‐styrene) [P(IB‐co‐St)] arms whose glass‐transition temperature (T_g) can be controlled over a wide range (?73 to +100 °C) and whose arm termini are fitted with multipurpose (e.g., crosslinkable) functionalities. The first article of this series relates the synthesis and characterization of azeotropic IB/St copolymers [P(IB‐aze‐St)], which are to be subsequently used as end‐functional arms of the target stars. The P(IB‐aze‐St)s are models for statistical IB/St copolymers. The azeotropic composition is 21/79 (mol/mol) IB/St, and NMR, Fourier transform infrared, and gel permeation chromatography techniques demonstrate copolymer compositional homogeneity over the 12–96% conversion range. Conditions were developed for living azeotropic IB/St copolymerization. The livingness of the azeotropic copolymerization was proven by kinetic investigations. P(IB‐aze‐St)s with number‐average molecular weights of up to 24,000 g/mol and polydispersity indices (weight‐average molecular weight/number‐average molecular weight) less than 1.5 were prepared. The copolymerization reactivity ratios were determined: r_IB = 3.41 ± 0.23 and r_St = 1.40 ± 0.26. The effect of the P(IB‐aze‐St) molecular weight on T_g was studied by DSC. T_g increases linearly with the number‐average molecular weight and reaches a plateau at 62 °C at 24,000 g/mol. The heat stability of P(IB‐aze‐St) was investigated by thermogravimetric analysis, and a 5% weight loss was found at 250 °C in air. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1515–1524, 2001     

Synthesis, Characterization, Spectroscopic Properties of 2-（4-Dimethylaminophenyl）-5-fluoro-6-（morpholin-4-yl）-1H-benzimidazole and its Interaction with Calf Thymus DNA

Benzimidazole compounds have attracted a renewed interest recently owing to theirpotential applications in high-performance composite materials, electronic chemicals,photosensitive materials, and their special potentials in biological and/or medicinalapplication1,2. Typically, aromatic compounds with near planar structures and contain-ing hydrogen-donor groups or groups, which are capable of being protonated, havespecial interactions with DNA via intercalation, hydrogen-bonding, and so on3.Me…     

Synthesis and characterization of cerium,thorium, and uranyl complexes with ( E )-4-(4-methoxyphenoxy)-4- oxobut-2-enoic acid

(E)-4-(4-Methoxyphenoxy)-4-oxobut-2-enoic acid and its Ce(IV), Th(IV), and UO₂(II) complexes were synthesized and characterized by MS, elemental analysis, IR, UV, TG-DTA, and NMR. The complexes have composition [CeL₂(OH)₂ · 2H₂O] · H₂O, [ThL₂(OH)₂ · 2H₂O] · H₂O, and [UO₂L₂ · 2H₂O] · H₂O. Molar conductance data confirm that the three complexes are nonelectrolytes. The IR and NMR results show that the carboxylates coordinate to the metal ions bidentate, and the ester carboxylic groups do not take part in coordination. Luminescence spectra of the ligand and complexes in DMSO at room temperature were also studied showing strong luminescence of the metal ions.