MANGANESE (IV)-INITIATED GRAFTING OF TRIMETHYLALLYLAMMONIUM CHLORIDE ONTO CARBOXYMETHYLCELLULOSE

Graft copolymerization of cationic monomer trimethylallylammonium chloride onto anionic carboxymethylcellulose has been investigated in aqueous medium using potassium permanganate/sulphuric acid redox system as initiator, involving the identification of grafting, the mechanism for grafting and various factors affecting grafting. The prepared cellulosic copolymers with amphoteric functional groups have been found to be effective to retard the hydration of clay minerals, showing a potential use as new clay-hydration suppressant for oilfields.     

BENZOPHENONE PHOTOSENSITIZATION OF 2'-DEOXYGUANOSINE: CHARACTERIZATION OF THE 2R AND 2s DIASTEREOISOMERS OF 1-(2-DEOXY-β-D-erythoW-PENTOFURANOSYL)-2-METHOXY-4,5-IMIDAZOLIDINEDIONE. A MODEL SYSTEM FOR THE INVESTIGATION OF PHOTOSENSITIZED FORMATION OF DNA-PROTEIN CROSSLINKS

Abstract Benzophenone-mediated photosensitization of 2'-deoxyguanosine and its 3',5'-di-O-acetyl derivative, used as DNA model compounds, in oxygen-saturated water-methanol (1:1) solution results in the nucleophilic addition of methanol to the guanine base. The resulting modified nucleosides have been isolated by reverse-phase high-performance liquid chromatography and characterized by extensive spectroscopic measurements including ¹³C and ^IH nuclear magnetic resonance, fast atom bombardment mass spectrometry and circular dichroism as the 2R and 2s diastereoisomers of 1-(2-deoxy-˜-o-erythro-pentofuranosyl)-2-methoxy-4,5-imidazolinedione and their related 3',5'-di-O-acetyl derivates. Information concerning the absolute configuration of the two pairs of diastereoisomers was inferred from detailed nuclear Overhauser effect experiments. A reaction mechanism, involving guanine radical intermediates, is proposed to explain the generation of these new guanine photoproducts.     

5—（L—盖氧基）—2（5—H）—呋喃酮与硝酮体系环加成反应的理论研究

选取模型化合物,用AMl MO方法从理论上研究了手性的5-(L-盖氧基)-2(5—H)-呋喃酮与偶极硝酮体系环加成反应的机理。优化了反应过程各驻点的几何构型,计算了反应的活化焓、活化熵和反应速率常数,结果表明,该反应为同面的协同过程,非对映专一性产物的形成估计是由于盖氧基及硝酮分子上苯取代基的空间效应所致。     

显色剂1-羟基-2-(5-NO2-2-吡啶偶氮)-8-氨基-3,6-萘二磺酸与镍显色反应的研究

探讨了显色剂 1 羟基 2 (5 NO2 2 吡啶偶氮 ) 8 氨基 3,6 萘二磺酸 (简称 5 NO2 PAH )与镍离子显色的适宜条件及其共存离子的影响 ,建立了 5 NO2 PAH测定镍的新显色体系。结果表明 ,在 pH 8.5～ 10 .0范围内 ,镍与试剂形成稳定的 1∶2配合物 ,其最大吸收峰位于 6 5 3nm ,表观摩尔吸光系数εNi=1.0 7× 10 5L·mol- 1·cm- 1,镍的浓度在 0～ 5 μg/ 10ml范围内遵守比耳定律。方法用于合金中镍的测定 ,结果满意。     

新试剂1-(2,3,5-三氮唑偶氮)-2-萘酚与锌的显色反应研究及应用

研究了１－（２,３,５－三氮唑偶氮）－２－萘酚（ＴＺＡＮ）锌显色反应,结果表明,在ＰＨ６．０－８．５的乙醇水溶液中ＴＺＡＮ与锌形成稳定的红色络合物,其最大吸收波长为５２５ｎｍ,表观摩尔吸光系数为３．５６＊１０＾４Ｌ．同,络合物的组成为Ｚｎ：ＴＺＡＮ＝ｌ：２,锌浓度在０－１．２μｇ．ｍｌ＾－１范围内遵守比耳定律,方法用于人发中微量锌的直接测定,结果满意。     

THE REACTION OF BENZOYL SUBSTITUTED HETEROCYCLIC KETENE AMINALS WITH ARYL AZIDES.A FACILE APPROACH TO SYNTHSIZE 1, 5-DIARYL-4-(2-IMIDAZOLINYL)-1, 2, 3-TRIAZOLES

Heterocyclic ketene aminals 1 react with aryl azides 2 to give thetitled compounds 3, and in some cases also with the formation offused heterocycles 4.     

CONVERSION OF EPOXIDES INTO 2-HYDROXYETHYL THIOCYANATES WITH NH4SCN IN THE PRESENSE OF 2,6-BIS[2-(O -AMINO PHENOXY)METHYL]-4-BROMO-1-METHOXYBENZENE (BABMB) AS CATALYST

A convenient and efficient procedure for the ring-opening of 1,2-epoxyethanes with ammonium thiocyanate in the presence of 2,6-bis[2-(o -aminophenoxy)methyl]-4-bromo-1-methoxybenzene (BABMB) is described. In this study, a reagent and conditions have been discovered with which the individual 2-hydroxyethyl thiocyanates can be synthesized in high yield and with more than 90% regioselectivity. Thus, several 2-hydroxyethyl thiocyanates, useful intermediates toward biological-active molecules, are easily obtained in very good yields.     

PAN-S浸渍树脂富集方波溶出法测定痕量的铅、镉、铜和锌

用1-(2-吡啶偶氮)-2-萘酚-6-磺酸(PAN-S)水溶液处理201×7强碱性阴离子交换树脂,制备了具有PAN-S功能团的浸渍树脂。经过最佳条件选择,在同一水样中,可以同时富集Pb2 、Cu2 、Zn2 、Cd2 。实验结果表明,PAN-S树脂用于痕量元素的分离富集具有交换速度快、易于洗脱、富集倍数大、选择性好等优点。建立了PAN-S树脂富集-分离铅、镉、铜和锌离子的方波溶出法的测定方法,并可用于海水中的测定,结果令人满意。     

聚芳醚酮高温长时间下的断裂行为──2．物理老化的影响

研究了聚芳醚酮在２００℃下长时间放置过程中的密度，热焓，屈服及应力松弛行为随时间的变化规律．结果表明，随放置时间的增长，材料的结构形态与物性随时间的变化速率在１０小时后急剧减慢．文中对物性变化的时间依赖性进行了讨论．在应力松弛过程中出现银纹的现象可归结为物理老化过程中分子链间排列逐渐紧密的结果．     

ELECTRON IMPACT INDUCED ELIMINATIONS. III. ELIMINATION OF SO2 vs. REMOTE GROUP INTERACTIONS IN ARYL ALLYL SULFONES, 1,4-BIS(ARYLSULFONYL)-2-BUTENES, 1-ARYLOXY-4-ARYLSULFONYL-2-BUTENES,AND 4-[(PHENYLSULFONYL)METHYL]-2H-1-BENZOPYRANS

Abstract

Aryl allyl sulfones, analogous to propynyl sulfones, undergo facile SO₂ elimination under electron impact. However, the 2-butenyl-1,4-diaryl sulfones, analogous to the 2-butynyl-1,4-diaryl sulfones exhibit propensities of remote group interaction and extrusion of the C₄H₆ moiety separating the sulfone functions. Where such remote group interaction is structurally prevented, as in the 4-[(phenylsulfonyl)methyl]-2H-1-benzopyrans, SO₂ extrusion is a major fragmentation pathway.     

聚全氟三嗪的合成研究Ⅱ.2-三氟甲基-4,6-二(4′-碘-2′-氧杂六氟丁基)-1,3,5-三嗪的聚合研究

本文研究三嗪单体Ⅰ的纯化和聚合,粗品单体含有化合物Ⅱ,Ⅲ和Ⅳ等杂质,可用低温结晶并经氧化铝短柱过滤的方法除去。Ⅰ在金属汞存在下,经紫外线照射,在溶剂中或无溶剂情况下聚合。所得聚合物Ⅴ具有较好的耐热性能,其主链上几乎不存在未成环的薄弱链节,Ⅴ的平均分子量为1.33—2.0×10~4(聚合度为27—42),在氮气中失重10％。时的温度为340℃。     

PERI-INTERACTIONS IN NAPHTHALENES, 21. SUBSTITUENT EFFECTS IN (8-DIMETHYLAMINO-NAPHTH-1-YL)- AND [2-DIMETHYLAMINO-METHYL)PHENYL] - PHOSPHINES ON THE 31P-NMR SIGNAL POSITIONS

Abstract

Contrary to claims in the literature, the ³¹P NMR signal positions of ortho-dimethylaminomethyl-substituted triarylphosphines do not provide evidence for hypercoordination at phosphorus; the observed highfield shifts relative to triphenylphosphine are rather due to the ortho-effect. In (8-dimethylamino-naphth-1-yl)phosphines, the signal positions similar to that of triphenylphosphine are the result of the highfield ortho-effect and a lowfield peri-substituent effect of about the same magnitude whose nature remains to be explored.     

SYNTHESIS,PROPERTIES AND AN ELECTROACTIVE FILM OF RUTHENIUM(II) COMPLEXES WITH THE PYRIDINE DERIVATIVE LIGAND: trans-[RuCl2(pmp)4].(pmp=3-(PYRROL-1-YLMETHYL)PYRIDINE)

Abstract

In this work we report the synthesis, characterization and electrochemistry of the complex trans-[RuCl₂(pmp)₄], where pmp=3-(pyrrol-l-ylmethyl)pyridine. The complex was characterize by electronic spectroscopy (Λ_max = 404 nm and ε = 27000), vibrational FT-IR spectroscopy, ¹H and ¹³C NMR, showing results typically in agreement with trans geometry. Cyclic voltammetry reveals a redox process centered on the Ru(II) center (E^1/2 = 0.53V vs. NHE), which is electrochemically and chemically reversible. Spectroelectrochemistry shows the progressive disappearance of bands at 404 and 475 nm and the appearance of a new band at 302 nm during the oxidation process. Cyclic voltammetric experiments were performed to characterize the redox properties of the ruthenium complex; its electropolymerization produced a strongly adhesive conducting polymeric film on platinum and palladium electrodes.     

Me_4Bzo_2[14]六烯(2-)N_4金属配合物的结构和反应性研究 Ⅰ.溴碘加成物的合成和振动光谱研究

本文合成了Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Cu(Ⅱ)大环配合物及其溴碘加成物,研究了远红外和Raman光谱,对MN_4局部进行了伸缩振动的简正坐标分析,求得了各化合物的键角和伸缩力常。通过Raman光谱初步确定了溴碘的存在形式。对溴碘加成物的叠层结构和各化合物的成键进行了讨论。