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制德了由金属离子中和磺化丁基橡胶(M-SⅡR)与苯乙烯-4-乙烯基吡啶共聚物(PSVP0组成的共混物,用FTIR考察该共混物组分间的相互作用。发现当使用含锌离子或铜(Ⅱ)离子的离聚体时,吡啶环的伸缩震动吸收峰从1600cm^-1移动1618cm^-1,表明形成了金属离子与吡啶环的络合物。对于Zn-SⅡR/PSVP共混物,与Zn-N络合物浓度相关的1618cm^-1吸收峰强度随共混的组成的改变而改变,当Zn-SⅡR与PSVP的摩尔比为1:1时达到最大,此时相当于Zn与Nr的比值为1:2。在该共混的中,锌的配位数为2。 相似文献
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接枝共聚的接枝参数表述方法的探讨 总被引:2,自引:0,他引:2
介绍了接枝共聚物接枝参数,如单体转化率、接枝率、接枝效率、均聚物含量及接枝频率,概述了对这些参数在进行表述淀粉接枝共聚时出现的种各种表达形式。在此基础上,指出了这些其在表达上出现的混乱现象。 相似文献
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以α-取代苯并噻吩乙炔及乙烯基为配体,与不同辅助配体键合的金属钌为氧化还原活性端基,分别合成并表征了α-取代苯并噻吩钌乙炔及钌乙烯配合物1和2,两个配合物均经X射线单晶衍射的确证。电化学性质表明配合物1具有较好的氧化还原可逆性,金属氧化态相对于2比较稳定。红外光谱电化学研究表明配合物1和2分别形成1~+和2~+后,与金属相连的ν(C≡C)和ν(C≡O)伸缩振动吸收均发生变化,其中ν(C≡C)变化较大,可能由于形成了Ru=C=C结构;紫外可见近红外光谱电化学研究发现电解后,中性分子1和2在紫外区域的强吸收峰均逐渐降低,1~+分别在可见及近红外580 nm,698 nm及874 nm处出现较弱的3个吸收峰,3个吸收峰可能归属于LMCT吸收。2~+在296 nm处出现1个很弱的吸收峰,这不同于配合物1~+,可能源于2~+的稳定性。 相似文献
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以SiO_2为起始反应物,与乙二醇、氢氧化钾反应,生成高反应活性的五配位硅钾化合物,并以此为原料与等摩尔比的对苄氯苯乙烯反应制备出含双键单官能团的四配位硅单体;然后与丙烯酸甲酯在甲苯溶剂中进行溶液自由基聚合反应,得到支链含硅共聚物。对合成的四配位硅单体及其共聚物采用红外光谱、元素分析、能谱元素分析、热失重分析、差示扫描量热谱分析、凝胶渗透色谱等测试技术进行了结构表征与性能分析。结果表明.四配位硅单体在1 630 cm~(-1)附近的C=C伸缩振动吸收峰在共聚物中消失了,说明共聚反应完全;共聚物的热性能较好.在357℃开始失重;共聚物的玻璃化转变温度为23.4℃,刚好界于聚丙烯酸甲酯的T_g(8℃)和苯乙烯基四配位硅的均聚物的T_8(32.8℃)之间;共聚物的数均分子量为2.2×10~4,多分散系数为1.76。通过测定共聚物在潮湿空气中(相对湿度RH=90%)放置一年后的IR谱和分子量,结果表明与新合成物的数据基本一致,说明Si—O—C键接到支链上的共聚物结构很稳定。 相似文献
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合成以2-(4-溴苯基)苯并咪唑为环金属配体、乙酰丙酮为辅助配体的铱配合物客体单元,并通过Suzuki缩聚方法将客体引入聚芴(PFO)主体中,合成了主链型共聚物。通过元素分析、红外光谱、1 H-NMR等分析手段对产物进行了结构表征,通过紫外吸收光谱、稳态和瞬态荧光光谱对铱配合物、共聚物的光物理性能进行了研究。结果表明:铱配合物最大发射峰位于505nm和535nm,为绿光发射;共聚物同时呈现蓝光主体PFO和绿光客体铱配合物的发射,且随铱配合物含量提高,绿光强度明显增强,显示了主客体能量的部分转移,通过调节共聚物中铱配合物单元的含量,使共聚物的发光颜色从蓝光向绿光转移;当铱配合物的物质的量分数为2%时,蓝色荧光强度大于绿色磷光,共聚物色坐标刚好处于蓝绿交界处,当铱配合物物质的量分数大于2%时,共聚物呈现绿色发光;与铱配合物的荧光量子效率(2.7%)相比,共聚物的荧光量子效率均有显著增加;共聚物热稳定性良好。 相似文献
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在253K和16MPa的压力下,于实验室内合成了氮气水合物,用显微共焦拉曼光谱对其N-N和O-H键伸缩振动的光谱特征进行了研究.结果表明,氮气水合物中的N-N和O—H键的拉曼峰分别为2322.4和3092.1cm^-1,与天然的空气水合物中的数据十分接近.另外,还测定了液氮和溶解于水中的氮分子中N—N键的拉曼峰值,分别为2326.6和2325.0cm^-1.氮气笼型水合物分解的拉曼谱图表明,氮分子同时进入水合物的大笼和小笼中,但由于氮分子在大、小笼中的环境氛围十分接近,其拉曼位移相差不大,故拉曼谱图只能显示N—N键伸缩振动一个峰. 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
The review contains a concise historical account and information on the most significant researches undertaken by the staff
at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry
of Heterocyclic Compounds.
Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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《Tetrahedron》2014,70(21):3377-3384
The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative. 相似文献
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Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields. 相似文献