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1.
Laine研究小组直接用二氧化硅和乙二醇在无机碱的作用下,合成了五配位硅化合物:Laine研究的意义在于他开创了低温合成配位有机硅化合物的先河,这种方法有四个优点,(1)能耗小;(2)原料来源丰富,价格低廉,二氧化硅占地壳的1/4,乙二醇也很便宜;(3)污染小;(4)制得的五配位硅化合物反应活性非常高。但Laine在聚合物方面做的工作较少,过去只是把这个方法应用于高性能陶瓷玻璃的制备以及离子导电聚合物的研究中J,主要是解决不了五配位硅钾化合物的水解可逆性问题。  相似文献   

2.
配位有机硅在聚醚氨酯中的应用   总被引:3,自引:0,他引:3  
研究了直接从无定型二氧化硅出发,与乙二醇、氢氧化钾反应,生成高反应活性的五配位硅钾络合物,并以此为原料与2-氯乙醇反应制备双羟基四配位有机硅单体,该单体作为扩连剂再与异氰酸酯基封端的聚醚或聚酯进行低温溶液缩聚反应合成含硅聚醚氨酯,经红外光谱,热重分析,胶渗透色法测定分子量等对合成的物质作了结构表征,热重分析表明该聚合物的耐热性能有所提高,胶渗透色谱法测定分子量高于10万。  相似文献   

3.
研究了直接由SiO2 (沉淀白炭黑 )、乙二醇、KOH为原料低温合成高活性的五配位有机硅络合物 [KSi (OCH2 CH2 O) 2 OCH2 CH2 OH],然后与环氧氯丙烷反应 ,生成含硅环氧化合物 ,并借助于红外、核磁共振、热分析、能谱元素分析等现代测试手段 ,对合成的产物进行了结构表征  相似文献   

4.
直接由SiO2低温合成含硅环氧化合物及其结构表征   总被引:9,自引:0,他引:9  
研究了直接由SiO2(沉淀白炭黑)、乙二醇、KOH为原料低温合成高活性的五配位有机硅络合物[KSi-(OCH2CH2O)2OCH2CH2OH]然后与环氧氯丙烷反应,生成含硅环氧化合物,并借助于红外、核磁共振、热分析、能谱元素分析等现代测试手段,对合成的产物进行了结构表征。  相似文献   

5.
双羟基四配位硅单体的合成   总被引:10,自引:0,他引:10  
以无定型二氧化硅为起始原料,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2-氯乙醇反应制备了双羟基四配位硅化合物 。探讨了不同反应条件(如温度、不同反应物摩尔比、催化剂等)对该反应的影响 ,并对合成的化合物做了红外光谱、核磁共振(^1H,^13C)、元素分析、能谱元素 分析等结构表征。  相似文献   

6.
苯并咪唑衍生物具有一定的抗病毒能力[1],一些苯并咪唑衍生物已用作农用抗植物病毒剂[2].一锅煮合成反应时间较长,产率中等[3,4].本文用取代邻苯二胺和水杨酸为原料,吡啶为溶剂,POCl3为催化剂,微波辐射法合成了标题化合物.  相似文献   

7.
合成了铜锶异金属配位聚合物,并通过元素分析和IR光谱对其进行了表征,利用X射线单晶衍射测定了其晶体结构.该化合物为具有{[(CuL)2Sr(H2O).Sr2(H2O)7].2H2O.0.5CH3OH}n化学组成的二维层状配位聚合物[H4L=N-(3-羧基水杨醛)-N′-(2-羟基苯甲酰基)乙撑二胺],其结构单元由两个相邻的片段组成,这些结构单元彼此相互配位,从而形成了一种结构新颖的层状配位聚合物.  相似文献   

8.
近年来,配位聚合物由于在光学、电学、磁学、催化、分离及吸附等方面具有潜在的功能性,处于化学、材料、生物、物理等许多学科的交叉点,成为当前最活跃的前沿研究领域之一[1~8],因此进一步合成具有特定结构和功能的配位聚合物具有非常重要的意义和价值[9~12].  相似文献   

9.
直接由SiO2合成双羟基四配位硅化物及其结构表征   总被引:2,自引:0,他引:2  
化合物;直接由SiO2合成双羟基四配位硅化物及其结构表征  相似文献   

10.
镍是生物中必要的痕量元素,能促进体内铁的吸收、红细胞的增长、氨基酶的合成,镍可能是DNA和RNA的一种结构稳定剂[2].大多数席夫碱化合物具有抗肿瘤、抗菌等生物活性,而腙类化合物因具有优良的生物活性、强配位能力和多样的配位形式,在农药、医药及分析等方面的应用受到广泛的关注[3~9].我们实验室长期以来从事席夫碱及其金属配合物的合成和生物活性研究,我们曾报道过水杨酰腙Schiff碱配体与Cu(Ⅱ)配合的结构和生物活性[10],为了进一步研究镍配合物的配位构型及其性能,本文报道了标题化合物镍的四配位结构.  相似文献   

11.
The zwitterionic lambda(5)Si,lambda(5)Si'-disilicates 1-8 were synthesized and characterized by solid-state and solution NMR spectroscopy. In addition, compounds 26 H(2)O, 32 CH(3)CN, 45/2 CH(3)CN, 6CH(3)OH, 7, and 8CH(3)OHCH(3)CN were studied by single-crystal X-ray diffraction. The optically active (Delta,Delta,R,R,R,R)-configured compounds 1-8 contain two pentacoordinate (formally negatively charged) silicon atoms and two tetracoordinate (formally positively charged) nitrogen atoms. One (ammonio)alkyl group is bound to each of the two silicon centers, and two tetradentate (R,R)-tartrato(4-) ligands bridge the silicon atoms. Although these lambda(5)Si,lambda(5)Si'-disilicates contain SiO(4)C skeletons, some of them display a remarkable stability in aqueous solution as shown by NMR spectroscopy and ESI mass spectrometry.  相似文献   

12.
The solvothermal reaction of (HOCH2CH2)3N with [(n-C4H9)4N]3[H3V10O28] and MnCl2 x 4H2O in CH3CN and CH3OH yields a novel cationic heteropolyoxovanadium(IV) cluster, [Mn(II)V(IV)6O6[(OCH2CH2)2N(CH2CH2OH)]6]2+, containing a fully reduced new cyclic [MnV6N6O18] core with the Anderson structure.  相似文献   

13.
Product formation pathways in the photolytically initiated oxidation of CH3OCH3 have been investigated as a function of temperature (298-600 K) and pressure (20-90 Torr) through the detection of HO2 and OH using Near-infrared frequency modulation spectroscopy, as well as the detection of CH3OCH2O2 using UV absorption spectroscopy. The reaction was initiated by pulsed photolysis with a mixture of Cl2, O2, and CH3OCH3. The HO2 and OH yield is obtained by comparison with an established reference mixture, including CH3OH. The CH3OCH2O2 yield is also obtained through the procedure of estimating the CH3OCH2O2/HO2 ratio from their UV absorption. A notable finding is that the OH yield is 1 order of magnitude larger than those known in C2 and C3 alkanes, increasing from 10% to 40% with increasing temperature. The HO2 yield increases gradually until 500 K and sharply up to 40% over 500 K. The CH3OCH2O2 profile has a prompt rise, followed by a gradual decay whose time constant is consistent with slow HO2 formation. To predict species profiles and yields, simple chlorine-initiated oxidation model of DME under low-pressure condition was constructed based on the existing model and the new reaction pathways, which were derived from this study. To model rapid OH formation, OH direct formation from CH3OCH2 + O2 was required. We have also proposed that a new HCO formation pathway via QOOH isomerization to HOQO species and OH + CH3OCH2O2 --> HO2 + CH3OCH2O are to be considered, to account for the fast and slow HO2 formations, as well as the total yield. The constructed model including these new pathways has successfully predicted experimental results throughout the entire temperature and pressure ranges investigated. It was revealed that the HO2 formation mechanism changes at 500 K, i.e., HCO + O2 via HCHO + OH and the above proposed direct HCO formation dominates over 500 K, while a series of reactions following CH3OCH2O2 self-reaction and OH + CH3OCH2O2 reaction mainly contribute below 500 K. The pressure dependent rate constant of the CH3OCH2 thermal decomposition reaction has been separately measured since it has large negative sensitivity for HO2 formation and is essential to eliminate the ambiguity in the CH3OCH2 + O2 mechanism at higher temperature.  相似文献   

14.
采用表面改性和离子交换相结合的方法制备了Ni2(OCH3)2/SiO2负载型双核金属甲氧基配合物催化剂,利用红外光谱(IR)、程序升温脱附(TPD)、程序升温表面反应(TPSR)和微反技术考察了催化剂的表面结构以及CO2和CH3OH的化学吸附和反应性能.结果表明:Ni2(OCH3)2/SiO2中Ni2+与载体SiO2表面O2-以双齿配位形式键合,甲氧基以桥基形式联结双金属离子形成双核物种Ni2(OCH3)2;CO2在催化剂表面存在甲氧碳酸酯基物种和桥式两种吸附态,CH3OH则只有一种分子吸附态;在100~200℃条件下,CO2和CH3OH在催化剂上的反应产物主要是DMC和H2O;根据反应结果,讨论了催化反应机理.  相似文献   

15.
Phosphonium ions CH(3)P(O)OCH(3)(+) (93 Th) and CH(3)OP(O)OCH(3)(+) (109 Th) react with 1,4-dioxane to form unique cyclic ketalization products, 1,3,2-dioxaphospholanium ions. By contrast, a variety of other types of ions having multiple bonds, including the acylium ions CH(3)CO(+) (43 Th), CH(3)OCO(+) (59 Th), (CH(3))(2)NCO(+) (72 Th), and PhCO(+) (105 Th), the iminium ion H(2)C[double bond]NHC(2)H(5)(+) (58 Th) and the carbosulfonium ion H(2)C[double bond]SC(2)H(5)(+) (75 Th) do not react with 1,4-dioxane under the same conditions. The characteristic ketalization reaction can also be observed when CH(3)P(OH)(OCH(3))(2)(+), viz. protonated dimethyl methylphosphonate (DMMP), collides with 1,4-dioxane, as a result of fragmentation to yield the reactive phosphonium ion CH(3)P(O)OCH(3)(+) (93 Th). This novel ion/molecule reaction is highly selective to phosphonium ions and can be applied to identify DMMP selectively in the presence of ketone, ester, and amide compounds using a neutral gain MS/MS scan. This method of DMMP analysis can be applied to aqueous solutions using electrospray ionization; it shows a detection limit in the low ppb range and a linear response over the range 10 to 500 ppb.  相似文献   

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