三（全氟苯基）对羟基苯基硼酸三乙铵的合成与单晶结构

采用三(五氟苯基)硼烷与4-[叔丁基二(甲基)硅氧基]苯基溴化镁格氏试剂反应,再经三乙胺三氢氟酸-四氢呋喃溶液反应脱除保护基,得到(对羟基苯基)三(五氟苯基)硼酸三乙铵(a),在n(4-TBDMSO-C6H4MgBr)/n〔(C6F5)3B〕、n(NEt3.HCl)/n〔(C6F5)3B〕、n(NEt3.3HF)/n〔(C6F5)3B〕分别为3∶1、5.7∶1、1.3∶1的工艺条件下,所得产品质量分数达99.2%,基于三(五氟苯基)硼烷的收率达54.2%,并首次得到该化合物的单晶,X射线单晶结构分析表明,该化合物属正交晶系,Pbca空间群。     

2,2-双(3-氨基苯基)六氟丙烷聚酰亚胺单体的合成及表征

以2,2-双(3-硝基苯基)六氟丙烷为原料,在三氯化铁/炭(FeCl3/C)、水合肼的作用下,还原得到了2,2-双(3-氨基苯基)六氟丙烷聚酰亚胺单体,并对其进行了分析表征。然后,2,2-双(3-氨基苯基)六氟丙烷与4,4’-2-六氟亚异丙基-2-邻苯二甲酸酐(6FDA)在N,N-二甲基甲酰胺(DMF)中缩聚制得聚酰亚胺聚合物。     

新型高活性聚醚多元醇的制备及应用

详细介绍了用三(五氟苯基)硼烷为代表的新型Lewis酸催化剂制备高活性聚醚多元醇的工艺,并介绍了该高活性聚醚多元醇在聚氨酯(PU)泡沫及弹性体中的应用情况,指出用该新型聚醚多元醇制备的PU树脂具有优异的固化特性、力学性能、耐水性和湿热稳定性。     

橙红色荧光粉K2Bi1–xZr(PO4)3:xSm3+的电子结构与荧光性能(英文)

采用常规固相反应合成了无水钾镁矾基荧光粉材料钐(+3)激活磷酸锆铋钾,并用X射线衍射、紫外–可见漫反射光谱、密度泛函理论计算(DFT)和光致发光谱等方法进行了研究。DFT计算表明,磷酸锆铋钾是一种具有间接带隙的绝缘体,带宽为4.26 eV,适合作为荧光主体材料。该荧光粉可被340～425 nm范围内近紫外光有效地激发,发射出一系列钐(+3)的特征发射峰。主要包括562、600、647 nm附近3个发射带,分别对应于钐(+3)离子4G5/2→6HJ (J=5/2, 7/2, 9/2)的能级跃迁。通过改变x值制备了不同钐(+3)浓度的样品,并比较了其发射强度,得出钐(+3)的最佳掺杂浓度为10%(摩尔分数)。因此,钐(+3)激活磷酸锆铋钾材料可作为橙红色荧光粉在照明和显示领域具有一定的应用价值。     

二甲基苯基硅氧基封端聚(二甲基-甲基苯基)硅氧烷共聚物的热分解性能及动力学研究

以1,1,3,3-四甲基二苯基二硅氧烷为封端剂,八甲基环四硅氧烷与甲基苯基环硅氧烷混合物为共聚单体,在阴离子催化剂作用下合成了二甲基苯基硅氧基封端的聚(二甲基-甲基苯基)硅氧烷共聚物。采用非等温TG技术,在惰性气氛和5.0、10.0、15.0和40.0 K min 1线性升温速率条件下,考察了共聚物非等温热降解机理及反应动力学,采用Friedman-Reich-Levi、Flynn-Wall-Ozawa和Kissinger等方法对非等温动力学数据进行分析,所得平均表观活化能分别为113.64、115.69和145.80 kJ mol 1。采用等转化率法确定出共聚物热分解反应符合Avrami-Erofeev方程,反应机理为随机成核和随后生长。采用Crane和Doyle方法研究了不同升温速率对反应级数、活化能和指前因子的影响,结果表明降解反应为一级反应,反应活化能介于152.46~183.13 kJ mol 1之间,指前因子介于4.25×109~4.02×109s 1。同时采用等温TG技术得到失重5%和10%条件下的寿命方程,对共聚物的寿命进行了预测。     

3，5-双（三氟甲基）苯基硅油的合成及性能研究

以3,5-双(三氟甲基)溴苯和甲基三甲氧基硅烷为原料,通过格氏反应和取代反应制备了一种含氟有机硅单体3,5-双(三氟甲基)苯基甲基二甲氧基硅烷;然后将其与二甲基二甲氧基硅烷共水解、平衡聚合制得3,5-双(三氟甲基)苯基硅油.通过FT-IR、1H NMR、19F NMR和元素分析等对含氟有机硅单体和氟硅油进行了表征.含氟硅油的表面张力为20.5 mN/m,大于二甲基硅油(19.0 mN/m).以硅油质量损失10%时的热分解温度来表征材料的热稳定性,二甲基硅油为232.3 ℃,含氟苯基硅油为265.2 ℃,表明含氟苯基硅油的热稳定性比二甲基硅油优越.     

基于Calypso方法分析(GaSb)_n(n=3-6)团簇的电子结构和性质

本论文采用CALYPSO方法,基于全局搜索方法,结合密度泛函理论对(GaSb)n(n=3-6)团簇的结构进行预测和分析。我们对团簇的几何结构特征及键长变化等进行分析,并结合电子结构特征和电荷布居的分析,发现随着团簇的增加,Ga-Sb平均键长逐渐变短,也说明了随着原子数增加,原子之间的作用更强,团簇更稳定。该研究有助于增强人们对GaSb团簇性质的理解和应用。     

Pd(OAc)_2/P(t-Bu)_3催化合成空穴传输材料APB的研究

以二苯基联苯二胺(DPB)和9-溴蒽为原料,在叔丁醇钠强碱环境下,以Pd(OAc)2/P(t-Bu)3为催化剂合成了新型空穴传输材料N,N’-二苯基-N,N’-二蒽基-1,1’-联苯-4,4’-二胺(APB)。得到优化的催化反应条件为:以二甲苯为溶剂在130~138℃回流反应3 h,Pd(OAc)2∶P(t-Bu)3=1∶1.2(摩尔比),P(t-Bu)3/9-溴蒽=0.24%;经元素分析、GC-MS、1H NMR等表征了结构;差示扫描量热仪(DSC)分析结果显示其熔点为324℃,具有良好的热稳定性。     

2-(2,6-二氟苯基)-1H-咪唑-5(4H)-酮的合成及机理的研究

通过N-乙酰氨基-2,6-二氟苯甲酰胺在POCl3催化下脱水制得标题化合物。标题化合物经IR、1HNMR和GC-MS方法进行了结构表征,同时提出了一种可能的反应机理。     

聚(四甲基对硅亚苯基-二甲基)硅氧烷共聚物的制备及其热性质

以对二溴苯为起始原料,在超声辐照下制备得到对二溴苯双格氏试剂,然后与二甲基氢氯硅烷制备得到1,4-双(二甲基硅基)苯)(BDSB)。以B(C6F5)3为催化剂,BDSB与二甲基二甲氧基硅烷缩聚制备得到聚(四甲基对硅亚苯基-二甲基)硅氧烷共聚物(PTMPS-DMS),并对催化剂浓度、反应温度对反应速率的影响进行了研究。29SiNMR表明产物不是严格交替共聚物,具有38%～49%的嵌段结构。PTMPS-DMS的Tg=-56.2℃,起始降解温度氮气、空气中分别为334℃、345℃。在氮气中PTMPS-DMS出现一步热失重,最大热失重温度是529℃,在空气中则分别在539℃、559℃、662℃出现多步热失重。     

BrONO_2与Br(~2P_(3/2))气相反应的密度泛函理论研究

采用密度泛函理论计算方法B3LYP和基组6 31G(d),对BrONO2+Br(2P3/2)的反应机理进行了理论计算,得到各种可能反应途径的过渡态,并经过频率振动分析和内禀反应坐标(IRC)分析加以确认。结果表明:该反应是3通道反应,其中BrONO2+Br→Br2+NO3的反应活化能(5.25kJ/mol)最低,是反应主通道。     

Kinetic and property parameters of poly(ethylene naphthalate) synthesized by solid-state polycondensation

A low molecular weight prepolymer with reactive end groups was annealed at temperatures between 200 and 245°C to obtain kinetic parameters for solid-state polymerization of poly(ethylene naphthalate) (PEN). An equation was developed to describe the relationships among time, temperature, and final molecular weight for PEN. The intrinsic viscosity and melting point during polymerization were used to monitor the molecular weight and the thermal stability of the resulting resins. The effect of moisture concentration on solid-state polymerization was also investigated. Hydrolytic degradation caused initial reductions of the molecular weight if prepolymers were solid-stated without being dried. With increased exposure to solid-state conditions, however, the hydrolytically degraded resin dried and repolymerized at rates similar to those samples that had undergone hydrolysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2055–2061, 2001     

Synthesis of high molecular weight poly(L‐lactic acid) via melt/solid polycondensation: Intensification of dehydration and oligomerization during melt polycondensation

Melt/solid state polycondensation (MP/SSP) is a cost‐effective route for synthesis of high molecular weight poly(L ‐lactic acid) (PLLA). However, the reaction rates in its four stages need to be enhanced greatly and the reaction times to be shortened largely before the MP/SSP technology can be industrialized. In this study, a new catalyst addition policy, i.e., adding TSA at the dehydration stage and SnCl₂·2H₂O at the MP stage, and more appropriate temperature and pressure programs were presented and applied in the MP process of LLA. The presence of TSA from dehydration appeared very effective for speeding up the dehydration and oligomerization stages as well as depressing racemization in the whole MP process. The polymerization degree (X_n) of oligomer was clearly increased, and the reaction time was shortened to a great extent. Direct using reduced pressure was also very helpful for intensifying the dehydration stage, only leading to LLA loss as little as 2%. A PLLA with M_w of 44,000 and optical purity of 96.8% suitable for subsequent SSP was produced after dehydration for 2 h, oligomerization for 2 h and MP for 4 h under appropriate conditions. And an interesting strong dependence of the M_w of final PLLA product on the X_n of the oligomer was observed. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Effects of tris(pentafluorophenyl)borane on the activation of zerovalent-nickel complex in the addition polymerization of norbornene

The effects of B(C₆F₅)₃ on the activation of the Ni(0) and Ni(II) complexes were studied in the polymerization of norbornene. The Ni(0) complex, such as bis(1,5-cyclooctadiene)nickel (Ni(COD)₂ (1), biacetylbis(2,6-diisopropylphenylimmine)(1,3-butadiene)nickel (2), or tetrakis(triphenylphosphine)nickel (5), in combination with B(C₆F₅)₃, was determined to have high activity in the polymerization of norbornene. On the other hand, the Ni(II) complex with B(C₆F₅)₃ did not provide any activity at all under analogous conditions regardless of the structure of the Ni(II) complex. The use of other borane compounds, such as B(C₆H₅)₃, BEt₃, and BF₃ etherate, with Ni(COD)₂ (1) in place of B(C₆F₅)₃ clearly showed the main functions of B(C₆F₅)₃. The high Lewis acidity of B(C₆F₅)₃ enabled it to activate catalytic complexes, thus inducing polymerization. The study of the ¹H, ¹³C, and ¹⁹F NMR spectra of the polynorbornene produced with Ni(COD)₂ (1) and B(C₆F₅)₃, in the presence or absence of ethylene, showed that the initiation of addition polymerization occurred through the insertion of the exo face of the norbornene into the Ni-C bond of the C₆F₅ ligand. A new polymerization mechanism was proposed in norbornene polymerization, wherein the active complex formed from Ni(COD)₂ (1) and B(C₆F₅)₃ acts as a catalyst.     

聚酯固相缩聚等温结晶特性的研究

聚酯(PET)固相缩聚(SSP)中切片的结晶性能及其演变影响固相缩聚反应,采用差示扫描量热仪(DSC)和热台偏光显微镜研究了固相缩聚反应前后PET切片的等温结晶特性。结果表明:PET切片在DSC中的等温结晶符合Avrami 方程,等温结晶温度升高,结晶速率常数K值减小,即结晶速率降低;热台偏光显微镜中不同等温结晶温度下形成了不同的球晶形态:黑十字消光图以及环形消光图;随着PET特性粘数(平均分子质量)增大,结晶速率常数K值减小,球晶生长速率减小,Avrami指数n值增大,形成更加复杂的消光图。对于固相缩聚前PET基础切片,球晶最大结晶速率在190℃左右。     

基于熔融/固相缩聚制备中高分子量聚乙醇酸

聚乙醇酸（PGA）通常可通过乙交酯开环聚合和乙醇酸熔融缩聚制得,但乙交酯开环聚合工艺复杂,导致PGA成本高。相较而言,乙醇酸熔融缩聚制备PGA工艺简单,成本较低,但难以获得中高分子量的PGA。因此,本文基于熔融/固相缩聚路线,系统研究了催化剂种类与含量、酯化温度、固相缩聚温度等聚合工艺条件对PGA外观形态、特性黏度和热稳定性的影响。发现三氟甲烷磺酸铋对乙醇酸熔融缩聚具有较好的催化效果,优化熔融/固相缩聚条件如下：催化剂含量为0.20%（质量）,酯化温度为180℃,熔融缩聚和固相缩聚温度为210℃,固相缩聚时间为12 h。在该熔融缩聚条件下,PGA的最高特性黏度为0.36 dl/g,进一步固相缩聚处理可以将PGA的特性黏度提高到0.59 dl/g。     

Catalytic Deoxygenative Reduction of Hydrazides to Hydrazines via B(C6F5)3-Catalyzed Hydrosilylation

The catalytic deoxygenative reduction of hydrazides to the corresponding alkyl hydrazine with PhSiH₃ via B(C₆F₅)₃-catalyzed hydrosilylation is reported. This metal-free protocol is compatible with various acylhydrazides and diacylhydrazides, giving rise to a variety of structurally diverse alkyl hydrazine products in 63–95% yields. The proper selection of borane catalyst and hydrosilane reductant is essential for catalysis. Mechanistic investigations reveal that the reaction involves a hydrazone intermediate.     

Synthesis and characterization of organosoluble poly(arylate‐imide)s prepared from direct polycondensation of bis(trimellitimide)‐diacids and various bisphenols

Three diimide‐diacids, 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]hexafluoropropane ( I‐A ), 2,2‐bis[4‐(4‐trimellitimidophenoxy)phenyl]propane ( I‐B ), and 5,5′‐bis[4‐ (4‐trimellitimidophenoxy)phenyl]hexahydro‐4,7‐methanoindan ( I‐C ), were prepared by the azeotropic condensation of trimellitic anhydride with three analogous diamines. Three series of alternating aromatic poly(arylate‐imide)s, having inherent viscosities of 0.41–0.82 dL/g, were synthesized from these diimide‐diacids ( I‐A , I‐B , and I‐C ) with various bisphenols by direct polycondensation using diphenyl chlorophosphate and pyridine as condensing agents. All of the polymers were readily soluble in a variety of organic solvents such as N‐methyl‐2‐pyrrolidone, N,N‐dimethylacetamide, and even in the less polar tetrahydrofuran. These polymers could be cast into transparent and tough films, which had strength at break values ranging from 73 to 98 MPa, elongation at break from 6 to 11%, and initial modulus from 1.6 to 2.2 GPa. The softening temperatures of the polymers were recorded at 145–248°C. They had 10% weight loss at a temperature above 450°C and left 35–51% residue even at 800°C in nitrogen. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3818–3825, 2003