新型高活性催化剂乙烯气相聚合的研究(Ⅰ)──气相均聚和共聚反应及气相均聚动力学

研究了新型高活性乙烯气相聚合催化剂TiCl₄/MgCl₂/ZnCl₂/SiCl₄/醇/Al(i-Bu)₃体系中钛和醇组分含量对聚合反应和产物颗粒形态的影响。测定了乙烯气相聚合反应动力学曲线,确定了聚合动力学方程。用SEM、DSC、WAXD、¹³CNMR对催化剂及聚合物的形态、结构和性能进行了分析和表征。     

双金属催化环氧化物聚合动力学研究

研究了双金属氰化络合催化剂DMC催化环氧丙烷聚合的动力学 .用测定反应过程体系压力变化来决定聚合的起始速率 ,发现聚合反应速率正比于催化剂用量C ,单体浓度M的平方 .该实验规律可以从单体参与链引发的动力学特点解释 .考察了温度对聚合反应速率的影响并求得了表观活化能为 5 9 1kJ·mol- 1 ,该值与环氧聚合的卟啉铝、稀土络合物等催化体系接近 .     

3—甲基丙烯酰胺基—9—乙基咔唑—过硫酸钾氧化还原体系引发 …

合成了可聚合芳香叔胺－３－甲基丙烯酰胺基－９－乙基咔唑,并与过硫酸钾组成氧化还原引发体系引发丙烯酰胺水溶液聚合,测定了聚合反应动力学,得到了超高分子量的聚丙烯酰胺。     

环氧乙烷环氧丙烷开环聚合反应动力学研究*

环氧乙烷和环氧丙烷由于具有较高的环张力,因而容易发生开环聚合。本文综述了环氧乙烷合环氧丙烷开环聚合反应的动力学研究进展,考察了环氧乙烷和环氧丙烷开环聚合反应的机理,分别讨论了各类催化剂体系中环氧乙烷和环氧丙烷开环聚合的动力学常数、两者的竞聚率及开环聚合产物的分子量分布,并指出了开环聚合反应动力学研究对于环氧乙烷和环氧丙烷的开环聚合研究及工业应用的重要性。     

甲基丙烯酸长链烷基酯的基团转移聚合研究

进行了甲基丙烯酸长链烷基酯（庚、辛、壬酯的混合物）的基团转移聚合．得到了具有较高分子量和转化率．分子量分布较窄的聚合产物．研究了聚合条件对产物的分子量及分布，转化率，聚合速率的影响．探讨了聚合反应动力学．认为聚合体系的非极性不利于催化剂的离解，单体较大的空间障碍使扩散困难．均是表观活化能升高和转化难以完全的原因．发现此类单体的基团转移聚合对温度的依赖性极大，本体聚合无自加速现象，容易得到较高的分子量．     

以聚丙二醇二苯甲酸酯为给电子体的丙烯聚合催化剂

 采用聚丙二醇二苯甲酸酯(PPGDB)为内给电子体制备了一种新的丙烯聚合催化剂MgCl2/PPGDB/TiCl4. 该催化剂用于丙烯聚合时,除了具有与以邻苯二甲酸二异丁酯为给电子体的催化剂相当的活性和立体定向性外,其特点在于所得产物的分子量分布较宽(Mw/Mn＞8.0). 采用红外光谱研究了催化剂中PPGDB与MgCl2的作用机制,结果表明PPGDB中的酯官能团和醚官能团可同时与MgCl2配位. 这种双官能团的配位作用是所得聚合物分子量分布较宽的主要原因.     

新型高活性催化剂乙烯气相聚合的研究（I）：气相均聚和共聚…

研究了新型高活性乙烯气相聚合催化剂ＴｉＣｌ４／ＭｇＣｌ２／ＺｎＣｌ２／ＳｉＣｌ４／醇／Ａｌ（ｉ－Ｂｕ）３体系中钛和醇组分含量对聚合反应和产物颗粒形态的影响。测定了乙烯气相聚合反应动力学曲线，确定了聚合动力学方程。用ＳＥＭ，ＤＳＣ，ＷＡＸＤ，＾１＾３ＣＮＭＲ对催化剂及聚合物的形态，结构和性能进行了分析和表征。     

调节剂存在下双金属氰化络合催化剂催化环氧丙烷聚合的动力学

研究了双金属氰化络合催化剂DMC催化环氧丙烷调节聚合的动力学 .通过测定反应过程体系压力的变化来决定聚合的起始速率 ,发现聚合反应速率与分子量调节剂浓度Tr的线性函数的 - 1次方成正比 .考察了DMC催化剂在反应不同阶段的远红外吸收变化 ,提出了聚合反应可能的反应历程 ,并推导出调节聚合的动力学方程 .研究结果表明调节聚合的动力学特点在于链引发是发生在催化剂与单体之间 ,而不是催化剂与调节剂之间     

5,6-苯并-2-亚甲基-1,3-二氧环庚烷的活性自由基开环聚合反应

活性 (或称可控 )自由基聚合研究是目前高分子科学的研究热点之一[1～ 8] .活性自由基聚合制备的聚合物具有分子量随转化率提高而线性增加、分子量分布窄和聚合反应为一级反应动力学等特点 .自由基开环聚合所得产物体积收缩小 ,某些含有不饱和双键的螺环单体发生双开环聚合时甚至发生体积膨胀 ;开环聚合还可在聚合物主链上引入各种官能团 ,如酯基、碳酸酯基、酮基等 [9～ 12 ] .因此 ,用活性聚合的方法对自由基开环聚合的分子量和分子量分布进行控制 ,可以制备出具有各种不同结构和性能的新聚合物 . Wei等 [13] 报道了利用稳定自由基法实现…     

反相悬浮聚合法制备球状卡波树脂的研究

以偶氮二异丁脒盐酸盐(V50)作为引发剂,失水山梨醇硬脂酸酯(Span60)和聚二甲基硅氧烷PEG-7磷酸酯为复合分散剂,蔗糖烯丙基醚和三甲基丙基聚氧乙烯(15)醚三丙烯酸酯为复合交联剂,丙烯酸为单体,正已烷为反应介质,采用反相悬浮聚合方法制备了球状卡波树脂.用光学显微镜和扫描电镜分别对聚合反应的成粒过程和产物的形貌进行了研究.结果表明,聚合体系呈现典型的悬浮聚合相态特征,并获得了堆积密度较高(0.65 g/cm3)的球状卡波树脂.聚合反应动力学研究结果表明,该反相悬浮聚合的聚合速率对单体浓度和引发剂浓度的反应级数分别约为1.36和0.70;聚合反应的表观活化能为78.0 kJ/mol.交联剂对卡波树脂的性能有重要的影响,通过适度交联可提高产物的增稠效率及其抗剪切性能.     

Synthesis of titanium(IV) complexes that contain the Bis(silylamide) ligand of the type [1,8-C10H6(NR)2], and alkene polymerization catalyzed by [1,8-C10H6(NR)2]TiCl2-cocatalyst system

[1,8-C₁₀H₆(NR)₂]TiCl₂ (3; R=SiMe₃, SiⁱBuMe₂, SiⁱPr₃) complexes have been prepared from dilithio salts [1,8-C₁₀H₆(NR)₂]Li₂ (2) and TiCl₄ in diethyl ether in moderate yields (60–63%). These complexes showed significant catalytic activities for ethylene polymerization and for ethylene/1-hexene copolymerization in the presence of methylaluminoxane (MAO), methyl isobutyl aluminoxane (MMAO), AlⁱBu₃– or AlEt₃–Ph₃CB(C₆F₅)₄ as a cocatalyst. The catalytic activities performed in heptane (cocatalyst MMAO) were higher than those carried out in toluene (cocatalyst MAO): 709 kg-PE/mol-Ti·h could be attained for ethylene polymerization by using [1,8-C₁₀H₆(NSiⁱBuMe₂)₂]TiCl₂–MMAO catalyst system.     

Metallorganische lewissäuren : XX. Reaktionen von (π-C5H5)(CO)2LM-X (L = CO, PR3; M = Mo, W; X = BF4, PF6, AsF6, SbF6) mit Schwefel-haltigen liganden

The compounds (π-C₅H₅)(CO)₂LM-X (L = CO, PR₃; M = Mo, W; X = BF₄, PF₆, AsF₆, SbF₆) react with H₂S, p-MeC₆H₄SH, Ph₂S and Ph₂SO(L′) to give ionic complexes [(π-C₅H₅)(CO)₂LML′]⁺ X⁻. Also sulfur-bridged complexes, [(π-C₅H₅)(CO)₃W---SH---W(CO)₃(π-C₅H₅)]⁺ AsF₆⁻ and [(π-C₅H₅)(CO)₃M-μ-S₂C=NCH₂Ph-M(CO)₃(π-C₅H₅)], have been obtained. Reactions with SO₂ and CS₂ have been examined.     

Polymerization of MMA by oscillating zirconocene catalysts, diastereomeric zirconocene mixtures, and diastereospecific metallocene pairs

Characteristics of methyl methacrylate (MMA) polymerization using oscillating zirconocene catalysts, (2-Ph-Ind)₂ZrX₂ (X = Cl, 1; X = Me, 2), mixtures of rac- and meso-zirconocene diastereomers, (SBI)ZrMe₂ [3, SBI = Me₂Si(Ind)₂] and (EBI)ZrMe₂ [4, EBI = C₂H₄(Ind)₂], as well as diastereospecific metallocene pairs, rac-4/Cp₂ZrMe₂ (5) and rac-4/CGCTiMe₂ [6, CGC = Me₂Si(Me₄C₅)(t-BuN)], are reported. MMA polymerization using the chloride catalyst precursor 1 activated with a large excess of the modified methyl aluminoxane is sluggish, uncontrolled, and produces atactic PMMA. On the other hand, the polymerization by a 2/1 ratio of 2/B(C₆F₅)₃ or 2/Ph₃CB(C₆F₅)₄ is controlled and produces syndiotactic PMMA. Mixtures of diastereomeric ansa-zirconocenes 3 or 4 containing various rac/meso ratios, when activated with B(C₆F₅)₃, yield bimodal PMMA; this behavior is attributed to the meso-diastereomer that, in its pure form, affords bimodal, syndio-rich atactic PMMA. For MMA polymerization using diastereospecific metallocene pairs, rac-4/5 and rac-4/6, the isospecific catalyst site dominates the polymerization events under the conditions employed in this study, and the aspecific and syndiospecific sites are largely nonproductive, thereby forming only highly isotactic PMMA.     

Synthesis and structure of ansa-cyclopentadienyl pyrrolyl titanium complexes: [(η-C5H4)CH2(2-C4H3N)]Ti(NMe2)2 and [1,3-{CH2(2-C4H3N)}2(η-C5H3)]Ti(NMe2)

Reaction of ansa-cyclopentadienyl pyrrolyl ligand (C₅H₅)CH₂(2-C₄H₃NH) (2) with Ti(NMe₂)₄ affords bis(dimethylamido)titanium complex [(η⁵-C₅H₄)CH₂(2-C₄H₃N)]Ti(NMe₂)₂ (3) via amine elimination. A cyclopentadiene ligand with two pendant pyrrolyl arms, a mixture of 1,3- and 1,4-{CH₂(2-C₄H₃NH)}₂C₅H₄ (4), undergoes an analogous reaction with Ti(NMe₂)₄ to give [1,3-{CH₂(2-C₄H₃N)}₂(η⁵-C₅H₃)]Ti(NMe₂) (5). Molecular structures of 3 and 5 have been determined by single crystal X-ray diffraction studies.     

New organogold(I) complexes: Synthesis, structure, and dynamic behavior of the polynuclear organogold diphenylmethane and diphenylethane derivatives

Two organogold derivatives of diphenylmethane and diphenylethane, Ph₃PAu(o-C₆H₄)CH₂(C₆H₄-o)AuPPh₃ (1) and Ph₃PAu(o-C₆H₄)(CH₂)₂(C₆H₄-o)AuPPh₃ (2), have been synthesized by the reaction of ClAuPPh₃ with Li(o-C₆H₄)CH₂(C₆H₄-o)Li and Li(o-C₆H₄)(CH₂)₂(C₆H₄-o)Li respectively. The interaction of 1 with dppe results in the replacement of the two PPh₃ groups to give a macrocyclic compound (3) that includes an Au Au bond. Compounds 1 and 2 react with one or two equivalents of [Ph₃PAu]BF₄ to form new types of cationic complex [CH₂(C₆H₄-o)₂(AuPPh₃)₃]BF₄ (4), [CH₂(C₆H₄-o)₂(AuPPh₃)₄](BF₄)₂ (5), and [(CH₂)₂(C₆H₄-o)₂(AuPPh₃)₄](BF₄)₂ (6). Complexes 1–6 have been characterized by X-ray diffraction studies, FAB MS, and IR as well as by ¹H and ³¹P NMR spectroscopy. A complicated system of Au H-C agostic interactions, involving the bridging alkyl groups (—CH₂— and CH₂-CH₂—) of diphenylmethane and diphenylethane ligands, has been found to occur in complexes 1–3 and 6.     

Macrocyclic gold(I) complexes and [2]catenanes containing carbonyl functionalized diacetylide ligands

The carbonyl derivatized bis(alkyne) O=C(4-C₆H₄OCH₂CCH)₂ was converted into the imine derivatives RN=C(4-C₆H₄OCH₂CCH)₂ [R=OH, NHC(O)NH₂, NHC₆H₃-2,4-(NO₂)₂] and into the 4-bromomethyl-1,3-dioxolane derivative BrCH₂C₂H₃O₂C(4-C₆H₄OCH₂CCH)₂. The alkyne units in these compounds react with [AuCl(SMe₂)] in the presence of base to form the corresponding digold(I) diacetylide complexes, that exist as insoluble oligomers or polymers. They reacted with the diphosphines Ph₂PZPPh₂ [Z=CC, trans-HC=CH and (CH₂)_n, n=3–5] to give macrocyclic gold(I) complexes of the type [Au₂(μ-LL)(μ-PP)], where LL is the diacetylide and PP the diphosphine ligand. The ability of these macrocyclic complexes to self-assemble to [2]catenanes has been studied. The ketone and imine derivatives do not form [2]catenanes because the orientation of the aryl groups is unfavorable, but the 1,3-dioxolane derivatives may catenate if the ring size is optimum.     

Arylkomplexe des typs trans-[Ir(Ar)(CO)(PPh3)2]

The preparation and properties as well as some reactions of a series of arylcarbonylbis(triphenylphosphine)iridium(I) complexes [Ir(Ar)(CO)(PPh₃)₂] (Ar = C₆H₅, C₆F₅, 2-C₆H₄CH₃, 3-C₆H₄CH₃, 4-C₆H₄CH₃, 2-C₆H₄OCH₃, 2,6-C₆H₃-(OCH₃)₂, 4-C₆H₄N(CH₃)₂, 3-C₆H₄Cl, 4-C₆H₄Cl, 4-C₆H₄Cl, 3-C₆H₄CF₃, 4-C₆H₄CF₃) are described, and the most important IR data as well as the ³¹P NMR parameters of these, without exception trans-planar, compounds are given.

Some of the complexes react with molecular oxygen to form well defined dioxygen adducts [Ir(Ar)(O₂)(CO)(PPh₃)₂] (Ar = C₆H₅, 3-C₆H₄CH₃, 4-C₆H₄CH₃). Complexes with ortho-substituted aryl ligands are not oxygenated. This effect is referred to as a steric shielding of the metal center by the corresponding ortho-substituents. With SO₂ the similar irreversible addition compound [Ir(4-C₆H₄CH₃)-(SO₂)(CO)(PPh₃)₂] is obtained. Sulfur dioxide insertion into the Ir---C bond cannot be observed.

The first step of the reaction between [Ir(4-C₆H₄CH₃)(CO)(PPh₃)₂] and hydrogen chloride involves an oxidative addition of HCl to give [Ir(H)(Cl)(4-C₆-H₄CH₃)(CO)(PPh₃)₂]. Ir---C bond cleavage by reductive elimination of toluene from the primary adduct does not occur except at elevated temperature.     

Synthesis and properties of alkyldicyclopentadienyl-vanadium(III) compounds

The compounds Cp₂VR (R = CH₃, C₂H₅, n-C₃H₇, n-C₄H₉, n-C₅H₁₁, CH₂C(CH₃)₃ or CH₂Si(CH₃)₃) have been prepared from Cp₂ VCl and RMgX in n-pentane. The air-sensitive compounds are stable at room temperature, but decompose between 65 and 138°C. The thermal stability decreases in the order R = CH₃ CH₂Si(CH₃)₃ > C₂H₅ > CH₂C(CH₃)₃ > n-C₅H₁₁ > n-C₄H₉ > n-C₃H₇. Compounds with R = i-C₃H₇ or t-C₄H₉ could not be obtained.     

ansa-Metallocene derivatives XXXIII. 2-Dimethylamino-substituted bis-indenyl zirconium dichloride complexes with and without a dimethylsilyl bridge: syntheses, crystal structures and properties in propene polymerization catalysis

Bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (2-(CH₃)₂N-C₉H₆)₂ZrCl₂, and dimethylsilyl-bridged bis(2-N,N-dimethylamino-indenyl) zirconium dichloride, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂, were prepared by reaction of the corresponding ligand lithium salts with ZrCl₄ in toluene. Diffractometric structure determinations reveal C₂-symmetric complex geometries for both complexes. An increased electron density at the Zr center of the dimethylamino-substituted complexes is indicated by reduction potentials which are 0.3–0.4 V more negative than those of their unsubstituted analogs. When activated with methyl aluminoxane in toluene solution, (CH₃)₂Si(2-(CH₃)₂N-C₉H₅)₂ZrCl₂ catalyzes the polymerization of propene to polymers with a microstructure comparable with that of polymers produced with other Me₂Si-bridged bis(indenyl)ZrCl₂ complexes, but with a substantially increased fraction of i-propyl end groups derived from alkyl exchange between Zr-polymer and Al---Me species.     

Synthesis of metallocenes of zirconium, hafnium, manganese, iron, tin, lead and half-sandwich complexes of rhodium and iridium containing the ligands (η-C5R4CR′2PMe2), where R and R′ may be H or Me

The dimethylphosphino substituted cyclopentadienyl precursor compounds [M(C₅Me₄CH₂PMe₂)], where M=Li⁺ (1), Na⁺ (2), or K⁺ (3), and [Li(C₅H₄CR′₂PMe₂)], where R′₂=Me₂ (4), or (CH₂)₅ (5), [HC₅Me₄CH₂PMe₂H]X, where X⁻=Cl⁻ (6) or PF₆⁻ (7) and [HC₅Me₄CH₂PMe₂] (8), are described. They have been used to prepare new metallocene compounds, of which representative examples are [Fe(η-C₅R₄CR′₂PMe₂)₂], where R=Me, R′=H (9); R=H and R′₂=Me₂ (10), or (CH₂)₅ (11), [Fe(η-C₅H₄CMe₂PMe₃)₂]I₂ (12), [Fe{η-C₅Me₄CH₂P(O)Me₂}₂] (13), [Zr(η-C₅R₄CR′₂PMe₂)₂Cl₂], where R=H, R′=Me (14), or R=Me, R′=H (15), [Hf(η-C₅H₄CMe₂PMe₂)₂]Cl₂] (16), [Zr(η-C₅H₄CMe₂PMe₂)₂Me₂] (17), {[Zr(η-C₅Me₄CH₂PMe₂)₂]Cl}{(C₆F₅)₃BClB(C₆F₅)₃} (18), [Zr{(η-C₅Me₄CH₂PMe₂)₂Cl₂}PtI₂] (19), [Mn(η-C₅Me₄CH₂PMe₂)₂] (20), [Mn{(η-C₅Me₄CH₂PMe₂B(C₆F₅)₃}₂] (21), [Pb(η-C₅H₄CMe₂PMe₂)₂] (23), [Sn(η-C₅H₄CMe₂PMe₂)₂] (24), [Pb{η-C₅H₄CMe₂PMe₂B(C₆F₅)₃}₂] (25), [Pb(η-C₅H₄CMe₂PMe₂)₂PtI₂] (26), [Rh(η-C₅Me₄CH₂PMe₂)(C₂H₄)] 29, [M(η,κP-C₅Me₄CH₂PMe₂)I₂], where M=Rh (30), or Ir, (31).