柄型金属有机化合物（Ⅴ）——锗桥连茚基及取代茚基锆合物的合成及催化烯烃聚合

锗桥连茚及取代茚配体相继与丁基锂及ZrCl4作用，生成锗桥连茚基及取代茚基锆化合物Me2Ge(2-R^1-4-R^2-Ind)2ZrCl2[R^1=R^2=H(1);R^1=Me,R^2=H(2);R^1=Me,R^2=Ph(3)]。化合物1－3均为内消旋和外消旋异异构体的混合物，通过多次重结晶得到化合物1和2的纯外消旋异构体及化合物3的内消旋异构体。由元素分析和^1H NMR谱表征了化合物的分子结构。研究了在甲基铝氧烷（MAO）的助催化下，化合物1－3对乙烯和丙烯聚合的催化性能。由锗桥连茚基化合物1－3得到的聚乙烯的分子量分布比一般茂金属催化剂略宽，内消旋和外消旋异构体的混合物（3）由于两个催化活性中心不等同而使得到的聚乙烯的分子量分布相当宽。外消旋异构体1和2催化丙烯聚合得到高等规聚丙烯。     

柄型金属有机化合物(Ⅴ)——锗桥连茚基及取代茚基锆化合物的合成及催化烯烃聚合

锗桥连茚及取代茚配体相继与丁基锂及ZrCl4作用, 生成锗桥连茚基及取代茚基锆化合物Me2Ge(2-R1-4-R2-Ind)2ZrCl2[R1= R2= H(1); R1= Me, R2= H(2); R1= Me, R2= Ph(3)]. 化合物 1-3均为内消旋和外消旋异构体的混合物, 通过多次重结晶得到化合物1和2的纯外消旋异构体及化合物3的内消旋异构体. 由元素分析和 1H NMR 谱表征了化合物的分子结构. 研究了在甲基铝氧烷(MAO)的助催化下, 化合物1-3对乙烯和丙烯聚合的催化性能. 由锗桥连茚基化合物1-3得到的聚乙烯的分子量分布比一般茂金属催化剂略宽. 内消旋和外消旋异构体的混合物(3)由于两个催化活性中心不等同而使得到的聚乙烯的分子量分布相当宽. 外消旋异构体1和2催化丙烯聚合得到高等规聚丙烯.     

柄型金属有机化合物（Ⅱ）：硅氧硅桥联二（1—茚基及四氢茚基…

１，３－二（１－茚基）四甲基二硅氧烷相继与丁基锂及ＺｒＣｌ４．２ＴＨＦ作用，生成硅氧桥联二（１－茚基）二氯化锆（Ｍｅ２ＳｉＯＳｉＭｅ２）（Ｉｎｄ）２ＺｒＣｌ２（１）。对其进行催化氢化得到相应的四氢茚基化合物（Ｍｅ２ＳｉＯＳｉＭｅ２）ＩｎｄＨ４）２ＺｒＣｌ２（２）．１和２均含有顺式和反式二种异构体（１和１以及２和２），通过重结晶得到纯的单一异构体，１，２和２，１和２的晶体结构经Ｘ射线衍射测定，二者均     

柄型金属有机化合物（Ⅳ）：四甲基二硅桥连取代环戊二烯？…

四甲基二硅桥连取代环戊二烯基配体相继与丁基锂及ＭＣ１４。２ＴＨＦ作用,生成四甲基二硅桥连取代环戊二烯基钛和锆化合物（Ｍｅ２ＳｉＳｉＭｅ２）（Ｃ５Ｈ４Ｒ）（Ｃ５Ｈ４Ｒ１）ＭＣ１２「Ｒ＝Ｈ,Ｒ１＝ｔ－Ｂｕ,Ｍ＝Ｔｉ（１）,Ｚｒ（２）,Ｈｆ（３）;Ｒ＝Ｈ,Ｒ１＝Ｍｅ,Ｍ＝Ｔｉ（４）;Ｒ＝Ｒ１＝Ｍｅ,Ｍ＝Ｔｉ（５）,Ｚｒ（６）」。通过元素分析、ＭＳ和Ｈ１ＮＭＲ谱表征了化合物的分了结构,并通过Ｘ射线衍射分析     

柄型茂金属化合物（Ⅲ）

１,２－二（１－茚基）四甲基二硅烷相继与本基锂及ＭＣｌ４·２ＴＨＦ作用。生成四甲基二硅桥连二（１－茚基）钛和锆化合物（Ｍｅ２ＳｉＳｉＭｅ２）「Ｉｎｄ」２ＣＭｌ２「Ｍ＝（Ｔｉ（１）,Ｚｒ（２）」,对其进行催化氢化,得到相应的四氢茚基化合物（Ｍｅ２ＳｉＳｉＭｅ２）「ＩｎｄＨ４」２ＭＣｌ２「Ｍ＝Ｔｉ（３）,Ｚｒ（４）」通过元素分析,ＭＳ和ＨＮＭＲ谱表征了化合物的分子结构,并了在ＭＡＯ的助催化下,化合物３     

柄型金属有机化合物（Ⅱ）──硅氧硅桥联二（1－茚基及四氢茚基）二氯化锆的合成和结构

１，３－二（１－茚基）四甲基二硅氧烷相继与丁基锂及ＺｒＣｌ_４·２ＴＨＦ作用，生成硅氧硅桥联二（１－茚基）二氯化锆（Ｍｅ_２ＳｉＯＳｉＭｅ_２）［Ｉｎｄ］_２ＺｒＣｌ_２（１）。对其进行催化氢化得到相应的四氢茚基化合物（Ｍｅ_２ＳｉＯＳｉＭｅ_２）［ＩｎｄＨ_４］_２ＺｒＣｌ_２（２）。１和２均含有顺式和反式二种异构体（１_ｃ和１_ｔ以及２_ｃ和２_ｔ），通过重结晶得到纯的单一异构体１_ｔ、２_ｃ和２_ｔ，１_ｃ和２_ｔ的晶体结构经Ｘ射线衍射测定，二者均属单斜晶系，Ｐ２_１／ｎ（１_ｔ）和Ｐ２_１／ｃ（２ｃ）空间群，其中２_ｃ分子的一个配体六元环在晶胞中具有两种几率完全相等的不同构象。     

（四甲基二硅撑）二（3－三甲硅基环戊二烯基）四羰基二铁及其相关化合物的合成及结构

１，２－二（三甲硅基环戊二烯基）四甲基二硅烷与Ｆｅ（ＣＯ）_５在二甲苯中于１０５～１１０℃反应除分离到少量标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２（５）外，主要是生成了脱Ｍｅ_３Ｓｉ基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η－Ｃ_５Ｈ_４Ｆｅ（ＣＯ）］_２（μ－ＣＯ）_２（１）及１的热重排异构体［Ｍｅ_２ＳｉＣ５Ｈ４－Ｆｅ（ＣＯ）_２］_２（２）．将５的二甲苯溶液加热回流１８ｈ，则转化为其异构体［Ｍｅ_２Ｓｉ（Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２（６）．脱硅基发生在由相应反应物制备５的过程中。且脱硅基是与反应物中（Ｍｅ_２ＳｉＳｉＭｅ_２）桥的存在有关．５的晶体结构经Ｘ射线衍射测定属单斜晶系，Ｐ２_１／ｍ空间群，晶体学数据：ａ＝０．６７８０（１）ｎｍ，ｂ＝２．２３０３（９）ｎｍ，ｃ＝０．９９８８（１）ｎｎ，；β＝９８．９６（１）°，Ｖ＝１．４９６０ｎｍ~３．Ｚ＝２，Ｄ_ｃ＝１．３６ｇ／ｃｍ~３．     

三羰基环戊二烯基钼负离子与1,3—二卤丙烷的反应

三羰基环戊二烯基钼负离子与１，３－二卤丙烷在一缩二乙二醇二甲醚介质中反应，生成环卡宾配合物ＣｐＭｏＸ（ＣＯ２）ＣＯ（ＣＨ２）２ＣＨ２（Ｘ＝Ｂｒ．Ｉ）硅桥连双环戊二烯基三羰基钼负离子与１，３－二卤丙烷顺利地进行类似反应，生成相应的硅桥连双（环卡宾钼配合物）－Ｅ（Ｃ５Ｈ１ＭｏＸ（ＣＯ）２ＣＯ（ＣＨ２）２ＣＨ２）２（Ｅ＝Ｍｅ２Ｓｉ，Ｍｅ２ＳｉＳｉＭｅ２，Ｍｅ２ＳｉＯＳｉＭｅ２），化合物硅氧硅桥联二茂二钼     

（四甲基二硅撑）双（3－三甲硅基环戊二烯基）－四羰基二铁的反应性

标题化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２／（μ－ＣＯ）_２（Ａ）分子中的Ｆｅ－Ｆｅ键被钠汞齐还原断裂，生成相应的双铁负离子，分别与ＭｅＣＯＣｌ、ＰｈＣＯＣｌ、ＰｈＣＨ_２Ｃｌ、ＣｌＣＨ_２ＣＯＯＣ_２Ｈ_５和Ｐｈ_３ＳｎＣｌ进行亲核取代反应，生成在铁原子上引入相应取代基的产物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２Ｒ］_２（Ｒ：ＭｅＣＯ（１），ＰｈＣＯ（２），ＰｈＣＨ_２（３），ＣＨ_２ＣＯＯＣ_２Ｈ_５（４），Ｐｈ_３Ｓｎ（５），Ｉ（６））。Ａ在氯仿中与碘反应，得到Ｆｅ－Ｆｅ断裂的双铁碘化物，但在苯中与过量碘反应，则得到Ｆｅ－Ｉ－Ｆｅ桥联的离子型化合物（Ｍｅ_２ＳｉＳｉＭｅ_２）［η￣５－（３－Ｍｅ_３ＳｉＣ_５Ｈ_３）Ｆｅ（ＣＯ）_２］_２Ｉ·Ｉ（７）。化合物６的晶体和分子结构经Ｘ射线衍射测定，６属单斜晶系，Ｐ２１／ｃ空间群，ａ＝１．７２１７（４）ｎｍ，ｂ＝０．７７５３（２）ｎｍ，Ｃ＝１．３６２９（７）ｎｍ，β＝１０３．８０（３）°，Ｖ＝１．７６７（２）ｎｍ３，Ｚ＝４，Ｄｃ＝１．６２９９·ｃｍ－１，最终偏差因子Ｒ＝０．０５４。     

含1-(2-甲氧乙基)茚基和二(三甲硅基)胺基的稀土有机配合物的合成和表征

无水三氯化稀土（ＬｎＣｌ３），二（三甲硅基）胺基钾（ＬｉＮ（ＳｉＭｅ３）２〗及１－（２－甲乙基）茚室温上在四氢呋喃溶剂中反应，得到了４个含１－（２－甲氧乙基）茚基和二（三甲硅基）胺基的稀土金属有机物｛（Ｃ９Ｈ６ＣＨ２Ｃ２ＯＭｅ）Ｌｎ〖Ｎ（ＳｉＭｅ３）２〗２（Ｌｎ＝Ｎｄ，Ｓｍ，Ｄｙ，Ｙｂ）｝，这些配合物均经元素分析、ＩＲ和ＭＳ表征。     

Indenyl zirconium dinitrogen chemistry: N2 coordination to an isolated zirconium sandwich and synthesis of side-on, end-on dinitrogen compounds

Exposure of the isolable zirconocene sandwich compounds, (eta(5)-C5Me5)(eta(5)-C9H5-1-R(1)-3-R(2))Zr (R(1) = Me, (i)Pr, (t)Bu; R(2) = Me) to one atmosphere of dinitrogen resulted in N2 coordination. X-ray diffraction and NMR spectroscopy establish that the resulting dimeric dinitrogen compounds contain an unusual mu2,eta(2)-bridging indenyl ring and a weakly activated N2 ligand. N2 coordination from the isolable zirconium sandwich compounds is extremely sensitive to the number and size of the indenyl subsituents. Compounds bearing two [(i)Pr] or three methyl substituents are stable as eta(9) sandwich compounds for weeks under dinitrogen likely due to the inability to dimerize through a two-atom N2 bridge. Performing the reduction of (eta(5)-C5Me5)(eta(5)-C9H5-1-R(1)-3-R(2))ZrCl2 (R(1) = (i)Pr, (t)Bu; R(2) = Me; R(1) = R(2) = SiMe3) under an N2 atmosphere produced a different outcome; rare examples of side-on, end-on zirconium dinitrogen compounds were isolated and in one case, crystallographically characterized. Protonolysis studies with weak Br?nsted acids were used to evaluate the relative activation of the bridging dinitrogen ligands.     

Half-zirconocene anilide complexes: synthesis, characterization and catalytic properties for ethylene polymerization and copolymerization with 1-hexene

A number of half-zirconocene anilide complexes of the type Cp*ZrCl(2)[N(2,6-R(1)(2)C(6)H(3))R(2)] [R(1) = (i)Pr (1, 3), Me (2); R(2) = Me (1, 2), Bn (3)] and Cp*ZrCl[N(2,6-Me(2)C(6)H(3))Me](2) (4) (Cp* = pentamethylcyclopentadienyl) were synthesized from the reactions of Cp*ZrCl(3) with the lithium salts of the corresponding anilide in diethyl ether at room temperature. All new zirconium complexes were characterized by (1)H and (13)C NMR and elemental analysis. Molecular structures of complexes 1, 2 and 4 were determined by single crystal X-ray diffraction analysis. Upon activation with Al(i)Bu(3) and Ph(3)CB(C(6)F(5))(4), complexes 1-4 exhibit good catalytic activity for ethylene polymerization, and produce polyethylene with a moderate molecular weight. Among these zirconium complexes, complex 1 shows the highest catalytic activity while complex 4 shows the lowest catalytic activity for ethylene polymerization. Complexes 1-3 also exhibit moderate catalytic activity for copolymerization of ethylene with 1-hexene, and produce copolymers with relatively high molecular weight and reasonable 1-hexene incorporation. In addition, the activation procedure of these catalyst systems were studied by (1)H NMR spectroscopy.     

取代茚基二价稀土配合物催化己内酯开环聚合反应

研究了1-环戊烷基茚基二价镱配合物(1-C5H9C9H6)2Yb(THF)2作为单组分催化剂催化己内酯开环聚合反应, 考察了催化剂用量、聚合反应时间、聚合反应温度对己内酯聚合反应的影响. 结果表明, 配合物(1-C5H9C9H6)2Yb(THF)2对己内酯聚合有较高的催化活性; 温度升高, 聚合反应的转化率增加, 但产物的数均分子量及分子量分布无明显变化; 所得聚合物分子量分布较窄. 其它几种取代茚基稀土配合物也显示出较高的催化活性, 其活性有下列次序: (1-C2H5C9H6)2Sm(THF)2>(1-C5H9C9H6)2Sm(THF)>KSm(1-C5H9C9H6)3(THF)3>(1-PhCH2C9H6)2Sm(THF)2>(1-C5H9C9H6)2Yb(THF)2, 二价钐配合物较二价镱配合物具有较高的催化活性. 通过凝胶渗透色谱法测定了聚合产物的数均分子量及其分布.     

Synthesis and Catalytic Application of Homo-bimetallic Metallocene Complexes as Ethylene Polymerization Catalysts

ＩｎｔｒｏｄｕｃｔｉｏｎＩｔｉｓｗｅｌｌｋｎｏｗｎｔｈａｔｍｅｔａｌｌｏｃｅｎｅｓａｃｔｉｖａｔｅｄｗｉｔｈｍｅｔｈｙｌａｌｕｍｉｎｏｘａｎｅ (ＭＡＯ)ａｒｅｈｉｇｈｌｙａｃｔｉｖｅｈｏｍｏｇｅｎｅｏｕｓＺｉｅｇｌｅｒ Ｎａｔｔａｃａｔａｌｙｓｔｓｔｈａｔｐｒｏｄｕｃｅｐｏｌｙｏｌｅｆｉｎｗｉｔｈｃｏｎ ｔｒｏｌｌｅｄｓｔｅｒｅｏｒｅｇｕｌａｒｉｔｙａｎｄｎａｒｒｏｗｍｏｌｅｃｕｌａｒｗｅｉｇｈｔｄｉｓｔｒｉ ｂｕｔｉｏｎ ,1 4 ｈｏｗｅｖｅｒ,ｔｈｅｍｏｌｅｃｕｌａｒｗｅｉｇｈｔｏｆｔｈｅｐｏｌｙｍ…     

2-[1-(2,6-Dibenzhydryl-4-methylphenylimino)ethyl]-6-[1-(arylimino)ethyl]pyridylcobalt(II) dichlorides: synthesis, characterization and ethylene polymerization behavior

A series of unsymmetrical 2,6-bis(imino)pyridylcobalt(II) complexes, {2-[2,6-(CH(C(6)H(5))(2))(2)-4-Me-C(6)H(2)N==C(CH(3))]-6-(2,6-R(1)(2)-4-R(2)-C(6)H(2)N==CCH(3))-C(5)H(3)NCoCl(2)} where R(1) = Me, Et or (i)Pr, R(2) = H or Me, together with the new symmetrical complex 2,6-[2,6-(CH(C(6)H(5))(2))(2)-4-Me-C(6)H(2)N==C(CH(3))](2)-C(5)H(3)NCoCl(2), were synthesized. All of the compounds were fully characterized by (1)H NMR and IR spectroscopy, as well as by elemental analysis. The molecular structures of Co1 (R(1) = Me, R(2) = H) and Co5 (R(1) = Et, R(2) = Me) were further confirmed by single crystal X-ray diffraction, which indicated that the cobalt centres were penta-coordinate with a pseudo square-pyramidal geometry. Upon treatment with MAO or MMAO, these cobalt pre-catalysts exhibited higher activities than any previously reported cobalt pre-catalysts, with values as high as 4.64 × 10(6) g PE mol(-1)(Co) h(-1) for ethylene polymerization at atmospheric pressure. The polyethylenes obtained were of high molecular weight and narrow molecular weight distribution.     

Titanium isopropoxide complexes of a series of sterically demanding aryloxo based [N2O2]2- ligands as precatalysts for ethylene polymerization

Several titanium isopropoxide complexes [N,N'-bis(2-oxo-3-R(1)-5-R(2)-phenylmethyl)-N,N'-bis(methylene-p-R(3)-C(6)H(4))-ethylenediamine]Ti(O(i)Pr)(2) [R(1) = t-Bu, R(2) = Me, R(3) = H (1b); R(1) = R(2) = t-Bu, R(3) = H, (2b); R(1) = R(2) = Cl, R(3) = H, (3b), R(1) = t-Bu, R(2) = Me, R(3) = Cl (4b); R(1) = R(2) = t-Bu, R(3) = Cl, (5b); R(1) = R(2) = R(3) = Cl, (6b)] supported over sterically demanding aryloxy based [N(2)O(2)]H(2) ligands have been designed as precatalysts for the ethylene polymerization. Specifically, the 1b-6b complexes, when treated with methylaluminoxane (MAO) under 88 ± 0.5 psi of ethylene at 30 °C for 3 h, produced polyethylene polymers of high molecular weight (M(w) = ca. 7.2-8.3 × 10(5) g mol(-1)) having broad molecular weight distribution (PDI = ca. 13.1-14.6). The 1b-6b complexes were conveniently synthesized from the direct reaction of the [N(2)O(2)]H(2) ligands, 1a-6a, with Ti(O(i)Pr)(4) in 69-86% yield.     

含有烯丙基亚胺酚配体的ⅣB族烯烃聚合催化剂以及制备双峰分布聚乙烯(英)

选择含有烯丙基亚胺酚为辅助配体，设计合成了5个ⅣB族钛锆金属络合物[{CH₂=CHCH₂N=CH-C₆H₃(3-R)O}₂MCl₂](4a：R=t-Bu，M=Zr；4b：R=t-Bu，M=Ti；4c：R=Ph，M=Zr；4d：R=Ph，M=Ti)和[{(CH₃)₂CHCH₂N=CH-C₆H₃(3-t-Bu)O}₂ZrCl₂] (5)，对它们进行了红外光谱、核磁共振及元素分析表征。并用X-射线单晶衍射法测定了化合物4a和4d的晶体结构。部分配合物在助催化剂MMAO的作用下对烯烃聚合显示了较好的催化活性，其中自固载催化剂4a生成了双峰分布的聚烯烃产品 (M_w/M_n=15.3～31.9)。     

取代茚基的茂金属Ti、Zr化合物的合成及其催化乙烯聚合活性

茂金属化合物;烯烃聚合;取代茚基的茂金属Ti、Zr化合物的合成及其催化乙烯聚合活性     

[O(S),O=P]型配体修饰的单氯单茂锆催化剂的高温乙烯聚合

以Ph3CB(C6F5)4/iBu3Al作为助催化体系,研究了单氯半茂型催化剂,ClCp′Zr[X-2-R1-4-R2-6-(Ph2P=O)C6H2]2(Cp′=C5H5,a:X=O,R1=Ph,R2=H;b:X=O,R1=F,R2=H;c:X=O,R1=tBu,R2=H;d:X=O,R1=R2=tBu;e:X=O,R1=SiMe3,R2=H;f:X=S,R1=SiMe3,R2=H;Cp′=C5Me5;g:X=O,R1=SiMe3,R2=H)的乙烯高温（50~125 ℃）聚合行为。 结果表明,催化剂a~d可在高温(50~100 ℃)下高效引发乙烯聚合,最佳反应温度为75 ℃。 适当增大R1取代基的位阻或引入吸电子取代基均有利于提高催化活性。 三甲基硅烷基取代的催化剂[WTHZ]e[WTBZ]耐高温性能较催化剂a~d大大提升,在100 ℃时,乙烯聚合活性可达5628 kg/(mol Zr·h)。 金属中心的配位原子及茂环上取代基团的改变对催化活性和聚合物的相对分子质量分布有一定的影响。     

Reaction of vinyl chloride with group 4 metal olefin polymerization catalysts

The reactions of three types of group 4 metal olefin polymerization catalysts, (C(5)R(5))(2)ZrX(2)/activator, (C(5)Me(5))TiX(3)/MAO (MAO = methylalumoxane), and (C(5)Me(4)SiMe(2)N(t)Bu)MX(2)/activator (M = Ti, Zr), with vinyl chloride (VC) and VC/propylene mixtures have been investigated. Two general pathways are observed: (i) radical polymerization of VC initiated by radicals derived from the catalyst and (ii) net 1,2 VC insertion into L(n)MR(+) species followed by beta-Cl elimination. rac-(EBI)ZrMe(mu-Me)B(C(6)F(5))(3) (EBI = 1,2-ethylenebis(indenyl)) reacts with 2 equiv of VC to yield oligopropylene, rac-(EBI)ZrCl(2), and B(C(6)F(5))(3). This reaction proceeds by net 1,2 VC insertion into rac-(EBI)ZrMe(+) followed by fast beta-Cl elimination to yield [rac-(EBI)ZrCl][MeB(C(6)F(5))(3)] and propylene. Methylation of rac-(EBI)ZrCl(+) by MeB(C(6)F(5))(3)(-) enables a second VC insertion/beta-Cl elimination to occur. The evolved propylene is oligomerized by rac-(EBI)ZrR(+) as it is formed. At high Al/Zr ratios, rac-(EBI)ZrMe(2)/MAO catalytically converts VC to oligopropylene by 1,2 VC insertion into rac-(EBI)ZrMe(+), beta-Cl elimination, and realkylation of rac-(EBI)ZrCl(+) by MAO; this process is stoichiometric in Al-Me groups. The evolved propylene is oligomerized by rac-(EBI)ZrR(+). Oligopropylene end group analysis shows that the predominant chain transfer mechanism is VC insertion/beta-Cl elimination/realkylation. In the presence of trace levels of O(2), rac-(EBI)ZrMe(2)/MAO polymerizes VC to poly(vinyl chloride) (PVC) by a radical mechanism initiated by radicals generated by autoxidation of Zr-R and/or Al-R species. CpTiX(3)/MAO (Cp = C(5)Me(5); X = OMe, Cl) initiates radical polymerization of VC in CH(2)Cl(2) solvent at low Al/Ti ratios under anaerobic conditions; in this case, the source of initiating radicals is unknown. Radical VC polymerization can be identified by the presence of terminal and internal allylic chloride units and other "radical defects" in the PVC which arise from the characteristic chemistry of PCH(2)CHCl(*) macroradicals. However, this test must be used with caution, since the defect units can be consumed by postpolymerization reactions with MAO. (C(5)Me(4)SiMe(2)N(t)Bu)MMe(2)/[Ph(3)C]][B(C(6)F(5))(4)] catalysts (M = Ti, Zr) react with VC by net 1,2 insertion/beta-Cl elimination, yielding [(C(5)Me(4)SiMe(2)N(t)Bu)MCl][B(C(6)F(5))(4)] species which can be trapped as (C(5)Me(4)SiMe(2)N(t)Bu)MCl(2) by addition of a chloride source. The reaction of rac-(EBI)ZrMe(2)/MAO or [(C(5)Me(4)SiMe(2)N(t)Bu)ZrMe][B(C(6)F(5))(4)] with propylene/VC mixtures yields polypropylene containing both allylic and vinylidene unsaturated chain ends rather than strictly vinylidene chain ends, as observed in propylene homopolymerization. These results show that the VC insertion of L(n)M(CH(2)CHMe)(n)R(+) species is also followed by beta-Cl elimination, which terminates chain growth and precludes propylene/VC copolymerization. Termination of chain growth by beta-Cl elimination is the most significant obstacle to metal-catalyzed insertion polymerization/copolymerization of VC.