陳竹亭臺灣大學：化學研究所林雅淇Lin, Ya-ChiYa-ChiLin2007-11-262018-07-102007-11-262018-07-102006http://ntur.lib.ntu.edu.tw//handle/246246/51793一系列胺基-吡啶雙牙配位基(L)及其中性與陽離子鈀金屬錯合物(Pd(L)MeCl; [Pd(L)Me(MeCN)]BF4)，成功地被合成出來。藉由X光單晶繞射與NMR鑑定，可知平面四邊形的鈀金屬錯合物包含兩種結構異構物，分別是順式和反式異構物。在中性鈀金屬錯合物中，順式異構物的比例從24% (CLH-1b)至90% (CLH-1f)，此比例與配位基的電子效應有關，然而取代基立體效應顯著者，會驅使反式異構物比例增加；但在陽離子鈀金屬錯合物中，除了LH-2a (45%)和LH-2c (20%)之外，電子效應的影響使反式異構物成為主要產物。X 光單晶繞射得知平面四邊形的鈀金屬錯合物的五員環配位平面因N1(Py)-Pd-N2夾角較小(78.85o-81.47o) 造成呈現輕微變形。此外中性與陽離子鈀金屬錯合物中鈀與甲基的距離分別為2.012 Å~2.087 Å與2.008 Å~2.032 Å，同時甲基均會造成對位的胺基或吡啶與鈀金屬的鍵長增長，顯示甲基的反式影響大於氯與乙腈配基。 胺基-吡啶雙牙配位基鈀金屬錯合物可以進行乙烯與降冰片烯的共聚合反應，活性約在7×103 至1.4×104 g(COC)/mol Pd h範圍。所產生之白色固體的共聚物產物(Cyclo olefin copolymer; COC)則依催化劑不同，其GPC呈現單峰或是雙峰分佈，但主要部分的分子量約為105等級，而降冰片烯於COC中的含量為43-65 mol%。從13C NMR 光譜分析，產生的COC主要屬於亂排的交錯序列(alternating sequence)，小部分(3.8%-25%)為連續降冰片烯所造成diads或triads。藉由Fineman-Ross動力學分析得到的r1×r2=0.01 (r1=0.09 and r2=0.11; r1=kEE/kEN, r2=kNN/kNE)，說明連續移動插入相同的單體機會只有9~11%，進一步證明此系統產生的大部分為交錯序列。一般而言，共聚合反應活性與降冰片烯在共聚物中的含量相關，降冰片烯含量高者，活性較低；在同樣的單體比例(XNB=56.20%)，胺基取代為芳香族的鈀金屬中心提供較大的空間使降冰片烯移動插入機會增加，達到60 mol%含量。在一系列變因探討中，改變單體濃度可有效調節共聚物中的降冰片烯含量(39~62 mol%)；反應溶劑則對於共聚物的分子量分佈與活性有明顯影響。 進一步使用電噴灑游離質譜法(ESI-MS)探討胺基-吡啶雙牙配位基鈀金屬錯合物催化乙烯與降冰片烯共聚合反應之反應機制，顯示陽離子鈀金屬錯合物經由乙腈解離活化，與降冰片烯在加壓乙烯前，先進行聚合反應。從乙烯寡聚合反應的實驗中，發現乙烯單體與催化劑配位易發生β-氫消除反應(β-hydrogen elimination)，佐證在13C NMR 光譜分析中COC鏈結尾為乙烯基的現象。在ESI-MS光譜中，亦可發現同時新產生的Pd-H物種同樣可以進行催化反應。 經由低溫1H NMR分析鈀金屬錯合物的順式與反式結構異構物對於單體的反應性，顯示順式異構物對於乙烯與降冰片烯均有較高的反應活性。NOESY光譜鑑定得知乙烯與降冰片烯移動插入後的錯合物屬反式異構物，主因係推測乙腈在吡啶對位，而立體障礙大的碳鏈選擇與吡啶同邊可避開胺基上較大的立體障礙，使其結構達至穩定。1. Introduction 1 1-1. Development of polymer and copolymer 1 1-2. Historical development of ethylene and norbornene copolymers 2 1-2.1 Contribution of Metallocene-type catalyst 3 1-2.2 Contribution of non-Metallocene type catalyst 5 1-2.3 Contribution of cationic catalyst 8 1-2.4 Well performance catalyst in alternating E-NB copolymerization 11 1-2.5 Mechanism of alternating ethylene/norbornene copolymers 11 1-3. Design of palladium complexes catalyst bearing amino-pyridine ligands 14 1-3.1 Background of palladium complexes bearing bidetate lignads 14 1-3.2 C1 and C2-symmetry bidentate ligands used in alternating copolymerizations 15 1-3.3 Design of the Amino-pyridine ligands 17 1-4. Goal and experimental design of this manuscript 19 2. Catalyst design: synthesis and characterization of palladium complexes with amino-pyridine ligands 21 2-1. Synthesis of amino-pyridine ligands 21 2-2. Synthesis of natural and cationic palladium complexes 24 2-3. Coordination chemistry of amino-pyridine ligands 26 2-3.1 Isomer definition of natural palladium complexes 26 2-3.2 Isomer definition of cationic palladium complexes 32 2-3.3 Ratio of cis/trans isomer of neutral and cationic palladium complexes 34 2-4. Variable-temperature NMR studies on the fluxional behavior 37 2-4.1 Dynamic properties of the palladium complex NLH-1d 37 2-4.2 Dynamic properties of the Pd(Ⅱ) complexes bearing LH-1e and LH-2e ligands 45 2-5. Solid state structure 49 2-4.1 Neutral palladium complexes 49 2-4.2 Cationic palladium complexes 57 3. Reactivity in ethylene/norbornene copolymerization and microstructure characterization of copolymers 61 3-1. Composition and microstructure in ethylene/norbornene copolymers 61 3.1-1 Stereoregular alternating E-NB copolymers 61 3.1-2 Mechanism studies of ethylene/norbornene copolymerization 62 3.1-3 Synthesis procedure of E-NB copolymers 67 3-2. Investigation of the microstructure of ethylene/norbornene copolymers 67 3.2-1 Molecular weight analysis from GPC 67 3.2-2 NMR studies 69 3.2-3 Norbornene content in copolymer and its thermal properties 78 3-3. Ethylene/norbornene copolymerization promoted by the neutral palladium complexes 82 3.3-1 Ligands modification vs. E/NB copolymerization activity 87 3-4. Reaction conditions on ethylene/norbornene copolymerization 91 3-4.1 Variation in ethylene pressure 91 3-4.2 Effect of norbornene concentration 92 3-4.3 Effect of catalyst concentration 99 3-4.4 Effect of reaction temperature on catalyst performance 101 3-4.5 Effect of reaction time 103 3-4.6 Effect of dilution during polymerization 106 3-4.7 Effect of solvent used in E/NB copolymerization 108 3-4.8 Effect of additive in ethylene/norbornene copolymerization 110 3-5. Modeling of ethylene/norbornene copolymerization 113 3-5.1 Determination of E/NB reactivity ratios for neutral palladium complex 113 3.5-2 How does bimodal weight distribution occur? 118 3-5.3 Electrospray ionization tandem mass spectrometries as a tool for catalyst screening 124 4. Fundamental studies on the reactivity of norbornene and ethylene on methylpalladium(Ⅱ) compound 132 4-1. Kinetic study of norbornene insertion 132 4-1.1 Norbornene insertion studies with complex NLH-1b 132 4-1.2 Norbornene insertion studies with complex CLH-1b 132 4-1.3 Norbornene insertion studies with complex CLH-2a 136 4-1.4 Norbornene insertion studies at low temperature 138 4-2. Kinetic study of ethylene toward cationic palladium complex 142 4-2.1 Ethylene insertion studies with complex CLH-1b 142 4-2.2 Ethylene insertion studies with complex CLH-2a 145 5. Conclusions 150 6. Experimental section 154 6-1. Ligand and palladium complexes synthesis 154 6-2. Variable-temperature NMR experiments 178 6-3. Ethylene and norbornene copolymerization procedure 178 References 180 Appendix 18695409832 bytesapplication/pdfen-US陽離子鈀金屬錯合物共聚合反應copolymerizationcationic palladium complexamino-pyridine ligandthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51793/1/ntu-95-D91223014-1.pdf