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題 名 | 使用金屬茂/有機鋰觸媒系統來氫化SBS嵌段共聚物=Metallocene/Organolithium Catalyst Systems for the Hydrogenation of SBS Copolymers |
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作 者 | 蔣見超; 楊文賢; | 書刊名 | 化學 |
卷 期 | 57:1 1999.03[民88.03] |
頁 次 | 頁81-88 |
專 輯 | 聚合觸媒 |
分類號 | 468.8 |
關鍵詞 | 氫化; 金屬茂觸媒; 有機鋰; 正丁基鋰; Hydrogenation; Metallocene; Bis η[fec3]-cyclopentadienyl cobalt; Bis η[fec3]-cyclopentadienyl nickel; Bis η[fec3]-cyclopentadienyl titanium dichloride; n-butyllithium; Styrene; Butadiene; Block copolymer; |
語 文 | 中文(Chinese) |
中文摘要 | 當不同的金屬茂觸媒,包括bis(η��-cyclopentadienyl)cobalt、bis(η�� -cyclopenadienyl)nickel 和 bis( η�� -Cyclopentadieny1) titanium dichloride, 配 合上不同的還原劑, 包括正丁基鋰、苯基鋰、或三乙基鋰的時候,他們對 SBS 共聚合物的 氫化飽合反應有不同的催化效率。 其中, 以 bis( η�� -cyclopen- tadienyl)cobalt (Cp �浚O) 結合正丁基鋰 (n-BuLi) 所構成的觸媒系統被發現具有最良好之催化活性。 氫 氣的壓力與 Cp �� CO/ 正丁基鋰的比例皆會造成影響。 實驗數據顯示,此反應存在著一個 最適的氫氣壓力值以及最適的金屬茂 / 還原劑比例。 從此觸媒系統之紫外線光譜獲得的數 據指出,原來配位在 Cp �� Co 的 Cp 被丁基取代形成主要的觸媒物種 CpCoBu。 此氫化反 應的動力機制乃藉由使用 FTIR 光譜監看此共聚物中 polybutadiene 部份的雙鍵飽和程度 而得到。 |
英文摘要 | Ab initio calculations were performed to investigate the structures, energetics and vibrations of MH �� (H �� O) �a (M=NH ��, H �� O and (Ch �� )O �� ) cluster ions at n=0-5. For MH �� and MH �� -H �� O, geometries of the ions are optimized at MP2, CCD, QCISD and B3LYP levels using the various basis set: 6-31G*, 6- 31G**, 6-31+G*, 6-31++G**, 6-311+G** and 6-311++G**. Comparing the results of these calcullations suggests that MP2 and B3LYP methods with the 6-31+G* basis set are well suitable for characterizing larger MH �� (H �� O) �a clusters of n=2-5. From geometry optimizations and vibrational configurations, the two methods correspondingly predict the presence of a number of stable isomers for NH ���� (H �� 0). Particularly at n=5, a structure, comprising of a four-member ring with the second shell H �� O acting as a double proton acceptor, is predicted to be the lowest in energy. This prediction is in good accord with the observed vibrational predissociation spectra of NH �� (H �� O) �� synthesized in a supersonic beam [Wang et al., J. Am. Chem. Soc. 1998, 102, 8777], where a characteristic absorptions at ∼ 3550 cm �笐� is identified for the bonded-OH stretching of the four-membered ring. In this study, in addition to energetics, how hydrogen bonding nonadditivity influences the geometries and vibrations of these clusters in analyzed. |
本系統中英文摘要資訊取自各篇刊載內容。