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研究生:林聖家
研究生(外文):Sheng-Jia Lin
論文名稱:以電腦模擬研究香蕉型液晶元的分子交互作用力
論文名稱(外文):Computer simulations of the self assembly of banana-shaped mesogens
指導教授:賴重光, 蔡惠旭
學位類別:碩士
校院名稱:國立中央大學
系所名稱:化學研究所
學門:自然科學學門
學類:化學學類
論文種類:學術論文
論文出版年:2007
畢業學年度:95
語文別:中文
論文頁數:114
中文關鍵詞:B6液晶相量子化學計算全原子分子動態模擬香蕉形液晶分子
外文關鍵詞:banana-shaped liquid crystal mesogendensity functional theory calculationsmolecular dynamics simulations
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本論文利用全原子分子動態模擬和量子化學計算來研究香蕉形液晶的
結構、交互作用力及其動態行為。研究的香蕉形液晶分子(圖1.16)具有B6
液晶相,不同於一般常見的香蕉形液晶結構,中間連接基為剛硬的核心,
此一分子中間連接基為柔軟的飽和碳鏈連接兩邊硬核結構。
研究結果顯示,Schiff’s base 和苯環上的OH 基形成了分子內氫鍵,這
個氫鍵增強了Schiff’s base 和苯環的π-電子共振,使得這個分子的硬核較原
本預期的苯環來得大;此外,由於連接烷氧基的碳-氧鍵結具有部分雙鍵的
特性,限制了烷氧基連接端的構形,使得硬核的部分擴大到烷氧基的連接
端。
模擬結果顯示,多分子系統中分子的彎曲角度約120o 和單晶的結果
(128o)類似,屬於典型的香蕉形彎曲角度(110o ~140o)。由於分子內的的π-
π堆疊穩定能量,使得單分子系統的彎曲角度(~40o)較小,傾向形成髮夾型
(“hairpin”-like)的構形。單分子和多分子截然不同的彎曲角度顯示分子間交
互作用力不僅影響分子間的堆疊,也對香蕉形構形的形成,扮演著重要的
角色。此外,我們也觀察到分子間存在著重要的π-π 堆疊及分子間的氫鍵網
絡,顯示分子間排列的情況主要由這兩個作用力決定。
長時間的分子動態模擬顯示,烷氧基長碳鏈和硬核的夾角為一動態平
衡,分佈主要集中在0o 左右,擺幅大約 ±30o 左右。研究也顯示烷氧基長碳
鏈一方面可以增加硬段的大小; 另外一方面,它柔軟度也較飽和長碳鏈來得
大。
In this study, long time-scale all-atom molecular dynamics simulations and density functional
theory calculations were performed to study the structures, interactions and dynamics of a
banana-shaped liquid crystal mesogen. This molecule (see figure 1.16 for details) owns a
flexible alkyl linkage connecting to two rigid cores which is differential from the common
rigid one.
The results show that the intra-molecular hydrogen bond between the Schiff’s base and
benzene’s OH group enhances the π-e resonance between them and integrates these two
moieties into one rigid core. In addition, the characteristics of carbon-oxygen partially double
bond between the pendent chain and benzene limits its conformational space. Thus, the rigid
core extends from the moiety of benzene to the Schiff’s base and to the O-CH2 group of the
alkoxy chain.
The bending angle from the molecular dynamics simulations of the bulk system is ~120o, in
the reasonable range of 110o-140o for banana-shaped mesogens. Moreover, this calculated
bending angle is in good agreement with the observed 128o from the single crystal data.
Arising from the stabilizing energy of intra-molecular π-π stacking, the isolated molecule
prefers to form the hairpin-like conformation with a small bending angle of ~40o. The bending
angle of the isolated molecule is pretty different from the one of bulk system indicating that
the inter-molecular interactions can not only affect the organizations between molecules, but
also their bending angles. Additionally, the networks of inter-molecular hydrogen bonds and
inter-molecular π-π stacking were also observed from the 200 ns long time-scale molecular
dynamics simulations.
The angles between the alkoxy chain and rigid core are dynamical in liquid crystal phase
where the chains have the highest population to align with the same plane of the rigid core.
However, they fluctuate within a magnitude of ±30o up and down of the rigid core plane.
More interesting, our simulations show the alkoxy chain enlarges the rigid core, on the other
hand, it is more flexible than the saturated alkyl chain.
中文摘要 III
Abstract IV
目錄 VI
圖目錄 VIII
表目錄 XII
第一章、緒論 1
1-1 前言 1
1-2 液晶的起源及簡介 1
1-3 液晶相形成之要件 2
1-4 液晶的分類 3
1-6 香蕉型分子構型 12
1-7 分子基本物性 15
1-8 研究動機 17
第二章、分子動態模擬 18
2-1 分子動態模擬的簡介及應用 18
2-2 分子動態模擬原理 18
2-2-1 分子力場 18
2-2-2 基本動力原理 23
2-2-3 基礎模擬系統 25
2-2-4 週期性邊界條件 25
2-3 力場參數設定 27
2-4 分子動態模擬的系統及條件 38
第三章、結果與討論 39
3-1 分子結構 41
3-1-1 硬段核心 41
3-1-2 彎曲角度 45
3-1-3 分子內硬核的π-π堆疊 53
3-2 分子間作用力 56
3-2-1 分子間硬核π-π堆疊 56
3-2-2 分子間氫鍵 57
3-3 側鏈基構形及動態 62
3-3-1 側鏈基個別雙面角構形的分佈 62
3-3-2 側鏈基整體雙面角構型的分佈 69
3-3-3 側鏈基長度對仰角的分佈 71
3-3-4 側鏈基的動態行為 74
第四章、結論 76
參考文獻 78
附錄 80
(1)Pauluth, D.; Tarumi, K. J. Mater. Chem. 2004, 14, 1219.
(2)Paraschiv, I.; Giesbers, M.; vanLagen, B.; Grozema, F. C; Siebbeles, L. D. A.; Marcelis, A. T. M.; Zuilhof, H.; Sudholter, E. J. R. Chem. Mater. 2006, 18, 968.
(3)Yelamaggad, C. V.; Mathews, M.; Nagamani, S. A.; Prasad, S. K.; Findeisen, S.; Weissflog, W. J. Mater. Chem. 2007, 17, 284.
(4)T. Niori; T. Sekine; J. Watanabe; T. Furukawa; Takezoe, H. J. Mater. Chem. 1996, 6, 1231.
(5)Gerhard Pelzl, S. D. W. W. Advanced Materials 1999, 11, 707.
(6)Reddy, R. A.; Sadashiva, B. K.; Raghunathan, V. A. Chem. Mater. 2004, 16, 4050.
(7)Reddy, R. A.; Sadashiva, B. K. J. Mater. Chem. 2004, 14, 1936.
(8)Rouillon, J. C.; Marcerou, J. P.; Laguerre, M.; Nguyen, H. T.; Achard, M. F. J. Mater. Chem. 2001, 11, 2946.
(9)Kresse, H.; Schmalfuss, H.; Weissflog, W. Liquid Crystals 2001, 28, 799
(10)Fodor-Csorba, K.; Matyus, E. Liquid Crystals 2003, 30, 445
(11)Achten, R.; Koudijs, A.; Karczmarzyk, Z.; Marcelis, A. T. M. Liquid Crystals 2004, 31, 215
(12)Pelzl, G.; Schroder, M. W.; Dunemann, U.; Diele, S.; Weissflog, W.; Jones, C.; Coleman, D.; Clark, N. A.; Stannarius, R.; Li, J.; Das, B.; Grande, S. J. Mater. Chem. 2004, 14, 2492.
(13)D.S.Shankar Rao; Geetha G. Nair; S. K Prasad; Yelamaggad, C. V. Liquid Crystals 2001, 28, 1239
(14)Weissflog, W.; Nadasi, H.; Dunemann, U.; Pelzl, G.; Diele, S.; Eremin, A.; Kresse, H. J. Mater. Chem. 2001, 11, 2748.
(15)Allen, M. P.; Tildesley, D. J. Computer Simulation of Liquids; Clarendon Press: Oxford, 1987.
(16)Karplus, M. Biopolymers 2003, 68, 350.
(17)Cacelli, I.; DeGaetani, L.; Prampolini, G.; Tani, A. J. Phys. Chem. B 2007, 111, 2130.
(18)Denis, A.; Valentina, M.; Kurt, K. The Journal of Chemical Physics 2006, 125, 124902.
(19)Andrienko, D.; Marcon, V.; Kremer, K. The Journal of Chemical Physics 2006, 125, 124902.
(20)Wilson, M. R. International Reviews in Physical Chemistry 2005, 24, 421
(21)Memmer, R. Liquid Crystals 2002, 29, 483.
(22)Tsai, H.-H.; Zanuy, D.; Haspel, N.; Gunasekaran, K.; Ma, B.; Tsai, C. J.; Nussinov, R. Biophysical Journal 2004, 87, 146.
(23)Tsai, H.-H.; Tsai, C.-J.; Ma, B.; Nussinov, R. Protein Sci 2004, 13, 2753.
(24)Tsai, H.-H.; Reches, M.; Tsai, C.-J.; Gunasekaran, K.; Gazit, E.; Nussinov, R. Proceedings of the National Academy of Sciences of the United States of America 2005, 102, 8174.
(25)Cheung, D. L.; Clark, S. J.; Wilson, M. R. Physical Review E 2002, 65, 051709.
(26)Cacelli, I.; Prampolini, G.; Tani, A. J. Phys. Chem. B 2005, 109, 3531.
(27)James C. Phillips, R. B., Wei Wang, James Gumbart, Emad Tajkhorshid, Elizabeth Villa, Christophe Chipot, Robert D. Skeel,. Journal of Computational Chemistry 2005, 26, 1781.
(28)Kale, L.; Skeel, R.; Bhandarkar, M.; Brunner, R.; Gursoy, A.; Krawetz, N.; Phillips, J.; Shinozaki, A.; Varadarajan, K.; Schulten, K. Journal of Computational Physics 1999, 151, 283.
(29)MacKerell, A. D.; Bashford, D.; Bellott, M.; Dunbrack, R. L.; Evanseck, J. D.; Field, M. J.; Fischer, S.; Gao, J.; Guo, H.; Ha, S.; Joseph-McCarthy, D.; Kuchnir, L.; Kuczera, K.; Lau, F. T. K.; Mattos, C.; Michnick, S.; Ngo, T.; Nguyen, D. T.; Prodhom, B.; Reiher, W. E.; Roux, B.; Schlenkrich, M.; Smith, J. C.; Stote, R.; Straub, J.; Watanabe, M.; Wiorkiewicz-Kuczera, J.; Yin, D. Journal of Physical Chemistry B 1998, 102, 3586.
(30)Quigley, D.; Probert, M. I. J. Journal of Chemical Physics 2004, 120, 11432.
(31)Feller, S. E.; Zhang, Y.; Pastor, R. W.; Brooks, B. R. Journal of Chemical Physics 1995, 103, 4613.
(32)Andersen, H. C. Journal of Computational Physics 1983, 52, 24.
(33)Essmann, U.; Perera, L.; Berkowitz, M. L.; Darden, T.; Lee, H.; Pedersen, L. G. Journal of Chemical Physics 1995, 103, 8577.
(34)Yelamaggad, C. V.; Shashikala, I.; Shankar Rao, D. S.; Krishna Prasad, S. Liquid Crystals 2004, 31, 1027.
(35)Reddy, R. A.; Tschierske, C. J. Mater. Chem. 2006, 16, 907.
(36)Janiak, C. Journal of the Chemical Society, Dalton Transactions 2000, 3885.
(37)Sinnokrot, M. O.; Sherrill, C. D. J. Phys. Chem. A 2006, 110, 10656.
(38)Eswar, N.; Ramakrishnan, C. Protein Engineering 2000, 13, 227.
(39)Cheng, G. Q.; Dong, R. Y. Journal of Chemical Physics 1988, 89, 3308.
(40)Cinacchi, G.; Colle, R.; Tani, A. J. Phys. Chem. B 2004, 108, 7969.
(41)Cinacchi, G.; Prampolini, G. J. Phys. Chem. A 2003, 107, 5228.
(42)Rutar, V.; Blinc, R.; Vilfan, M.; Zann, A.; Dubois, J. C. The Journal of Physical Chemistry 1982, 43, 761.
(43)Goldfarb, D.; Luz, Z.; Zimmermann, H. The Journal of Chemical Physics 1983, 78, 7065.
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