成功大學博碩士論文系統

簡易檢索 / 詳目顯示

回結果列表

研究生：	蘇煒林 Su, Wei-Lin
論文名稱：	以密度泛函理論研究Cyclometalated Phenylpyridine銥(III)錯合物分子軌域 Theoretical Study of Molecular Orbital of Cyclometalated Phenylpyridine Ir(III) Complexes Using Density Functional Theory
指導教授：	王小萍 Wang, Shao-Pin
學位類別：	碩士 Master
系所名稱：	理學院 - 化學系 Department of Chemistry
論文出版年：	2006
畢業學年度：	94
語文別：	英文
論文頁數：	27
中文關鍵詞：	有機發光二極體、函時密度泛函理論、天然鍵性軌域
外文關鍵詞：	LCBO-MO, NBO, OLED, TD-DFT
相關次數：	點閱：109 下載：1
分享至:	分享至facebook 分享至twitter

查詢本校圖書館目錄查詢臺灣博碩士論文知識加值系統勘誤回報

三個銥(III)錯合物Ir(ppy)2(CN)2- (1)、Ir(ppy)2(NCS)2- (2) 和Ir(ppy)2(NCO)2- (3)的光物理性質在文獻中已被發現和探討。經由我們理論計算(TD-DFT) 結合了溶劑效應(CPCM)所得的最低三重激發態與能量，和文獻報導的放光波長比較可得到令人信服的結果。藉由分析三個錯合物Optical Orbitals (HOMO 和 LUMO)的組成，我們可以瞭解造成實驗上放光行為的差異(藍、綠、黃)是源自於配位子的p-donating或p-accepting特性所造成的HOMO能階位移。我們修改了Roald Hoffmann 的分子軌域作用圖，來表示配位子中硫或氧的孤對電子與NC p-p* 體系的相互作用。而這些分子軌域，則是基於天然鍵性軌域方法所獲得。

The photophysical properties of a series of cyclometalated Ir(III) complexes Ir(ppy)2(CN)2- (1), Ir(ppy)2(NCS)2- (2), and Ir(ppy)2(NCO)2- (3) (where ppy = 2-phenyl pyridine, CN = cyanide, NCS = isothiocyanate, and NCO = isocyanate) have been reported. It is concluded that time-dependent density functional theory (TD-DFT) calculations supply theoretical interpretation of the triplet excited states and the nature of photophysical behaviors reported in literature. Combined with conductive polarizable continuum model (CPCM) the calculations are valid in examining the solvent effect on excitation energies. Analysis of highest occupied molecular orbital (HOMO) and lowest unoccupied orbital (LUMO) obtained by B3LYP functional reveals effects of p-donating and/or p-accepting properties of three pseudohalogens on optical orbitals in complexes 1, 2, and 3. The origin of HOMO tuning up, results in the blue, green and yellow photoluminescence observed in experiments, can be interpreted by interaction between the lone pairs perturbed p-p*(NC) system with metal dp orbitals. We have modified the Hoffman’s orbital interaction diagram to demonstrate effects of sulfur or oxygen atoms on the energy of p(NC). The degree of HOMO tuning-up is parallel to the lone-pair contribution to the perturbed p (NC) analyzed by the natural bonding orbital (NBO) method.

摘要..........................................................................Ⅰ
Abstract......................................................................Ⅱ
Context.......................................................................Ⅲ
List of Schemes..............................................................IⅤ
List of Tables...............................................................IⅤ
List of Figures..............................................................IⅤ
1.  Introduction...............................................................1
2.  Theoretical Methods........................................................3
2.1 Natural Bonding Orbital....................................................3
2.2 Second Order Perturbation Theory...........................................4
2.3 Linear Combination of Bond Orbital-Molecular Orbitals (LCBO-MO)............5
2.4 Spin Densities.............................................................5
2.5 Time-Dependent Density Functional Theory...................................6
3.  Computational Details......................................................8
4.  Results and Discussions....................................................9
4.1 Ground State Structures....................................................9
4.2 Molecular Orbital Energies and Composition.................................9
4.3 s-donating and p-accepting Properties of Pseudohalogens...................11
4.4 LCBO-MO Analyses..........................................................12
4.5 Ionization Potentials and Spin Densities..................................14
4.6 TD-DFT Results............................................................15
5.  Conclusion................................................................17
 

List of Schemes
Scheme 1 Orbital Interaction in Complexes.....................................18
Scheme 2 Orbital Interactions in Pseudohalogens...............................19

List of Tables
Table 1 Selected ground state geometry parameters.............................20
Table 2 Frontier Orbitals of these Three Complexes............................20
Table 3 LCAO-MO of HOMOs in the Three Complexes...............................21
Table 4 s-donating and p-accepting Capabilities by Donor-Acceptor Interaction.21
Table 5 LCBO-MO of HOMOs by Pseudohalogens in the Three Complexes.............21
Table 6 Ionization Potentials and Spin Densities for the Three Complexes......22
Table 7 Triplet Excited States from TD-DFT/CPCM Calculation...................22

List of Figures
Figure 1a  Molecular Structure of [Ir(ppy)2(CN)2]-............................23
Figure 1b  Molecular Structure of [Ir(ppy)2(NCS)2]-...........................23
Figure 1c  Molecular Structure of [Ir(ppy)2(NCO)2]-...........................23
Figure 2   Orbital Energy and Assignment of Complexes Frontier Orbitals.......24
Figure 3   Contour Plots of Selected MOs......................................25
Figure 3a  HOMO of [Ir(ppy)2(CN)2]-...........................................25
Figure 3b  HOMO of [Ir(ppy)2(NCS)2]-..........................................25
Figure 3c  HOMO of [Ir(ppy)2(NCO)2]-..........................................25
Figure 3d  LUMO of [Ir(ppy)2(CN)2]-...........................................25
Figure 3e  LUMO of [Ir(ppy)2(NCS)2]-..........................................25
Figure 3f  LUMO of [Ir(ppy)2(NCO)2]-..........................................25

Reference.....................................................................26
                                    

[1] Baldo, M. A.; O’Brien, D. F.; You, Y.; Shoustikov, A.; Sibley, S.;hompson,
M. E.; Forrest, S. R. Nature 1998, 395, 151.
[2] Hung, L. S.; Chen, C. H. Mat. Sci. Eng. R. 2002, 39, 143.
[3] Tokito, S.; Lijima, T.; Tsuzuki, T.; Sato, F. Appl. Phys. Lett. 2003, 83,
2459.
[4] King, K. A.; Spellane, P. J.; Watts, R. J. J. Am. Chem. Soc. 1985, 107,
1431.
[5] Lamansky, S. Djurovich, P.; Murphy, D.; Abdel-Razaq, F.; Kong, R.; Tsyba,
I.; Bortz, M.; Mui, B.; Bau, R.; Thompson, M. E. Inorg. Chem. 2001, 40,
1704.
[6] Huang, Y. T.; Chuang, T. H.; Shu, Y. L.; Kuo, Y. C.; Wu, P. L.; Yang, C.
H.; Sun, I. W. Organometallics 2005, 24, 6230.
[7] Stratmann, R. E.; Scuseria, G. E.; Frisch, M. J. J. Chem. Phys. 1998, 109,
8218.
[8] Bauernschmitt, R.; Ahlrichs, R. Chem. Phys. Lett. 1996, 256, 454.
[9] Casida, M. E.; Jamorski, C.; Casida, K. C.; Salahub, D. R. J. Chem. Phys.
1998, 108, 4439.
[10] Foster, J. P.; Weinhold, F. J. Am. Chem. Soc. 1980, 102, 7211.
[11] Reed, A. E.; Weinstock, R. B. Weinhold, F. J. Chem. Phys. 1985, 83, 735.
[12] Reed, A. E.; Curtiss, L. A.; Weinhold, F. Chem. Rev. 1988, 88, 899.
[13] Nazeeruddin, M. K.; Humphry-Baker, R.; Berner, D.; Rivier, S.; Zuppiroli,
L.; Graetze, M. J. Am. Chem. Soc. 2003, 125, 8790.
[14] Brunck, T. K.; Weinhold, F., Linear-Combination-of Bond-Orbitals Approach
to SCF-MO Theory, Univerisity of Wisconsin Theoretical Chemistry Institute
Report WIS-TCI-560 (unpublished)
[15] Brunck, T. K.; Weinhold, F. J. Am. Chem. Soc. 1979, 101, 1700.
[16] Szabo, A.; Ostlund, N. S., Modern Quantum Chemistry; McGraw-Hill
Publishing Company: New York, 1982.
[17] Ernzerhof, M.; Scuseria, G.. E. Theor. Chem. Acc. 2000, 103, 259.
[18] Geerlings, P.; De Proft, F.; Langenaeker, W. Chem. Rev. 2003, 103, 1793.
[19] Becke, A. D. J. Chem. Phys. 1993, 98, 5648.
[20] Lee, C.; Yang, W.; Parr, R. Phys. Rev. B 1988, 37, 785
[21] Frisch, M. J. et al., Gaussian 98, Revision A.11, Gaussian, Inc.,
Pittsburgh, PA, 2001.
[22] Ditchfield, R.; Hehre, W. J.; Pople, J. A. J. Chem. Phys. 1971, 54, 724.
[23] Hay, P. J.; Wadt, W. R. J. Chem. Phys. 1985, 82, 299.
[24] Glendening, E. D.; Badenhoop, J. K.; Reed, A. E.; Carpenter, J. E.;
Bohmann, J. A.; Morales, C. M.; Weinhold, F. (Theoretical Chemistry
Institute, University of Wisconsin, Madison, WI, 2001);
http://www.chem.wisc.edu/~nbo5.
[25] Barone, V.; Cossi, M.; Tomasi, J. J. Comp. Chem. 1998, 19, 404.
[26] Barone, V.; Cossi, M. J. Phys. Chem. A 1998, 102, 1995.
[27] Villegas, J. M.; Stoyanov, S. R.; Wei, H.; Lockyear, L. L.; Reibenspies,
J. H.; Rillema, D. P. Inorg. Chem. 2004, 43, 6583.
[28] Villegas, J. M.; Stoyanov, S. R.; Reibenspies, J. H.; Rillema, D. P.
Organometallics 2005, 24, 395.
[29] Hay, P. J. J. Phys. Chem. A 2002, 106, 1634.
[30] Banerjea, D., Coordination Chemistry; Tata McGraw-Hill Publishing Company
Limited: New York, 1993.
[31] DeKock, R. L.; Gray, H. B., Chemical Structure and Bonding, 2nd ed.;
University Science Books: United States of America, 1989.
[32] Cotton, F. A., Chemical Applications of Group Theory, 3rd ed.; John Wiley
& Sons,Inc.: United States of America, 1990.
[33] Harris, D. C.; Bertolucci, M. D., Symmetry and Spectroscopy; Dover
Publications, Inc.: New York. 1978.
[34] Hoffmann, R. Acc. Chem. Res. 1971, 4, 1.

校內：2007-06-08公開
校外：2009-06-08公開

簡易檢索 / 詳目顯示

相關論文