本論文利用實驗室自行架設的飛秒瞬態吸收光譜儀(transient absorption, TA)及一套自動化數據擷取電腦程式，研究電子給體-受體(electron donor-acceptor, EDA)錯合物中的分子間電荷轉移動力學行為。本論文分為兩個主題：第一個是觀察直接激發烯烴類1-己烯/四氰基乙烯 (1-hexene/tetracyanoethylene, Hex/TCNE)錯合物的電荷轉移(charge transfer, CT)態後的電荷轉移動力學；第二個是觀察直接激發芳香族苯甲腈/四氰基乙烯(benzonitrile/tetracyanoethylene, PhCN/TCNE)錯合物的CT態後的電荷轉移動力學。在第一個主題中，我們觀察到四氰基乙烯陰離子(TCNE)的瞬態吸收光譜及其時間變化之行為，並與本實驗室前人研究之BZ/TCNE錯合物CT態電荷轉移動力學進行比較。我們觀察到激發錯合物CT態後，錯合物會先進行溶劑緩解(約0.5 ps)，並接著進行電荷再結合(charge recombination, CR)的過程(約3 ps)。比較Hex/TCNE以及BZ/TCNE的瞬態吸收光譜我們更確定實驗室前人對於苯二聚體陽離子((BZ)2+)的指認，並且推測在Hex/TCNE溶液中並沒有(Hex)2+的形成。在第二個主題中，我們觀察到TCNE、苯甲腈陽離子(PhCN+)以及苯甲腈二聚體陽離子((PhCN)2+)的瞬態吸收光譜及其時間變化之行為。我們發現錯合物CT態會先進行較快的溶劑緩解與振動緩解過程，接著為較慢的CR反應，且其CR速率隨溶劑中PhCN比例改變有顯著的變化。在與BZ/TCNE的比較中，我們驚訝地發現在PhCN/TCNE系統中D+A型錯合物的CR速率比(DD)+A型錯合物的CR速率快，與BZ/TCNE系統中的趨勢相反，其可能原因為系統的反應自由能(-〖ΔG〗^0)與電子耦合強度(HAB)在不同系統中的影響程度不同。我們也發現在相似溶劑條件下，不論是D+A型或(DD)+A型錯合物的CR速率在PhCN/TCNE系統中都較慢，其可能原因為系統的-〖ΔG〗^0較大並且HAB較弱導致CR速率較慢。

We study the charge-transfer (CT) dynamics of the electron donor-acceptor (EDA) complexes with broadband femtosecond transient absorption (TA) spectroscopy. The thesis is mainly divided into two topics. In the first topic, we directly excite the CT state of 1-hexene/tetracyanoethylene (Hex/TCNE) complexes to observe their relaxation dynamics and compare the results with the previously-studied BZ/TCNE complexes in our laboratory. We observed TA spectra of TCNE anion (TCNE) and their temporal behaviors. By analyzing their time-dependent behaviors, we found that after exciting the CT state of Hex/TCNE complexes, the excited state complexes undergo rapid solvation relaxation, followed by a slower charge recombination (CR) reaction. Comparing with the results of previously-studied BZ/TCNE system, we did not observe the formation of dimer cation in Hex/TCNE system, but we found that the CR rate of Hex/TCNE complex is faster than those of BZ/TCNE complexes by one to two orders of magnitude due to the enhanced electronic coupling strength (HAB). In the second topic, we excite the CT state of benzonitrile/tetracyanoethylene (PhCN/TCNE) complexes. We observe TA spectra of TCNE, benzonitrile cation (PhCN)+ and benzonitrile dimer cation ((PhCN)2+). By analyzing their time-dependent behaviors, we found that after exciting the CT state of PhCN/TCNE complexes, the excited state complexes undergo rapid solvation and vibrational relaxation, followed by a slower CR reaction, which is strongly dependent on the donor concentrations in solutions. Comparing with the CR process of previously-studied BZ/TCNE complexes, we noticed a different trend in the CR rate of the PhCN/TCNE complexes as the donor concentration increases. Surprisingly, in contrast to BZ/TCNE complexes, the CR rate of the D+Atype is faster than (DD)+Atype in PhCN/TCNE complexes probably due to the different in HAB and reaction free enengy (-〖ΔG〗^0) in the two systems. On top of that, the CR rates are slower in PhCN/TCNE complexes than in BZ/TCNE complexes in similar solvent environments for both D+Aor (DD)+Atypes. The possible reason is related to a greater -〖ΔG〗^0 and a weaker HAB in PhCN/TCNE complexes, leading to their slower CR rates.

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