劉國平臺灣大學：化學研究所呂育儒Lu, Yu-JuYu-JuLu2007-11-262018-07-102007-11-262018-07-102005http://ntur.lib.ntu.edu.tw//handle/246246/51926本論文主要分為三部分。第一部分利用交叉分子束技術來研究O(1D)與N2O的反應。此反應有兩個放熱產物通道﹕NO + NO和N2 + O2。前者生成兩種NO分子，一種是原本存在N2O之中的“舊”NO，另一種是在反應中生成的“新”NO。使用同位素標記的18O(1D)分子束以及質譜檢測方法，我們可以分辨“舊”和“新”兩種的NO分子。在碰撞能為7.8 kcal/mol條件下，各別測量產物30NO、32NO和34O2的飛行時間譜以及角分佈。進一步可獲得兩反應通道的產物平移動能分佈。由能量守恆，產物的內能也可被決定。並且，我們搜尋同位素交換反應產生與否，結果顯示它的產率低於我們儀器的偵測極限，即使有反應，其產率也極小。 第二部分則是以相同技術研究F2與CH3SCH3 (Dimethyl Sulfide, DMS) 的反應。目前已經偵測到m/z = 80的反應訊號，而且角分佈明顯地為前向散射。令人不能預期的是兩個closed shell的分子，其速率常數可能像自由基反應一樣快。其中DMS為低游離能，F2為高電子親合力的分子，推測其反應機制經由一個charge-transfer complex。 第三部分內容主要在描述儀器參數的校正工作。做一系列分子的光解，校正分析數據所需輸入的儀器參數。This thesis is divided into three sections. The first section is that the reaction of O(1D) with nitrous oxide, N2O, has been investigated using the crossed molecular beam technique. There are two exothermic product channels：NO + NO and N2 + O2. The former produces two kinds of NO molecules, an “old” NO which already exists in the N2O molecule and a “new” NO which is newly formed in the reaction. Using the isotope labeled 18O(1D) with mass spectrometric detection, we could distinguish the “old” and “new” NO molecules. The product time-of-flight spectra and angular distributions have been measured for 30NO, 32NO, and 34O2 at a collisional energy of 7.8 kcal/mol. The translational energy distributions of the two product channels could be obtained. From the reaction energetics, the product total internal energy could be determined for both channels. We also searched for the isotope exchange reaction channel, 18O(1D) + 44N2O → 16O(1D,3P) + 46N2O, but its yield is below our detection limit. The second section is about the reaction of F2 with CH3SCH3 (Dimethyl Sulfide, DMS) by using the same technique. The signals at m/z = 80 have been detected. The angular distribution is significantly forward respect to DMS. It is a surprise that the rate constant of two closed shell molecules might be as fast as a radical reaction. The reaction mechanism is supposed to form a charge-transfer complex because of low ionization potential of DMS and high electron affinity of F2. The final section is about the calibrations of machine parameters. The machine parameters are calibrated by photodissociation of a series of molecules, which provide the basis to analyze our data.Abstract 摘要 謝誌 目錄 圖表目錄 第一章、 O(1D) 與N2O之交叉分子束研究......................1 一、前言..................................................1 二、實驗........................................................9 ◆0° source...................................................10 ◆90° source...................................................11 ◆Even-Lavie valve和General valve之間的比較..............11 ◆測量分子束的速度.......................................12 ◆延遲時間最佳化.........................................13 ◆雷射處理方式、能量及trigger offset測量.................14 ◆實驗設置...............................................14 1. source腔體.......................................................15 2. 主腔體..........................................15 3. 偵測器腔體......................................16 ◆實驗室座標 (LAB frame) 轉換到質心座標 (C.M. frame).....18 ◆定義中性產物飛行時間...................................18 三、實驗結果.............................................18 1. 32NO + 30NO.....................................19 2. N2 + 34O2.......................................23 3. 同位素交換......................................25 4. Branching ratio.................................26 四、討論.................................................27 五、總結.................................................34 六、參考文獻.......................................................35 第二章、F2與CH3SCH3之交叉分子束的初步研究................37 一、前言.................................................37 二、實驗.................................................38 ⣶98; 0° source.............................................39 ⣶98; 90° source............................................39 三、初步的實驗結果.......................................40 四、總結.................................................42 五、未來工作.............................................42 六、參考文獻.............................................43 附錄、儀器參數校正.......................................44 ◆參考文獻...............................................461578488 bytesapplication/pdfen-US交叉分子束牛頓圖crossed molecular beamnewton diagramthesishttp://ntur.lib.ntu.edu.tw/bitstream/246246/51926/1/ntu-94-R92223061-1.pdf