氯化亞甲基分子(monochloromethylene, HCCl)為有機、大氣及材料化學中相當重要的反應中間物。但是先前的文獻受限於偵測器觀測範圍及光譜的訊雜比不良，所以對於其基態振動資訊的瞭解仍不夠完整，而且無法由實驗結果精確地得知單重態(singlet state)與三重態(triplet state)之能階差(energy gap, ΔEST)值。 本論文利用超音速自由噴射分子束及高壓直流放電裝置搭配增強式電荷耦合偵測器(ICCD)，成功取得HCCl及DCCl在可見光區之新螢光分光光譜，改進光譜之訊雜比約10倍，並延伸觀測範圍由振動能量3500 cm-1至6000 cm-1。不僅由HC35Cl及DC35Cl的螢光分光光譜觀測到更多基態振動能階，也首次取得HC37Cl及DC37Cl之螢光分光光譜。我們分別觀測到HC35Cl及HC37Cl各18和17個基態振動能階，以及DC35Cl及DC37Cl各24個基態振動能階，而且首次觀測到HCCl之C-H拉伸振動頻率，即 為2971 cm-1。此外，由於我們直接觀測到 譜線，所以精確地決定HCCl相對於 之單重態與三重態之能階差(ΔEST)為2167 cm-1 (6.20±0.05 kcal/mol)及DCCl之單重態與三重態之能階差(ΔEST)為2187 cm-1 (6.25±0.05 kcal/mol)。而在雷射誘導螢光激發光譜方面，我們也首次標示(assign) HC37Cl 及 之轉動結構，而且發現DCCl 之新譜帶。 New dispersed flourescence spectra following the exciteation of several A-X bands of HCCl and DCCl at visible wavelengths were successfully acquired in a discharge supersonic free jet expansion using an intensified charge-coupled device (ICCD) detector. We extended the ground singlet state vibrational assignments of HC35Cl and DC35Cl from 3500 to 6000 cm-1 and observed the DF spectra of HC37Cl and DC37Cl for the first time. Complete vibrational parameters of the HCCl and DCCl ground singlet state were determined. The singlet-triplet energy gap from the zero-point level could be determined to be 2167 cm-1 (6.20±0.05 kcal/mol) in HCCl, and to be 2187 cm-1 (6.25±0.05 kcal/mol) in DCCl. Additionally, some new data of the A-X excitation spectrum are reported for HCCl and DCCl.
