| Summary: | 碩士 === 國立中央大學 === 化學研究所 === 98 === We studied the photolysis reaction of iodoform (CHI3) and iodomethane (CH3I) at various near-ultraviolet wavelengths (266 nm, 280 nm and 310 nm) by using nascent emission spectroscopy and laser-induced dispersed fluorescence spectroscopy in a flow system. Excited species including CH (A2Δ, B2Σ-, and C2Σ+) and atomic iodine were observed in the nascent emission spectrum following the photolysis of CHI3, while only CH (A2Δ) and some unknown bands were seen in the nascent emission spectrum following photolysis of CH3I. Molecular iodine (I2) was discovered in the laser-induced dispersed fluorescence spectrum following the photolysis of CHI3 as well as in that of CH3I, but the possible reaction intermediates such as CHI or CH2 cannot be found. Other experiments such as power dependence, concentration dependence and delay time measurements were carried out to verify the multiphoton photolysis mechanism. Based upon the results, I2 is formed from the collisions of iodine atoms generated from the photolysis at first photon.
|
|---|
