4 research outputs found

    121.6nm 에서 메틸 라디칼의 recombination에 관한 연구

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    학위논문(석사) - 한국과학기술원 : 화학과, 1991.2, [ iv, 39 p. ]A vacuum ultraviolet photolysis of methyl bromide at 121.6nm(253.1kal/mol) by using the hydrogen resonance lamp was studied over the pressure range of 1-50 Torr at room temperature. The result demonstrate the two decomposition mode, i.e., the molecular elimination of HBr to frommethylene, and the C-Br bond cleavage to form methyl radical. The major products of the reaction were found to be CH4CH_4, C2H4C_2H_4, and C2H6C_2H_6. The branching ratios between the molecular elimination and the methyl radical formation were 0.05:0.95. The scavenger effect was studued by adding HBr as a radical capture to obtain information about primary process. The pressure was also observed by adding inert gases, i.e., N2N_2 and He.한국과학기술원 : 화학과

    분자군내 이온-분자간 반응 및 라디칼-분자간 반응에 대한 입체역학적 연구

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    학위논문(박사) - 한국과학기술원 : 화학과, 1999.2, [ vii, 67 p. ]Intracluster Ion-Molecule Reactions of Methane Homocluster : The ion-molecule reactions within ionized methane clusters are investigated utilizing an electron-impact mass spectrometry. A number of ionic reaction products are observed and interpreted as series of cluster ions of the form (CH4)nX+(CH_4)_n X^{+} where X = CH4,CH5,C2H2,C2H3,C2H4,C2H5,C2H6CH_4, CH_5, C_2 H_2, C_2 H_3, C_2 H_4, C_2 H_5, C_2 H_6 and C2H7C_2 H_7, and n>0. These cluster series, except for X=C2H7X = C_2 H_7 and C2H6C_2 H_6, are interpreted in terms of known bimolecular ionic reactions as both electron impact energy and pressure dependencies. The two cluster ions with X=C2H7X = C_2 H_7 and C2H6C_2 H_6 demonstrate cluster reactions occurring easily in a solvated environment. Meanwhile, the C3H3+andC3H5+C_3 H_3^{+} and C_3 H_5^{+} ions show evidence of consecutive ionic reactions. Possible reaction paths are discussed and compared with previous works using photoionization of methane clusters and high pressure mass spectrometry. Reactions of Ground State Oxygen Atoms with CFCl=CXY (X,Y=H, F, Cl): Effect of Steric Hindrance and Direct Cleavage of Double Bond : The reactions of O(3P)O(^{3}P) with CFCl=CXY (X, Y = H, F, Cl) have been studied via chemiluminescence image technique under discharge flow conditions. The concentration profile of the O(3P)O(^{3}P) atom during reaction has been monitored using NO2NO_2 chemiluminescence imaging from the entire reaction zone by a charge-coupled device camera. The observed rate coefficients of O(3P)O(^{3}P) with CH2=CH2,CFCl=CF2,CFCl=CH2,CFCl=CFCl,CFCl=CHClCH_2=CH_2, CFCl=CF_2, CFCl=CH_2, CFCl=CFCl, CFCl=CHCl, and CFCl=CCl2CFCl=CCl_2 at room temperature are 7.38, 5.04, 4.43, 2.67, 1.57, and 1.36×1013cm3molecule1s11.36 \times 10^{-13} cm^{3} molecule^{-1} s^{-1}, respectively. The reaction behaviors have been interpreted in terms of steric hindrance of chlorine atom and change of reaction mechanism to a direct C=C bond cleavage by fluorine atoms.한국과학기술원 : 화학과
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