【摘要】：我們主要利用第一性原理計算方法和過渡態(tài)理論,圍繞“大氣中羰基化合物的相關(guān)演化問題”做研究,主要的研究分為以下兩個方面:(1)在CCSD(T)-F12A/VDZ-F12//BHand HLYP/6-311++G(d,p)理論水平下,我們計算羰基絡(luò)合物(CH_3)_2C(OH)C(O)CH_3與Cl原子的氣相反應(yīng)的反應(yīng)機理。計算結(jié)構(gòu)表明這個反應(yīng)有四個反應(yīng)通道可以進行,即在(CH_3)_2C(OH)C(O)CH_3分子上有四個不同地方的H原子(H1、H2、H3、H4)可以被Cl原子提取,形成氫鍵得到HCl。我們通過CCSD(T)-F12A/VDZ-F12//BHand HLYP/6-311++G(d,p)方法計算出每個反應(yīng)通道的能壘,對它們進行比較。這四個反應(yīng)通道的能壘分別是-0.69、-1.31、7.45和0.13 kcal/mol,從中我們可以知道最低的能壘是-1.31kcal/mol。因此,通過過渡態(tài)理論可以知道大氣中(CH_3)_2C(OH)C(O)CH_3與Cl原子的反應(yīng),Cl原子與H2的反應(yīng)最容易進行。(2)通過采用CCSD(T)-F12a/VTZ-F12//M06-2X/6-311++G(3df,3pf)方法基組,我們在理論上研究了硫酸和甲酸對乙醇醛的水解反應(yīng)的影響,即在H_2SO_4和HCOOH作催化劑的情況下,CH_2OHCHO與H_2O的反應(yīng)機理和動力學。計算結(jié)果表明,在沒有催化劑的情況下,在以H_2SO_4作為催化劑和以HCOOH作為催化劑情況下的能壘分別是39.47kcal/mol,11.09kcal/mol和14.50kcal/mol,在H_2SO_4作為催化劑和HCOOH作為催化劑,CH_2OHCHO水解反應(yīng)的能壘降低了28.38kcal/mol和24.97kcal/mol。這說明H_2SO_4和HCOOH對乙醇醛的水解反應(yīng)是有催化作用的,并且從熱力學方面來看,H_2SO_4比HCOOH催化效果更好。除此之外,我們通過具有Eckart隧道效應(yīng)校正的傳統(tǒng)過渡態(tài)理論來計算速率通道,從動力學反應(yīng)速率上可以知道,進入通道CH_2OHCHO…H_2O+X(X=H_2SO_4,HCOOH)比進入通道H_2O…X+CH_2OHCHO更快,也更加可行。
[Abstract]:We mainly use the first principle calculation method and the transition state theory to study the evolution of carbonyl compounds in the atmosphere. The main research is divided into the following two aspects: (1) at the level of CCSD (T)-F12A/VDZ-F12//BHand HLYP/6-311 G (d, p) theory, We calculate the gas phase reaction mechanism of carbonyl complex (CH_3) 2C (OH) C (O) CH_3 with Cl atom. The calculated structure shows that there are four reaction channels for this reaction, that is, there are four different H atoms (H _ 1, H _ 2, H _ 3, H _ 4) on (CH_3) _ 2C (OH) C (O) CH_3 molecules that can be extracted by Cl atoms. Formation of hydrogen bond to obtain HCl. We calculate the energy barrier of each reaction channel by CCSD (T)-F12A/VDZ-F12//BHand HLYP/6-311 G (d, p) method, and compare them. The energy barriers of these four reaction channels are-0.69, 鈮，

本文編號：2473552