分子形貌所指示的羟基卡宾及其衍生物的质子转移反应  

Molecular Face Guiding the Proton Transfer Reactions of Hydroxyl Carbene and Its Derivatives

作　　者：赵东霞[1] 张海霞 冯文娟 杨忠志[1] ZHAO Dongxia;ZHANG Haixia;FENG Wenjuan;YANG Zhongzhi(School of Chemistry and Chemical Engineering,Liaoning Normal University,Dalian 116029,China)

机构地区：[1]辽宁师范大学化学化工学院,大连116029

出　　处：《高等学校化学学报》2021年第7期2187-2196,共10页Chemical Journal of Chinese Universities

基　　金：国家自然科学基金(批准号:21473083,21133005)资助.

摘　　要：分子形貌(Molecular face,MF)定义分子的内禀电子转折边界面,同时在其上计算并描绘出前沿电子密度(MFED).MF不仅能显示分子的形状和大小,还能够指示分子的化学反应性.应用M06-2X/6-311++G(d,p)理论方法,对单线态和三线态羟基卡宾分子及其衍生物的质子化反应进行研究并计算了这些反应的活化能.结果表明,吸电性和供电性较强的取代基,均使单线态反应活化能增大,只有吸电性较强的─CN才能使三线态反应活化能增大.应用分子形貌理论研究了上述反应,不仅展示出分子的形貌变化、与反应位点的关联,以及有关物理量的变化倾向,而且还定量地显示出,单线态羟基卡宾及其衍生物分子边界面上前沿电子密度极大值与极小值的差值,与其质子转移反应的活化能之间存在线性相关.Molecular face(MF)is a molecular intrinsic characteristic contour(MICC)with calculating and describing the electron density(ED)on it.MF not only gives the molecular boundary surface,but also shows the interaction sites and reactivity indicators,including the frontier ED(MFED).M06-2X/6-311G(d,p)level of theory was employed to study proton transfer reactions of the singlet and triplet hydroxyl carbene molecules and their derivatives and to calculate their respective activation energies.It is shown that the substitutes with the strong electron⁃withdrawing and electron⁃donating groups make the activation energies of the singlet hydroxyl carbene reaction increase,whereas the substituent─CN with the biggest electron⁃withdrawing group makes the activation energy of the triplet hydroxyl carbene reaction increase.Moreover,other substitutes with the strong electron-donating group make the activation energies of the singlet hydroxyl carbene reaction increase,whereas they make the activation energies of the triplet hydroxyl carbene reaction decrease.The strong electron-withdrawing groups make the activation energies of these reactions decrease.MF was used to explore the reactions mentioned above.Their MFs represent the changes of the molecular faces,and connect the reactive sites and change trend of the involved physical properties.There is a linear correlation of the difference between the maximum electron density around the C atom and the minimum electron density around the H atom of the singlet hydro-xyl carbene reactants and their corresponding reaction activation energies.

关 键 词：质子转移反应 活化能 单电子作用势 前沿电子密度 分子形貌 

分 类 号：O641[理学—物理化学]