Study On Electrophilic Reaction,Nucleophilic Reaction And Molecular Acidity And Basicity By Information-Theoretic Approach

In principle,electrophilic and nucleophilic are the essential features of the molecule,which are closely related to the electron gain and loss of the atoms in the molecule.Therefore,the conventional chemical knowledge holds that the distribution of atomic charges in a molecule should be sufficient to quantify these concepts.But these relationships cannot be determined independently as a result of atomic charges corresponding to the non physical observability,coupled with calculating by different methods.Acid-Base Properties is one of the important molecular activity,There are many ways to measure experimentally,nevertheless these methods are complex and complicated with many uncertainties.In theory,the study of the above three has a long history,such as the use of density functional theory(DFT)in the Fukui function as a theoretical premise,can prediction of nucleophilic reactions of electrophilic and nucleophilic attack sites,such as the use of frontier molecular orbital energy global descriptor predicted molecular pK_a value.In this paper,the research methodology of electrophilic reaction by using the density functional theory of active information,nucleophilic reaction and molecular acidity and Basicity.In this paper,the electrophilic aromatic substitution reaction types as a research object,and the amount of physical activity information theory to quantify their descriptors,the scaling properties and electron population are closely related.Electrophilic aromatic substitution is a process of atoms or groups on the benzene ring is electrophilic attack and substitution,before any connection to the benzene ring,ortho,meta substituent decided the activity and selectivity of the reaction.We try to solve this kind of electrophilic substitution reaction system on three issues:(1)to examine the information gain of entropy and Hirshfeld charges are used as descriptors for the behavior to predict the reaction energy barrier;(2)method to quantify the chemical effect in recent density functional theory activity developed under such as spatial effect as a tool.The energy barrier decomposition and determine the energy components in these reactions can occupy the dominant position in the base or there is an indispensable contribution;(3)It's found that the electronic information theory cloth physical quantity in these systems the scaling properties and molecular level in AIM(atom in molecule)and related control factors.For better understanding of this kind of important reaction,these results provide a useful information.As a continuation of recent information from the theory and method of density functional theory to quantify the amount of active chemical reactivity,in this paper,the effective information of theoretical physics quantity in double molecule in gas phase and solvent water under the condition of nucleophilic substitution reaction(S_N2).The results confirmed that the information theory of physical quantity found as before the qualitative standard of chemical activity is based.At the same time,the barrier and the electrostatic interaction has a very strong correlation,which also verified the correctness of the information theory,although the exchange correlation and the steric effect of the contribution is less significant,but is still necessary.It's also found that the other system and preliminary study of these S_N2 reactions,as selective carbon atoms of the Hirshfeld charge and the information gain can effectively predict the reaction energy barrier,and other information in the same amount of theoretical physics atoms such as Shannon entropy,Fisher entropy and Ghosh-Berkowitz-Parr entropy.These new results are profound the point of view,but also a better understanding of the influence factors of chemical reaction is one of the most important chemical conversion type.Based on the information theory method,some common monocarboxylic acids such as acetic acid,benzoic acid as the research system,the study found that there is a strong linear relationship with the amount of information of the carboxyl hydrogen acid system with the AIM level and the oxygen atom is connected,also once again demonstrated before conclusion electronic cloth scaling properties and AIM levels in the system are closely related.