Aromatic hydrocarbons are relatively not reactive. They have a special stability due to resonance (their pi electrons are completely delocalized).
Aromatic compounds do not undergo addition reactions, because they would lose this special stability. Alkenes, however, are much more reactive. They have electron-rich double bonds that allow them to undergo addition reactions. What is the overall mechanism of electrophilic aromatic substitution (EAS)? There are three key steps in electrophilic aromatic substitution.
First is the formation of the sigma bond from the C=C in the arene nuclophile Next is the removal of the H+ by breaking the C-H bond. Finally, the reformation of the C=C bond to the carbocation. What are the two categories of directing influences for substituents on an aromatic ring? Cite some specific examples, and briefly discuss why these substituents direct incoming groups to specific position on the ring. Ortho-para directors are groups with unshared pairs of electrons; an example of this is the amino group of aniline which directs to the ortho/para directions in a reaction.
These groups donate those unshared electrons to the pi system by resonance or inductive effect. Meta directors are non-halogenated groups which are highly electronegative than the carbon. These groups are highly deactivating groups. These groups withdraw electrons by resonance or inductive effect. What specific steps are required to synthesize 4-aminobenzoic acid from benzene? Why must the steps be conducted in a specific sequence? What is the correct sequence of steps? What are the correct reagent for each step?
The Dissertation on Cohesion And Performance In Groups: A Meta-Analytic Clarification Of Construct Relations
Sep 23, 2013 Avon Products Previous meta-analytic examinations of group cohesion and performance have focused primarily on contextual factors. This study examined issues relevant to applied researchers by providing a more detailed analysis of the criterion domain. In addition, the authors reinvestigated the role of components of cohesion using more modern meta-analytic methods and in light of ...