Cooperative behavior in functionalized graphene: Explaining the occurrence of 1,3 cycloaddition of azomethine ylides onto graphene

• Published in: Chemical physics letters 2012-10, Vol.550, p.111-117
• Main Authors: Denis, Pablo A., Iribarne, Federico
• Format: Article
• Language: English
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2012.08.062

[Display omitted] ► Cooperative behavior is responsible for the occurrence of 1,3 dipolar cycloadditions and other organic reactions. ► Reaction energies are increased up to 30kcal/mol per functional group. ► Functionalization forming infinite armchair lines is the avenue to heavily functionalize graphene. ► The band gap can be varied from 0 to 2eV!. Cycloaddition reactions onto graphene were studied by means of first-principle calculations. We found that for all reactions studied there is a cooperative behavior responsible for dramatically increasing the reaction energies. This result explains the reason why the 1,3 dipolar cycloaddition of azomethine ylides is both feasible and slow. The cooperative effect decreases in the following order: [2+2]-addition of benzynes >1,3-dipolar cycloaddition >[2+1]-cycloaddition of NH. This cooperative behavior can open new avenues to fine-tune the physical and chemical properties of graphene. Our results indicate that it is possible to fine tune the band gap of graphene from 0 to 2eV by varying the number of azomethine groups attached.