Presenter Information

Abebu Kassie, Colby CollegeFollow

Location

Diamond 145

Start Date

1-5-2014 1:00 PM

End Date

1-5-2014 2:30 PM

Project Type

Presentation

Description

This work describes our approach to the synthesis of triple-helicene and semi-fullerene using flash vacuum pyrolysis (FVP) techniques. The precursor is designed to generate a tri-acetylene that can rearrange to tri-vinylidene under high temperature FVP, which then participates in intramolecular cyclization to give triple-helicene . Based on known reactions, the semi-fullerene is anticipated to be a secondary product from triple-helicene. Preparation of precursor began with a triple Suzuki-Miyaura reaction converting 1,3,5-tri-bromobenzne into ketone-derivative. The second step of the reaction was performed by reacting the ketone-derivative with phosphorus pentachloride to make 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl. We are now subjecting 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl to FVP experiments to coax intramolecular cyclization to give triple-helicene, and possibly semi-fullerene. Structures for the ketone -derivative and 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl were confirmed using NMR spectroscopy and X-ray crystallography. Molecular modeling of these products will be performed using the Gaussian program for comparison with experimentally obtained data.

Faculty Sponsor

Julie Millard

Sponsoring Department

Colby College. Chemistry Dept.

CLAS Field of Study

Natural Sciences

Event Website

http://www.colby.edu/clas

ID

377

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May 1st, 1:00 PM May 1st, 2:30 PM

The Synthesis of Triple-Helicene and Semi-Fullerene Using Flash Vacuum Pyrolysis Techniques

Diamond 145

This work describes our approach to the synthesis of triple-helicene and semi-fullerene using flash vacuum pyrolysis (FVP) techniques. The precursor is designed to generate a tri-acetylene that can rearrange to tri-vinylidene under high temperature FVP, which then participates in intramolecular cyclization to give triple-helicene . Based on known reactions, the semi-fullerene is anticipated to be a secondary product from triple-helicene. Preparation of precursor began with a triple Suzuki-Miyaura reaction converting 1,3,5-tri-bromobenzne into ketone-derivative. The second step of the reaction was performed by reacting the ketone-derivative with phosphorus pentachloride to make 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl. We are now subjecting 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl to FVP experiments to coax intramolecular cyclization to give triple-helicene, and possibly semi-fullerene. Structures for the ketone -derivative and 2,2\-bis(1-chlorovinyl)-5-(2-(1-chlorovinyl)phenyl)-1,1:3,1\-terphenyl were confirmed using NMR spectroscopy and X-ray crystallography. Molecular modeling of these products will be performed using the Gaussian program for comparison with experimentally obtained data.

http://digitalcommons.colby.edu/clas/2014/program/5