Presentation Title

Exploring Mechanisms of Gold-Catalyzed Reactions Through Analysis of Inorganic Byproducts

Faculty Mentor

Michael Schmidt

Start Date

23-11-2019 8:00 AM

End Date

23-11-2019 8:45 AM

Location

225

Session

poster 1

Type of Presentation

Poster

Subject Area

physical_mathematical_sciences

Abstract

Our lab is interested in determining the mechanism of a Friedel–Crafts-like reaction catalyzed by silver hexafluoroantimonate and chloro(triphenylphosphine)gold(I). Friedel–Crafts alkylation strategies have been applied as the key C-C forming step in the synthesis of bioactive compounds. It is known that both Au and Ag are deposited as solids in the reaction vial, but that some remains in the organic solvent in which the reaction is done. Our goal is to quantitatively determine what portion of the silver and gold end up in solid and solution forms. A method of analyzing solid gold and silver was developed and verified using gold and silver wire. Silver wire was dissolved in 1:1 nitric acid and water, and gold wire was dissolved in aqua regia. The two were combined to form AgCl and aqueous [AuCl­4]-. The AgCl was filtered through diatomaceous earth. The filtrate was set aside and diluted for analysis of gold via atomic absorption. The silver chloride which was present on the filter was dissolved using a concentrated ammonia and the resulting solution was used in the analysis for silver via atomic absorption. Combining the results of atomic absorption analysis of both the filtrate and dissolved AgCl solutions accounted for all Au and Ag in the initial sample. Current work is directed at developing methods for analyzing for Au and Ag species left in the organic reaction solvent by extraction.

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Nov 23rd, 8:00 AM Nov 23rd, 8:45 AM

Exploring Mechanisms of Gold-Catalyzed Reactions Through Analysis of Inorganic Byproducts

225

Our lab is interested in determining the mechanism of a Friedel–Crafts-like reaction catalyzed by silver hexafluoroantimonate and chloro(triphenylphosphine)gold(I). Friedel–Crafts alkylation strategies have been applied as the key C-C forming step in the synthesis of bioactive compounds. It is known that both Au and Ag are deposited as solids in the reaction vial, but that some remains in the organic solvent in which the reaction is done. Our goal is to quantitatively determine what portion of the silver and gold end up in solid and solution forms. A method of analyzing solid gold and silver was developed and verified using gold and silver wire. Silver wire was dissolved in 1:1 nitric acid and water, and gold wire was dissolved in aqua regia. The two were combined to form AgCl and aqueous [AuCl­4]-. The AgCl was filtered through diatomaceous earth. The filtrate was set aside and diluted for analysis of gold via atomic absorption. The silver chloride which was present on the filter was dissolved using a concentrated ammonia and the resulting solution was used in the analysis for silver via atomic absorption. Combining the results of atomic absorption analysis of both the filtrate and dissolved AgCl solutions accounted for all Au and Ag in the initial sample. Current work is directed at developing methods for analyzing for Au and Ag species left in the organic reaction solvent by extraction.