Synthesis and Titration Studies of Redox-Active Arylazothioformamide Ligands with Various Transition Metals
Additional Funding Sources
The project described was supported by a University of Idaho Chemistry Departmental Scholarship.
Abstract
Due to the large amount of e-waste generated every year, incredible amounts of precious metals are thrown into landfills. Additionally, many extraction techniques require destructive and/or toxic methods to mine and/or recycle such materials. There is a need for a mild lixiviant alternative. The N,N-diethylphenylazothioformamide (ATF) ligand has been shown capable of coordinating and dissolving solid metals and has potential for selectively removing, recycling, and purifying metals. ATF ligands are redox-active, behaving in innocent or non-innocent manners and display weak binding coordination with transition metals and their salts. Because the ATF ligands have a straightforward synthesis and the opportunity of steric and electronic diversity, a small assortment of ATF derivatives has been created. Following purification and full characterization, these ligands have in turn been studied through 1H NMR and UV-Vis titration as well as through computational modeling of X-ray crystal structures and advanced equilibrium models to determine their binding coefficients. By changing the different electron withdrawing/donating groups, the observed binding constants and crystal structures differ from the expected. This presentation will discuss how the experimental and computational data can be used to further understand the ligands’ behaviors and obtain association constants in simple (1:1) and complex (2:1) binding systems.
Synthesis and Titration Studies of Redox-Active Arylazothioformamide Ligands with Various Transition Metals
Due to the large amount of e-waste generated every year, incredible amounts of precious metals are thrown into landfills. Additionally, many extraction techniques require destructive and/or toxic methods to mine and/or recycle such materials. There is a need for a mild lixiviant alternative. The N,N-diethylphenylazothioformamide (ATF) ligand has been shown capable of coordinating and dissolving solid metals and has potential for selectively removing, recycling, and purifying metals. ATF ligands are redox-active, behaving in innocent or non-innocent manners and display weak binding coordination with transition metals and their salts. Because the ATF ligands have a straightforward synthesis and the opportunity of steric and electronic diversity, a small assortment of ATF derivatives has been created. Following purification and full characterization, these ligands have in turn been studied through 1H NMR and UV-Vis titration as well as through computational modeling of X-ray crystal structures and advanced equilibrium models to determine their binding coefficients. By changing the different electron withdrawing/donating groups, the observed binding constants and crystal structures differ from the expected. This presentation will discuss how the experimental and computational data can be used to further understand the ligands’ behaviors and obtain association constants in simple (1:1) and complex (2:1) binding systems.
Comments
T60