Supramolecular coordination chemistry of phosphorus, arsenic, antimony, and bismuth with organothiolates

Abstract

The ever-expanding field of supramolecular chemistry has recently incorporated use of the main group ions. This dissertation presents a supramolecular approach to the coordination chemistry of the Group 15 elements, with a special emphasis on arsenic (As). Arsenic is ubiquitous in our environment, contaminates the drinking water of large human populations, and is a worldwide health concern. Arsenic's legendary toxicity is thought to be due to its thiophilicity and the stability of arsenic-thiolate bonds within proteins. Chapter I is a review of the current literature on the kinetics, thermodynamics, and supramolecular chemistry of the As(III)-thiolate bond and reveals that the stability and lability of the bond make it well-suited for supramolecular chemistry. The remainder of the dissertation explains our supramolecular design strategies for the As(III) ion with thiolate ligands, then expands the approach to the Group 15 elements phosphorus, antimony, and bismuth.

Chapter II presents an approach to controlling diastereoselectivity in the self-assembly of supramolecular As 2 L 2 Cl 2 macrocycles using intramolecular steric interactions. Chapter III expands upon this approach by using intermolecular steric interactions to control diastereoselectivity and dimer formation of As 2 L 2 Cl 2 macrocycles. Chapter IV gives insight into the self-assembly of these As 2 L 2 Cl 2 macrocycles by identifying several reaction intermediates and kinetic mistakes that form during the course of the reaction. In Chapter V the application of our design strategy to the heavier Group 15 elements of antimony and bismuth is shown through the presentation of E 2 L 3 cryptands (E = As, Sb, Bi). Additionally, a Group 15 "transmetallation" reaction is explained which allows, for the first time, the preparation of the elusive P 2 L 3 cryptand. Chapter VI further examines the transmetallation reaction, the solution isomerism of the E 2 L 3 cryptands, and presents three heterometallic EE'L 3 cryptands. Finally, Chapter VII briefly concludes this dissertation and provides some potential future directions for the project.

This dissertation includes co-authored material and previously published results.