The Search of Selective Ion-Extraction Material: Metallation and Derivatization of Cyclam
Authors:Angelique Cao Minh, Vickie Nguyen, Qinliang Zhao
Mentor:Qinliang Zhao, Assistant Professor of Chemistry, University of the Pacific
1, 4, 8, 11-tetraazacyclotetradecane (cyclam), a saturated macrocylic polyamine, has a broad capability in stabilizing transition metal ions, which has led to potential applications in many fields, including catalysis, biomimicry, metal recovery, and medicine. To understand the role of cyclam in securing ions in the center, metallation of cyclam with a large selection of ions in regular solvents were conducted. It was found that cyclam was able to stabilize first-row transition metal ions easily, while hardly any desired product was isolated while cyclam reacted with heavy transition metal ions. This study led us to investigate derivatization of cyclam, which hopefully will provide hints on how ligand modification can tune its ion-extraction functions. Reactions between cyclam and aryl halides with the assistant of a scavenge base were examined at different conditions. All reactions were closely monitored by MS and NMR analyses. When the substitutes were bulky, no complete substitution was observed even after a few weeks. When aryl halides with better leaving groups were used, all four secondary amines changed to tertiary amines. Structural verification of the products and optimization of the reaction conditions are in process.