Document Type and Release Option
Thesis (open access)
Dr. Gary Guillet
Extended metal atom chains (EMAC) are multimetallic complexes that feature a linear metal chain with metal-metal bonds surrounded by stabilizing ligand molecules. When EMACs are formed with paramagnetic metal ions, unique magnetic properties can be derived from direct metal to metal communication. The challenge is that EMAC complexes are challenging to synthesize due to the inherent weakness of most M-M bonds and the specificity of the ligands required to stabilize EMACs. In prior work by the Guillet group, the silyl aminopyridine (SAP) ligands were observed to stabilize very unique triiron complexes, but they were inherently unstable. In other work, scaffolded N,N,N-tris(2-(2-pyridylamino)ethyl)amine or H3(py3ren) compounds were observed to form stable homo- and hetero-diimetallic complexes. This work attempted to combine these ideas to make EMACs with increased stability. More readily available alkylamines were used to synthesize 2,6-Diaminopyridine (DAm1) ligands while a derivative, 2-Bromo-6-methylaminopyridine (Am1), was used to try and synthesize a tren-based scaffolded ligand similar to H3(py3tren). The DAm1 and Am1 compounds were successfully synthesized through a pressure tube method using high heat and pressure to push the reactions forward. The reactions were monitored through TLC and characterized through 1H and 13C NMR. The percent yields for DAm1 and Am1 were 37.7% and 54.1%, respectively. The scaffolding ligand procedure had some complications due to three reactions to add the three Am1 molecules onto one tren molecule. After exploring several methods, the most promising was a modified version of the method used to synthesize H3(py3tren) and the pressure tube method used for the alkylaminopyridines. Future research will focus on this method and explore other methods to synthesize the scaffolding ligand.
Carter, Stephanie E., "Synthesis of 2-Bromo-6-Alkylaminopyridines, 2,6-Dialkylaminopyridines, and TREN Based Ligands" (2023). Honors College Theses. 873.