1. Reaction Pathways The goal being to synthesize FeL 2 HCl, there are many pathways that can be taken. The figure below represents the various attempts that were made. Synthesis via MeCN + Complex Synthesis Via H 2 and Proton Sponge Synthesis of Iron Phosphine Complexes for Small Gas Molecule Binding James Patton, Dr. David R. Tyler and Dr. Joel W. Gohdes Department of Chemistry| Pacific University | 2043 College Way | Forest Grove, OR 97116 | patt3192@pacificu.edu Acknowledgements: References: Tyler, D. R.; et. al., Inorg. Chem. 2002, 5453-65. Murdock Charitable Trust PRISM Grant National Science Foundation University of Oregon Chemistry Department Lev Zakharov Tyler Group Background Approximately 15% of United States natural gas reserves are contaminated with elemental nitrogen. As the natural gas is burned, the triple bonds of the nitrogen absorb some of the energy, lowering the natural gas’s energy density. Traditional methods of removal include cryogenic distillation and membrane separation. However, due to the similar melting points, size, and H 2 O solubilities, N 2 and CH 4 separations can be costly and ineffective. A solution to this problem is to use water soluble small gas molecule binding iron phosphine (FePhos) complexes. The natural gas can be purified using a pressure swing absorption. These FePhos compounds, however, decompose when exposed to water or oxygen gas. Thus, all chemistry was performed either in a nitrogen atmosphere glove box or in sealed, pressurized containers. TeSt Ligand Synthesis and Characterization N2N2 CH 4 Radius (Å)2.492.58 Boiling Point (K)77112 H 2 O Solubility (x 10 -5 )1.32.8 Abstract: Small gas molecule binding complexes have important applications ranging from understanding ammonia formation in the nitrogen cycle to separating N 2 impurities from natural gas. A series of trans-octahedral iron(II) complexes were synthesized containing a bis bidentate phosphine derivatized with 4-vinylbenzyl groups, called the TeSt ligand. Beginning with the FeL 2 Cl 2 complex, a series of reactions were mapped out to afford a wide range of trans-axial ligand substitution patterns. The compounds were characterized spectroscopically and two were characterized via x-ray crystallography. Summary of NMR Shifts of TeSt Complexes FeL 2 Cl 2 Crystal Structure FeL 2 HCl Crystal Structure Conclusion We were able to synthesize the hydride/chloride iron phosphine complex, but were not yet able to do so with high enough yield or purity to copolymerize the complex with EGDMA and MMA. Future goals for the project include measuring the H 2 and N 2 binding properties of the already polymerized dichloride complex and the yet to be polymerized hydride/chloride complex, characterize the polymers, and to further characterize other complexes in the reaction scheme such as FeL 2 HN 2 + and FeL 2 Cl + Tyler, D. R.; et. al., Inorg. Chem. 2002, 41, 5453-65. CH 4 solubility N 2 solubility High pressure Low pressure Compound 31 PHydride 1 H DVBPE-13.5- FeL 2 Cl 2 69.5- FeL 2 HCl87.6-29.8(q) FeL 2 H(H 2 ) + 86.7-10(br), -14(q) FeL 2 H(N 2 ) + 77.6-17.3 FeL 2 H(MeCN) + 83.5-23.0 31 P{ 1 H} 31 P 1H1H 31 P{ 1 H}, 36+ hrs 31 P{ 1 H} 31 P 1H1H 31 P{ 1 H} 1H1H