Metal Organic Framework Formation from Flexible, Heterochelating Ligands and HPLC Characterization of Self-Assembling Multimetallic Duplexes

Open Access
- Author:
- Kapelewski, Matthew Thomas
- Area of Honors:
- Chemistry
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Mary Elizabeth Williams, Thesis Supervisor
Przemyslaw Maslak, Thesis Honors Advisor
Thomas E Mallouk, Faculty Reader - Keywords:
- chemistry
inorganic
HPLC
metal organic frameworks - Abstract:
- Control over the self-assembly of materials for the construction of molecular-scale electronics and artificial photosynthetic systems is highly desirable; structure dicates function, so being able to control the self-assembly of these materials will, in turn, allow for the control of the structure. The use of artificial peptides functionalized with pendant chelating groups for directed metal coordination is a useful strategy for achieving such self-assembly. The “inorganic DNA,” or iDNA system introduced by our group has been previously shown to utilize an aminoethylglycine backbone with pendant pyridine-based ligands. These pyridine-based ligands afford opportunities for self-assembly: in the presence of metal ions, double-stranded duplex structures can be formed. The synthesis of pyridine-phenyl terpyridine dipeptides and their corresponding, self-complementary duplexes is described. The use of high performance liquid chromatography is then applied to these iDNA duplexes to illustrate the difference between the duplexes and their single-stranded dipeptide counterparts based on charge and also to verify the purity of each of these samples. Metal-organic frameworks are a second self-assembling system that creates extensive, porous framework materials that have applications in gas storage, separations, and catalysis due to their high porosity and internal surface area. In this thesis, the application of iDNA monomers to metal-organic frameworks is described. Structures based on a diacid bipyridine monomer were synthesized with Cu2+ and Al3+. These were studied by powder X-ray diffraction, surface area and pore size analysis, IR spectroscopy, UV-Vis spectroscopy, and thermogravimetric analysis. BET analysis revealed that aluminum frameworks had surface areas as high as 140 m2/g and metal coordination to ligands was confirmed through IR analysis. Furthermore, heterometallic species containing both Al3+ and Cu2+ were prepared and characterized. These intial studies demonstrate that the flexible aminoethylglycine linker can be employed for building homo- and heterometallic porous networks that ultimately could be useful for gas storage and catalysis.