Date of Award
College of Science
Type of Degree
B. Scott Day
Dendrimers are hyperbranched polymers with a tree-like structure that can be tuned for size, shape, and functionality. Dendrimers have exhibited numerous possibilities in chemical and biochemical processes as their use in host-guest systems and controlled gene and drug delivery vehicles. Distinct properties of dendrimers, such as well-defined architecture and high ratio of functional moieties to molecular volume, make these polymers substantially useful for the development of nanomaterials and medicines. It has recently been demonstrated that polypropylene-imine (PPI) dendrimers have specific physical properties that are well suited for many applications. More specifically, the nitrile-terminated dendrimer creates a unique environment that is both aprotic and polar. Increasing interest in the design and use of these dendrimer systems has created a need for new methods of physical and chemical characterization. The current techniques used for characterization tend to be slow and sample limited, even for monodisperse samples. Polydisperse samples are even more analytically challenging. This thesis used a rapid and precise analytical framework for the characterization of dendrimers by systematically probing the electrospray ionization mass spectrometry (ESI-MS) speciation and the gas-phase collision-induced dissociation (CID) fragmentation patterns for early generation (PPI) dendrimers. Two isotopically labeled dendrimer species were employed for unambiguous assignment of complex structures and mechanisms. Hypothesized mechanisms were verified, while one anomaly presented for the β-labeled dendrimer. Also, the fragmentation patterns of certain alkali and alkaline earth metal-dendrimer complexes were investigated. These complexes of +1 and +2 charges exhibited similar losses, including radicals.
Chemistry, Physical and theoretical.
Bott, Hannah Elizabeth, "Probing a Complex Dissociation Energy Surface with Experimental and Theoretical Methods" (2015). Theses, Dissertations and Capstones. 932.