Two dendrimer cores that contain o-nitrobenzyl photolabile moieties have been synthesized from piperonal. Methylated core analogs undergo clean photocleavage as indicated by the evolution of isosbestic points in the UV spectra during photolysis and the observation of degradation products by ¹H NMR. These dendrimer cores serve as precursors to dendrimer-based photodegradable materials. Second generation benzyl aryl ether dendrimers have been synthesized and undergo clean photocleavage as indicated by the evolution of isosbestic points in the UV spectra during photolysis and the observation of degradation products by ¹H NMR. Two oligomeric models of disassembling dendrimers have been synthesized from vanillin and o-vanillin. The first system tests the para cleavage vector while the latter test cleavage through the ortho vector of dendrimer disassembly. These systems are used to test potential trigger groups prior to dendrimer synthesis due to their ease of synthesis. Each system shows clean cleavage when triggered by an allyloxy or o-nitrobenzyloxy trigger group as indicated by the evolution of isosbestic points in the UV spectra during disassembly and the observation of disassembly products by ¹H NMR. Dendrimers with a 2,4-branching motif have been synthesized. These dendritic systems have been triggered with and allyloxy group and undergo disassembly via both the ortho and para cleavage vectors simultaneously. Cleavage was noted by the evolution of an isosbestic point in the UV spectra during disassembly.

Supramolecular assemblies are composed of noncovalently associated molecules which organize in water to yield 2-D and 3-D architectures. Crosslinking polymerization of supramolecular assemblies provides an effective means to modify their chemical and physical properties. Two methods of characterizing crosslinked polymeric assemblies were developed. These techniques rely on experimentally observed changes in polymer solubility and assembly stability in the presence of nonionic surfactants. The results show an inefficient crosslinking mechanism in organized media compared to isotropic polymerization. Two models rationalizing the inefficient crosslinking observed in organized media were proposed. Symmetrical crosslinking agents were synthesized to test the models. These results suggest intramolecular memorialization is an important process in the efficiency of crosslinking. The polymerization of a heterobifunctional lipid with two polymerizable groups in the same acyl chain separated by a six carbon spacer yielded a novel linear ladder-like polymer architecture. The two reactive groups are in regions of different polarity allowing for the simultaneous, selective, and sequential polymerization depending on the initiation chemistry employed. A second heterobifunctional lipid was designed and synthesized with a longer spacer between the two reactive groups. Polymerization of vesicles gave stable polymeric vesicles. The results from the crosslinking and redox polymerization studies on 2-D assemblies were applied to the inverted hexagonal and bicontinuous cubic phases. Phase behavior is characterized before and after crosslinking polymerization principally by variable temperature ³¹NMR. γ-Initiated polymerization of bis-lipids was studied to evaluate their sensitivity to ionizing radiation. The reactive moiety effects the initial rate of polymerization, extent of polymerization, and inhibition by oxygen. A preliminary investigation of polymerizable ion-paired amphiphiles (IPA) showed polymerization methods commonly used for zwitterionic lipids can be applied to IPA. This is the first report of polymerization of reactive groups in the anionic acyl chain of an ion-paired amphiphile.

The synthesis of bicyclobutane and cyclobutene monomers has been studied for the past 30 years. The polymers of these monomers have shown to possess superior properties in comparison to their linear analogs. Current synthetic methods used for the preparation of bicyclobutane and cyclobutene monomers require high temperature, high pressure, a large number of steps, and handling of toxic materials. Generally the synthetic methods employed have given very low yields. Dipolar [2+2]-cycloaddition reactions between alkenes take place spontaneously when one alkene contains strong donor substituents and the other strong acceptor substituents. Our general synthetic scheme involved a [2+2]-cycloaddition to form cyclobutane derivatives containing an acidic proton at C₃ or C₂ and an electron donating substituent at C₁. Following transformation of the donor substituent to a leaving group, bicyclobutanes or cyclobutenes were formed by 1,3- or 1,2-elimination. Phosphite, acetal, and amide as electron-donor substituents in [2+2]-cycloaddition reactions with cyano- or ester-substituted electrophilic alkenes form a variety of cycloadducts.

The surface properties of quaternized poly(styrene-block-4-vinylpyridinium) AB block copolymers in monolayers spread at the air/water interface were thoroughly studied using the Langmuir film balance technique and microscopy techniques (i.e. transmission electron microscopy and atomic force microscopy). The effects of both molecular structure (i.e. chain lengths of the two blocks, alkyl chain length, and the counterion of the quaternizing agent) and the experimental parameters (i.e. measurement temperatures, salt species and salt concentrations in the aqueous subphase, compression rates, and hysteresis) on interfacial behaviour of the ionic block copolymers were explored. Optimum conditions for the deposition of polymer monolayers from a water surface to a solid substrate for the microscopy studies were also investigated. Evidence for novel surface micelle formation is presented. Three morphologies of surface micelles (i.e. plane, rod, and starfish) are identified for the block copolymers. The appearance of each morphology is found to be related only to the relative chain lengths of the two blocks. Methods of calculating aggregation numbers in starfish micelles are developed. A phase transition phenomenon is observed in surface pressure-area isotherms of the polymer monolayers. This phase transition is found to be related to the pressure-induced solubilization process of the quaternized poly(4-vinylpyridinium) hydrophilic block chains. A model of a starfish-to-jellyfish transition is introduced to describe this phase transition phenomenon.

Kevlar fibers are known for their high strength. We have fluorinated these fibers in an attempt to increase their working temperature. Analysis shows that we are able to fluorinate a substantial amount of the aromatic ring, but loss to mechanical and thermal stability accompanies this. In the past, doping of polyacetylene film has shown to increase its conductivity by several orders of magnitude. In our efforts, we are also able to increase the conductivity of these films through direct fluorination. Our highest conductivity increase is approximately one order of magnitude. The fluorinated films show no increased resistance to air oxidation.

<p> This dissertation reports the synthesis and characterization of nanoscale coordination polymers (NCPs) for anticancer drug delivery. Nanoparticles have been explored in order to address the limitations of small molecule chemotherapeutics. NCPs have been investigated as drug delivery vehicles as they can exhibit the same beneficial properties as the bulk metal-organic frameworks as well as interesting characteristics that are unique to nanomaterials. </p><p> Gd-MTX (MTX = methotrexate) NCPs with a MTX loading of 71.6 wt% were synthesized and stabilized by encapsulation within a lipid bilayer containing anisamide (AA), a small molecule that targets sigma receptors which are overexpressed in many cancer tissues. Functionalization with AA allows for targeted delivery and controlled release to cancer cells, as shown by enhanced efficacy against leukemia cells. The NCPs were doped with Ru(bpy)₃²⁺ (bpy = 2,2'-bipyridine), and this formulation was utilized as an optical imaging agent by confocal microscopy. </p><p> NCPs containing the chemotherapeutic pemetrexed (PMX) were synthesized using different binding metals. Zr-based materials could not be stabilized by encapsulation with a lipid bilayer, and Gd-based materials showed that PMX had degraded during synthesis. However, Hf-based NCPs containing 19.7 wt% PMX were stabilized by a lipid coating and showed in vitro efficacy against non-small cell lung cancer (NSCLC) cell lines. Enhanced efficacy was observed for formulations containing AA. </p><p> Additionally, NCP formulations containing the cisplatin prodrug disuccinatocisplatin were prepared; one of these formulations could be stabilized by encapsulation within a lipid layer. Coating with a lipid layer doped with AA rendered this formulation an active targeting agent. The resulting formulation proved more potent than free cisplatin in NSCLC cell lines. Improved NCP uptake was demonstrated by confocal microscopy and competitive binding assays. </p><p> Finally, a Pt(IV) oxaliplatin prodrug was synthesized and incorporated in different NCPs using various binding metals. A moderate drug loading of 44.9 wt% was determined for Zr-based NCPs. This drug loading, along with a diameter less than 200 nm, make these particles promising candidates for further stabilization via lipid encapsulation.</p>

The research presented in this thesis is focused towards applying Surface-Initiated Atom Transfer Radical Polymerization (SI-ATRP) for the synthesis of functional biomaterials. ATRP is a method of living radical polymerization which gives control over the polymer chain length and the end group. SI-ATRP is carried out after immobilization of the molecules that initiate ATRP on surfaces (Gold, Glass, and Silicon). When a surface modified with the initiator molecules is exposed to polymerization solution, the resulting polymer chains are covalently bound; yielding a densely grafted polymer brush. I have developed the SI-ATRP of commercially available oligo(ethylene glycol) methacrylate (OEGMA) monomers to prepare nanoscale poly(OEGMA) coatings that expose PEG chains in high surface density. Protein adsorption for plasma proteins (lysozyme, fibrinogen, and albumin) as measured by XPS shows that, these coatings exhibit remarkable resistance against protein adsorption that depends on the attributes of the monomer. Polymer films thicker than 3 nm are effective in retarding protein adsorption with the level of proteins adsorbed on these films being 99.4% less than that on a bare Silicon surface. I have also evaluated the effects of chain length and end group of the monomers on the kinetics of their polymerization and the wettabilities of the resulting films. Poly(NiPAAm) gels that exhibit a thermal phase transition at 32&deg;C have been widely studied for possible applications in drug delivery systems. I have applied SI-ATRP to synthesize diblock, random, and gradient copolymer brushes of NiPAAm and OEGMA with a goal to obtain polymeric films with an outer biocompatible surface and an inner bulk capable of swelling-deswelling transition. XPS and wetting studies are employed to characterize these coatings. Reactivity ratios in the copolymerization of NiPAArn and OEGMA through SI-ATRP are determined by application of the Mayo-Lewis terminal model of copolymerization. Observed monomer reactivity ratios---r1 (for NiPAAm) and r 2 (for PEGMA, MW 300)---are 0.07 and 3.85, respectively. Finally, the techniques developed above are applied to create a nanoscale device capable of photothermally triggered drug release. Nanoshell-PNiPAAm hybrids are synthesized by SI-ATRP of NiPAAm on gold nanoshells and characterized by XPS and TEM.

Emission at the Na D lines has previously been observed from the intersection of crossed effusive beams of K and NaCl irradiated by a dye laser at wavelengths form 590nm to 735nm. The three beam signal is attributed to direct photoexcitation of KClNa transition region species. Further interpretation of these experiments is hampered, however, by broad translational and internal energy distributions of reacting partners. Supersonic beams of K and NaCl, both seeded in argon, were developed in order to reduce the distribution of translational and internal energies. It was hoped that insight into the reaction dynamics of the K+NaCl system would be revealed by the difference in collision energy between crossed effusive beams and crossed seeded beams. In addition, the rotational broadening of the K$\sb2$B$\sp1\Pi\sb{\rm u}$-X$\sp1\Sigma\sb{\rm g}\sp{+}$ spectrum collapses on cooling and therefore "artifact-clean" frequencies could be probed by the laser. Extensive characterization studies of the seeded beam sources were carried out. Mean velocities of K and NaCl were measured to be 1.3 $\times$ 10$\sp5$ and 1.1 $\times$ 10$\sp5$ cm/sec, respectively. Measurements of the rotational and vibrational energy distributions of K$\sb2$ present in the potassium beam reveal a rotational temperature of 12 $\pm$ 1$\sp\circ$K and vibrational temperature of 77 $\pm$ 13$\sp\circ$K. Time of flight experiments demonstrate a translational temperature for NaCl and K beams of 170$\sp\circ$K and 12$\sp\circ$K, respectively. Significant three beam emission at the 589.0nm Na D line is observed at the intersection of crossed seeded reagent beams of K and NaCl irradiated by a dye laser from 610nm to 750nm. This three beam signal is comparable to that previously observed with effusive sources. However, contrary to expectations the photoluminescence of the K beam at 589.0nm when laser excited in the region 610-750nm was much larger than for an effusive source. The seeded source potassium photoluminescence at 589.0nm is an order of magnitude larger than the seeded source three beam signal. In contrast, the three beam signal with an effusive K beam is substantially the largest signal in that system. Nevertheless, the narrow energy distribution of these supersonic sources and their ability to change the collision energy makes them very useful for further probing of the KClNa transition region species.

Triscycloproparenes 1 and 2 were synthesized by treating the Diels-Alder adducts of 1-bromo-2-chlorocyclopropene and either hexaradialene (3) or hericene (4) with potassium t-butoxide. New cycloproparenes 5 and 6 were also isolated using this approach.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) The thermolysis of cyclopropa (b) naphthalene with C$\sb{60}$ was investigated and was found to yield a new Fullerene adduct. The biradical addition was also performed with $\sp3$He labeled Fullerene, and the product (7) was studied by $\sp3$He NMR.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) Silver (I) catalyzed reactions of several cycloproparenes were also investigated. In the absence of nucleophilic protic solvents or other reactants, benzocyclopropene (and its derivatives) could be dimerized to yield linearly fused six-membered rings as illustrated by the reaction of cycloproparene 8. Further aromatization of the dimers could be achieved (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI) using DDQ in benzene. This technique was also employed with biscycloproparenes such as 11 and the new triscycloproparenes to obtain ladder polymers and more intricate nonrandomly cross-linked polymers.(DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI)

Experiments using the laser vaporization technique for production of metal clusters have been performed. The reactions of neutral metal clusters with various gases have been studied using a fast flow reactor. Dramatic reactivity variations were observed which depended on cluster size, metal, and reactant. A laser vaporization disc source has been developed for the study of semiconductor clusters. Some preliminary studies on neutral germanium and silicon clusters were performed. Their ionization potentials have been bracketed and the clusters were found to fragment by a fissioning process and to have long lived (100 nanoseconds) excited electronic states. A detailed study has been undertaken into carbon clusters. Laser synthesis of astrophysically important polyyne molecules such as H-C-(C-C)$\sb{\rm 2n}$-N has been done. Chains containing up to 22 carbon atoms are formed in a vaporized carbon and reactant gas plasma. A photophysically stable and chemically inert cluster, C$\sb{60}$, has been discovered and hypothesized to have the structure of a truncated icosahedron. All even clusters in the 60 atom size range were found to be inert to highly reactive gases, while odd clusters readily reacted. The results are consistent with a whole series (30-90 atoms) of closed cage-like structures. Closure of even clusters only is possible via the inclusion of twelve pentagons into a hexagonal network. Odd clusters show neither the photophysical nor chemical stability of the even clusters. A mechanism for the formation of spherical soot particles has been developed. Stable organometallic complexes of the formula C$\sb{\rm 2n}$M (20 $<$ n $<$ 40 and M = La, Ba, Sr, Ca) have been laser synthesized. The dominant complex observed was C$\sb{60}$M$\sp+$. These species are photophysically stable, chemically inert, and no C$\sb{\rm 2n}$M$\sb2$ species were detected. The ultraviolet and visible absorption spectrum of C$\sb{60}$ has been measured. Because excited electronic states are not expected to live long in a molecule of this size, a unique spectroscopy independent of excited state lifetime was developed. Predissociation spectroscopy was performed on the cold van der Waals complexes C$\sb{60}$--CHCL$\sb2$ and C$\sb{60}$--benzene. A single sharp (50 cm$\sp{-1}$ wide) absorption band was found at 3860 A and 3863 A for the two complexes respectively. This peak is tentatively assigned to the 0-0 band of the lowest $\sp1$T$\sb{\rm 1u}$ $\gets$ $\sp1$A$\sb{\rm g}$ (LUMO+1 $\gets$ HOMO) transition of a truncated icosahedral carbon shell structure.