Part I: Design of Photo-Responsive Molecules towards Biomedical ApplicationsThe use of light to control systems provides numerous advantages such as spatiotemporal precision, non-invasive penetration, and precise energy input. Specifically, molecules that undergo photoinduced cleavage, photoremovable protecting groups (PPGs) have emerged as an active area of research due to their broad...
Formed through self-assembly of polynuclear node clusters and multitopic organic linkers, metal–organic frameworks (MOFs) are a class of three-dimensional crystalline materials. Due to their exceptional porosity, high surface areas, amenability to construction, chemical diversity, uniformly arrayed metal-containing nodes, and highly modular nature, MOFs are an ideal class of materials for...
The discovery of abundant reserves of shale gas over this past decade has reshaped the world’s energy landscape. It has renewed interests in the activation and conversion of methane as well as other light alkanes. While the oxidative coupling of methane (OCM) and oxidative dehydrogenation (ODH) of ethane and propane...
Chemical modifications of oligonucleotides (ONs) have advanced these molecules towards clinical approvals. On their own, native ONs have poor pharmacokinetic properties, such as rapid degradation by nucleases and poor cell uptake, which limit their potential therapeutic applications. Chemical modifications of ONs can increase their stability, alter their interactions with cells,...
The development of new catalytic methodologies for the precision synthesis of carbon-carbon bonds is central to the advancement of synthetic organic chemistry. Significant focuses of these efforts are made on the enantio- and diastereoselective synthesis of carbon frameworks, especially as chemists and biologists become more aware of the impact of...
Natural gas is likely to become one of the main sources of carbon-based chemicals in the next century due to rapidly increasing natural gas production levels. This has created new incentives to find materials that are active and selective towards alkane partial oxidation reactions that are relevant for natural gas...
Thermoelectric modules that convert heat into electrical energy are attractive for improving global energy management. This thesis reports the synthesis and characterization of two new families of lead and tin chalcogenide alloys and focuses on the impact of the grain boundaries, phase segregation, and atomic vacancies on the electronic and...
The effective capture and detoxification of chemical warfare agents (CWAs) is a pressing need in the modern world. Materials are needed for both the destruction of weapon stockpiles and personal protection via fabric coatings or respirators. Attractive candidates for these applications include metal–organic frameworks (MOFs) – highly crystalline materials composed...
Self-Assembled Monolayers for MALDI-TOF Mass Spectrometry (SAMDI-MS) is a technique that combines self-assembling molecules of alkane disulfides on gold and MALDI-TOF mass spectrometry. By using well-defined monolayers with functionalizations that both prevent non-specific adsorption onto the surface and presents immobilization handles, it is possible to pull out analytes of interest,...
Molecules are highly social: they recognize one another and form bonds with those they are attracted to and repel those they are not. Some molecules establish strong bonds, while others form weak, transient associations. These interactions are ubiquitous in Nature and are integral to life. For at the basis of...
Label-free assays, and particularly those based on the combination of mass spectroscopy with surface chemistries, enable high-throughput experiments of a broad range of reactions. However, these methods can still require the incorporation of functional groups that allow immobilization of reactants and products to surfaces prior to analysis. In this thesis,...
Neurons are sensitive to the mechanical properties of their environment and show better growth, survival and differentiation when they are cultured in soft environments with mechanical properties similar to those of the brain compared to other tissues. Within the central nervous system (CNS), there is also a range of mechanical...
Organic solar cells (OSC) are a next generation solar energy technology that offers the advantages of scalable fabrication, light weight, flexibility, and earth-abundant starting materials. Despite tremendous advances in OSC power conversion efficiency (PCE) over the last decade, active layer material selection and optimization is still largely empirical. In order...
Extensive study of nanomaterial chemical and optical properties has enabled their integration into a variety of applications. However, less thoroughly investigated are the heat generation and dissipation processes of nanomaterials following optical excitation. These phenomena are of immense importance as thermal energy can distort a material’s structure, which has profound...
This thesis describes a novel demonstration of quantum teleportation, a protocol within the broader field of quantum information science, carried out by an electron transfer reaction within a molecular system. As described in Chapter 1, quantum information science has potential impacts in computation, communication, and cryptography. This field relies on...
Theoretical investigation of photochemical processes in molecules is a nontrivial task. Ab initio calculations that completely describe such processes are often intractable to perform given today’s hardware. Thus, to gain insight into common areas of interest, such as in transition metal photochemistry and organic photovoltaics, less accurate but more feasible...
The Controlled, Site-Isolated Synthesis of Polyelemental Nanostructures in Polymer Nanoreactors Pengcheng Chen Polyelemental nanoparticles are an attractive class of materials due to their potential applications, which span the fields of catalysis, plasmonics, electronics, magnetics, targeted drug delivery, and bio-imaging. However, conventional synthetic methods for such structures are limited, especially when...
Organic semiconductors have shown great promise for optoelectronic applications, particularly solar photovoltaics. Critical to their success is the ability to understand and manipulate the relationship between molecular structure and bulk properties. Substantial progress on understanding structural influences on electronic properties has been made for the conjugated polymers and small molecules...
This thesis describes fundamental photophysical studies of quantum dot (QD)-molecule complexes, aimed at discovering strategies for enhancing the efficiency of QD-photocatalyzed and QD-sensitized multi-electron catalytic reactions, for the purpose of solar fuels production. Photosensitization of molecular catalysts that are active for reactions such as the reduction of carbon dioxide or...
Organic semiconductors are an active area of research with great promise for delivering next generation electronics and clean energy technologies. As the field matures, understanding the connection between molecular structure, materials’ properties, and device performance will be critical in finding the right material for an intended application. An effective strategy...
Increasing industrialization and the resulting negative environmental impacts highlight the need to develop alternative renewable energy sources. The Sun is a massive source and organic solar cells are a growing field of study. As new materials are synthesized, the efficiencies of organic solar cells continue to grow, but without an...
This work combines the use of high-throughput mass spectrometry with peptide arrays for to monitor reactions on peptides. The Mrksich lab introduced a high-throughput, label-free, biochemical assay that relies on self-assembled monolayers on gold and matrix-assisted laser desorption/ionization mass spectrometry, termed SAMDI-MS. This dissertation introduces new applications of SAMDI-MS and...
One of the grand challenges in materials chemistry and nanochemistry is the development of functional materials through ordered, hierarchical structures using synthetic building blocks. Nature has done this through evolution of molecular components such as nucleic acids, saccharides, lipids, amino acids, and inorganic crystals. The precise spatial positioning of these...
The mammalian oocyte undergoes large fluctuations in zinc content as it matures from a prophase I arrested oocyte to a metaphase II egg and finally is fertilized to become a zygote. These changes in total zinc content are necessary for proper progression, as disruption to egg’s ability to acquire and...
Surface-enhanced Raman scattering (SERS) spectroscopy has been demonstrated to be a powerful analytical tool. Its chemical specificity, rapidity, and portability make it an attractive technique for biosensing, but its application to this field has been limited by the fundamental distance dependence of the surface-enhancement effect. Many biological molecules of interest...
Hybrid Organic-inorganic halide perovskites are emerging semiconducting materials that have shown over 23% in power conversion efficiency (PCE) for solar cells. The most prominent materials, three-dimensional (3D) perovskites, have limited scope for structural engineering and exhibit instability when encounter with moisture and heat. Here, we focus on studying the structure-property...
Many transcription factors (TFs) regulate oncogenic processes and are therefore desirable targets for drug intervention. However, few TF inhibitors have been developed to date due to a lack of specificity and few TF binding pockets. The Meade Lab has overcome these challenges by using cobalt-based complexes that disrupt Cys2His2 zinc...
Oxidation is an important process in synthesizing a broad range of useful products such as polymers, pharmaceuticals, and fine chemicals. While H2O2 is a highly attractive oxidant for oxidative chemistry due to its high percentage of oxygen and environmentally friendly water byproduct, it is often used in excess due to...
Atomic layer deposition (ALD) is a gas-phase synthesis technique employed to manufacture thin films and metallic nanoparticles of various compositions and sizes, as well as individual, isolated species on various supports. An understanding of the dynamic surface chemistry that takes place during various ALD processes is vitally important for achieving...
Metal-organic frameworks (MOFs) are a class of highly modular materials with welldefined three-dimensional architectures, permanent porosity, and diverse chemical functionalities, which show promise for a wide range of applications, including gas storage and separation, drug delivery, chemical sensing, and catalysis. Nanoparticle forms of MOFs have similar properties but are dispersible...
Photovoltaic devices containing organic semiconducting chromophores are a promising technology for the conversion of solar energy into electricity. Research into the molecular design and processing of these materials has propelled the power conversion efficiency of laboratory-fabricated organic polymer solar cells (PSCs) to over 17%, which exceeds the 10% threshold deemed...
Molecular self-assembly is a process in which molecules spontaneously form ordered aggregates, the process of which is important in the natural world, considering those ordered systems and complex architectures contained in a living cell. The goal of chemists is to design simple molecules or chemical systems that can undergo molecular...
The invention of GdIII-based magnetic resonance imaging (MRI) probes substantially expanded the capability of MRI in visualizing details in tissue. Building upon the achievement of GdIII-based complexes, more ideal probes should feature contrast that is responsive to biomarkers, such as redox status and ion concentrations. The abnormality of these biomarkers...
In the design of efficient adsorbents for the sequestration of toxic molecules and the separation of volatile organic compounds, two important criteria are: high porosity and high density of sorptive sites. The work in this thesis showcases how metal-organic frameworks (MOFs) can be used as porous adsorbent templates where many...
Proteins are a class of nanoscale building block with remarkable chemical complexity and sophistication: their diverse functions, shapes and symmetry, and atomically monodisperse structures far surpass the range of nanoparticles that can be accessed synthetically. The chemical topology of proteins that drive their assembly into higher order materials are central...
Synthesis opens the pathway to examine a plethora of complex structures. Whether the target is a naturally occurring compound or a proposed molecule never observed before, synthetic routes can be developed to help understand a variety of properties that the molecule can contain. Synthetic efforts have helped elucidate the absolute...
Recent advances in combinatorial chemistry, synthetic biology, and ‘omics’ research require high-throughput methods for performing and analyzing thousands to millions of reactions in one day. However, it is a challenge to engineer high-throughput systems that can autonomously conduct and analyze such a large number of reactions in a generalizable and...
While Li-ion batteries are currently the preferred energy storage technology, multivalent alternatives such as Mg should be considered. Magnesium metal has a high volumetric capacity and has been shown to cycle with no dendrite formation. However, the highly charged Mg2+ ion cannot easily diffuse into the oxide cathodes favored in...
The physical boundary layer, or interface, between two different phases of matter is the site of chemical and physical processes that are critical to many research fields. Many of these interfaces contain electric charge, which influences the structure and composition of the interfacial region and the interactions between the interface...
Polyolefins are the most versatile and widely used polymers worldwide. Depending on the polymer microstructure, polyolefins can exhibit a wide range of useful and tailored properties and applications. Metal-catalyzed coordinative olefin polymerization plays a center role in advancing polyolefin synthesis. This dissertation explores two strategies to modulate the polymer microstructures...
Spherical Nucleic Acids (SNAs) are unique class of nanomaterial characterized by a dense nucleic acid shell conjugated to a nanoparticle core. This radial orientation of oligonucleotides and architecture distinguishes SNAs from the components from which they are comprised. Specifically, unique chemical and biological properties emerge that are not observed with...
In this thesis, I present the development and benchmarking of several theoretical methods designed to enable the rigorous modeling of magnetic properties of molecules containing one or a few heavy atoms, particularly single-molecule magnets. The new methods use a full four-component treatment of relativity, allowing spin–orbit effects to be taken...
Oxide/aqueous and metal/metal oxide interfaces are essential for environmental remediation, catalysis, and corrosion inhibition, in addition to their potential implementation as energy transducers, consumer electronics, and coating products. While these interfaces are critically important, they are difficult to access experimentally under aqueous flow conditions. This thesis describes results obtained with...
When attached to another species (e.g. a nanoparticle), the sequence specificity of DNA can be repurposed to program interactions between such entities and to direct their formation into ordered structures. The research presented in this thesis aims to push the boundaries of structures that can be made via this approach....
Harnessing the metabolic potential of methanotrophic bacteria is a compelling strategy for the bioremediation of environmentally harmful methane gas. Methanotrophs can activate a 105 kcal/mol C-H bond in methane at ambient conditions using metalloenzymes called methane monooxygenases (MMOs). Particulate methane monooxygenase (pMMO) is a copper-dependent, membrane-bound enzyme that is the...
The work of this dissertation seeks to enhance the understanding of DNA-driven nanoparticle assembly and introduce kinetic routes to control mesoscale crystal habit and size. Chapter 1 describes the state of the art in the field of nanoparticle assembly and, specifically, DNA- mediated nanoparticle assembly, where the concept of a...
Techniques in atomic physics have delivered some of the most precise measurements ever made, with frequency measurements reaching fractional precisions of 10^18 . High precision measurements can be used to test fundamental physics, such as pursuing a variation in fundamental constants. A finite drift in measurable constants such as the...
Small molecules such as indanes, chromanes, tetralins and their derivatives play a significant role in drug discovery due to their potent biological activity. This research herein presents a facile Brønsted acid-catalyzed allylsilane annulation methodology to generate fused ring systems such as indanes. The reaction goes through a homoallylic intermediate which...
In this dissertation, efforts are detailed to utilize semiquinoid bridging ligands to impart strong magnetic coupling between metal centers. Chapter 1 introduces the synthetic challenge of realizing molecule-based magnets with high operating temperatures due to weak magnetic coupling between spin centers through large, diamagnetic ligands. An alternative strategy is described...
This dissertation develops computational models to study the optical coupling between plasmonic nanoparticles and quantum emitters. A large number of nanophotonic applications function by using either plasmon enhanced fields to enhance optical processes within quantum emitters or the sensitivity of plasmon resonances to their environment. Developing computational methods to fully...
Synthetic organic chemistry continues to be a driver in the discovery and development of new molecules for applications in biology, medicine, crop science, polymer science, and materials science. Central to the continued development of this field is the pursuit of new strategies and methods for the efficient construction of molecules...
Nonlinear optical (NLO) effects are used universally in modern day telecommunication and form the foundation of emergent photonic technologies. Twisted intramolecular charge transfer (TICT) chromophores, composed of a donor and acceptor fragment connected by a twisted bi-aryl bridge, combine large molecular NLO response with properties such as transparency in the...
Bimetallic polymerization catalysis represents a small, though active, area of research due largely to the interesting properties observed in the resulting product polymers, including higher molecular weight, increased comonomer incorporation, and enhanced tacticity. Current work is focused on furthering an understanding of the active catalytic species that give rise to...
The thermodynamics and kinetics of electron transfer reactions in catalysis, energy conversion and storage, and plasmon-driven chemistry depend strongly on nanoscale electrode surface structure. To elucidate the structure-function relationships that determine nanoscale electrochemical reactivity, it is necessary to observe electron transfer reactions one molecule at a time. Over the past...
Ultrafast, multi-dimensional coherent spectroscopy (MD-CS) has enabled scientists to probe fundamental aspects of chemical and photo-physical reactions on the nanosecond to femtosecond timescales. Using MD-CS, scientific contributions ranging from increased understanding of energy transfer in photosynthetic biological proteins to correlating the motion of electrons in semiconductors have been achieved. Concurrent...
The objective of this work has been the design of new lubricant additives to target friction in the boundary lubrication regime and the hydrodynamic lubrication regime. Modern automotive engines operate at higher temperatures and speeds than ever before, and therefore require new and more effective lubricant additives to meet higher...
Spherical nucleic acids (SNAs) are a class of structures composed of spherical nanoparticle cores that are densely functionalized with radially oriented, linear DNA. SNAs exhibit properties that are distinct from those of their linear counterparts. These constructs can readily enter cells, evade nuclease degradation, and bind complementary DNA targets with...
Self-assembled monolayers as tunable chemical platforms broadly enable the study of the interaction between biological species and synthetic surfaces. Unlike small molecule chemistry where the freely diffusible product can interact with biological targets as an inhibitor or probe, interfacial chemistry allows for the controlled and multi-valent presentation of ligands to...
Fused polycyclic scaffolds with three-dimensional complexity from an array of stereocenters compose the core structures of countless natural product families with a variety of desirable biological activity. The development of synthetic methods and strategies to afford rapid access to these structures is essential to expose a wealth of untapped biological...
Organic Photovoltaic (OPV) materials are of great interest as a low-cost material the purposes of achieving wide spread, solar energy adoption. However, a limiting factor in materials development is the ability to proactively determine the active layer thin film morphology that largely informs device performance. Thus, understanding how materials design...
Organic Photovoltaic (OPV) materials are of great interest as a low-cost material the purposes of achieving wide spread, solar energy adoption. However, a limiting factor in materials development is the ability to proactively determine the active layer thin film morphology that largely informs device performance. Thus, understanding how materials design...
The projected increase in the use of nanomaterials raises concerns about adverse impacts new technologies utilizing these materials may have on the environment. These concerns can be addressed from a chemical perspective by studying how emerging nanomaterials interact with biological systems. Fundamentally, the key interactions for nanomaterial uptake into a...
Noncentrosymmetry (NCS) is a requirement for many properties such as piezoelectricity, pyroelectricity, and nonlinear optical activity like second harmonic generation which are desirable for a variety of commercial applications. One method which has been employed to successfully synthesize NCS compounds utilizes acentric anionic groups, such as oxyfluoride metal complexes, as...
High-pressure and -temperature synthesis is a powerful tool for synthesizing new intermetallic compounds that cannot be formed using traditional solid-state syntheses. Such metastable compounds can exhibit unrivaled structural complexity, unique bonding, and unusual properties. In the simplest case, there are many binary systems in which no intermetallic compounds are known....
The diverse reactivity patterns, unique structural features imparted by the cumulated double bonds, and possibility of axial chirality have garnered allenes considerable attention in organic synthesis. Numerous methods have been described in the literature to afford optically active allenes starting from chiral starting materials, yet catalytic and asymmetric methods to...
The discovery and tailoring of new useful organic molecules for applications such as medicine and materials science is highly driven by meaningful developments in chemical methodology, and some of the most impactful advances have invoked catalysis to increase efficiency and specificity. N-heterocyclic carbenes (NHCs) have continuously occupied a prominent space...
The expanding use of nanomaterials in consumer products challenges scientists to understand the impact of these materials before their inevitable release into the environment. In the same way that the widespread use of DDT and asbestos has caused unforeseen negative impacts on both the environment and on human health, the...
Photovoltaic technology can help meet the exploding world energy demand in a sustainable and environmentally friendly way. Organic photovoltaics (OPVs) are especially attractive because they can be constructed with low-cost organic content and are amenable to high-throughput large-scale fabrication techniques. Synthetic modification of organic semiconductors has paved way for the...
My research interests, which span organic, inorganic, physical and biochemistry, have focused broadly on photo-, magneto- and redox-active molecules, especially those with potential applications in organic photovoltaics, spintronics and electronics. My research under the joint supervision of Professor Wasielewski and Professor Fraser Stoddart has concentrated upon understanding electronic and magnetic...
Starting materials for natural products, ideally synthesized using low-cost, highly active and selective catalysts, are of great interest to the pharmaceutical industry. Relevant reactions include the synthesis of 1,2-dihydropyridines, reduction of ketones/aldehydes, cleavage of esters, and reduction of amides to amines. Hydroelementation is an important catalytic process that involves H-E...
The electronic spin state (S) of metal ions is fundamental to the performance of magnets, protein cofactors, and magnetic resonance imaging (MRI) contrast agents. The ability to manipulate the spin state of transition metals allows for the development of advanced materials with emergent properties. This following chapters will introduce two...
Small hydrocarbons and their oxygenated derivatives are critical to atmospheric organic aerosol formation and growth. Secondary organic aerosols (SOAs) constitute a significant portion of total atmospheric organic aerosols, and are often generated through the oxidation of biogenic volatile organic compounds (VOCs) such as isoprene, -pinene, and -caryophyllene. Interfaces of SOA...
Contained in the following dissertation are detailed investigations regarding the thermodynamics of small molecule activation by metalloporphyrin complexes isolated within metal-organic frameworks (MOFs). Chapter 1 provides a description of the role metalloporphyrin complexes play in biological systems and the challenges associated with studying small molecule activation by metalloporphryin sites in...
Chemical probes are versatile and unique tools for biomedical research. A chemical probe is simply a selective small-molecule modulator of protein function that allows the user to ask mechanistic and phenotypic questions about its molecular target in biochemical, cell-based or animal studies. Experiments involving selective inhibitors can help delineate key...
The work presented in this dissertation examines the interplay between electron transfer reactions and electron spin in photoactive organic molecules. Organic compounds that undergo electron transfer reactions after absorbing light are important in natural photosynthesis, photobiology, and synthetic photovoltaics. These electron transfer reactions depend on the spin states of the...
The development of organic photovoltaic devices benefits from understanding the fundamental processes underlying charge generation in thin films of organic semiconductors. This dissertation exploits model systems of π-stacked chromophores such as perylene-3,4:9,10-bis(dicarboximide) (PDI) and 3,6-bis(aryl)diketopyrrolopyrrole (DPP) to study these processes using ultrafast electronic and vibrational spectroscopy. In particular, the characterization...
This dissertation describes the fundamental studies of photoinduced charge-carrier transfer from colloidal metal chalcogenide quantum dots (QDs) to surface-adsorbed molecular redox partners. In addition, we also present the use of visible-light absorbing QDs in photocatalytic applications. CdS QDs are used as photocatalysts in a C-C coupling reaction, in which no...
Three-dimensional (3D) and two-dimensional (2D) hybrid halide perovskites have emerged as front-runners in solar energy conversion applications with the potential to provide low-cost renewable energy. Being at the interface of chemistry, physics, materials science, and electrical engineering, the field of perovskite solar cells has become a top area of interest...
Bulk heterojunction (BHJ) organic photovoltaic (OPV) devices have been extensively studied to achieve power conversion efficiencies well above 10%. New research into alternative materials that allow for cheaper and more industrially viable fabrication of flexible solar cells has been at the forefront of the energy field for the past few...
Quantum information processing (QIP) is an emerging computational paradigm with the potential to enable a vast increase in computational power, fundamentally transforming fields from structural biology to finance. QIP employs qubits, or quantum bits, as its fundamental units of information, which can exist in not just the classical states of...
Plasmonic chemistry is an emerging field of research that contains great promise for new chemical reactivity, but thus far has been improperly observed. The goals of using plasmonic chemistry typically revolve around the use of nonequilibrium charge carriers that migrate to the surface of a plasmonic substrate to perform redox...
The tools of computational chemistry allow researchers to gain insight into chemical systems that would be difficult or impossible to gain experimentally. This dissertation discusses the application of several of these computational tools to chemical systems of interest. First, we present several studies of plasmon resonance in Ag nanoclusters using...
The nonlinear optical technique, second harmonic generation (SHG), is applied here for the first time to probe single and double strand DNA (ssDNA and dsDNA) chemically attached to fused quartz/water interfaces. DNA interfaces are often a critical functional component of biodetection, thus, the development of molecular biosensors requires a thorough...
Many metal ions are of critical importance in many cellular functions. The very properties of these metal ions that make them useful also make them toxic to the cell. In the course of evolution, many metal ion homeostasis systems have developed to provide balance between the necessity and toxicity of...
The focus of this thesis is the design of non-natural molecules for use in biological applications. Chapter one details a strategy to use small molecules to reactivate mutated p53, an oncoprotein that is prevalent in several types of cancer, back to its wild-type function. Wild-type p53 has the ability to...
This thesis discusses the synthesis, self-assembly, and conductivity properties of novel oligothiophene derivatives with an emphasis on how molecular structure effects the assembly. In order to facilitate self-assembly in conjugated molecules, specific non-covenant forces were included into the molecular design of several derivatives. First, an amphiphilic oligothiophene derivative consisting of...
The work described in this dissertation focuses on the development of a general approach to create nanoscale transition metal chalcogenide materials and new methods for controlling architecture of gold pyramidal structures. In the former, we used chemical nanofabrication, a combination of top-down patterning and bottom-up solid-state synthesis, to achieve control...
<span style="font-family: Calibri;">BaNa-Y is a catalyst for reduction of nitrogen oxides (NO and NO<sub>2</sub>) with added reductants at temperatures of ~200 °C. Studies were performed over BaNa-Y and related catalysts to unravel the roles that nitrates and nitrites play in determining the processes and pathways involved in NOx reduction. <o:p></o:p></span></p>...
Magnetic Resonance Imaging is a non-invasive modality that allows for deep-tissue imaging. Contrast agents decrease image acquisition time and increase the intrinsic contrast between different types of tissue. A new family of enzyme-activated contrast agents is emerging that has the ability to report on enzymatic processes in vivo. Towards this...
In this work several self-assembling PA systems containing covalent-linking functionalities have been investigated. These covalently linkable PAs were designed to probe the supramolecular structure by covalent capture of the nanofibers and also improve the mechanical stiffness of the gel-material. The diacetylene motif was the main functional group investigated because of...
Polyvalent oligonucleotide functionalized gold nanoparticle conjugates (DNA-AuNPs) possess unusual properties, which derive from their particle and oligonucleotide subunits as well as their three-dimensional architectures. This dissertation explores the role each chemical component plays in the conjugate's architecture and assembly and recognition capabilities. It also describes their application as probes in...
The overarching goal of this work is to understand nanometer scale junctions and electron transport through molecules in these junctions. Calculations detailing quantum interference in the electron transport through molecules, and the control of these features, show great potential for use as discrete electronic elements. Concurrent work on the fabrication...
This thesis focuses on the design of hybrid organic materials comprising polymers and small molecules for biodiagnostic and electronic applications. Specifically, the electrochemical and fluorescent signaling properties of terthiophene-functionalized polymers are combined with the enhanced recognition properties of DNA hybrid materials, culminating in the development of a "loaded" probe for...
π-Conjugated oligomeric and polymeric semiconductors have been the focus of intense research over the past few decades as alternatives to inorganic semiconductors for low-cost electronic applications such as organic field-effect transistors (OFETs). These materials enable vapor- or solution-phase fabrication of large-area, light-weight electronic devices, and are compatible with plastic substrates...
This work is a research effort aimed at understanding the mechanisms of single-molecule surface-enhanced Raman spectroscopy (SMSERS). In the decade since its discovery in 1997, the role of resonance Raman (RR) enhancement, the origin of blinking, and the properties of the hot spot formed at the junction of two nanoparticles...
The utilization of hydrofluoric acid for the preparation of silver vanadium oxide fluorides has been advanced for the synthesis of Ag<sub>4</sub>V<sub>2</sub>O<sub>6</sub>F<sub>2</sub> and Ag<sub>3</sub>VO<sub>2</sub>F<sub>4</sub>. Silver-rich metal oxide fluorides are important battery cathode materials due to the high reduction potential of silver vs. Li, which is made even higher by the incorporation...
The new binuclear organo-zirconium and -titanium metal complexes {2,7-di-[(2,6diisopropylphenyl)imino]-1,8-naphthalenediolato group 4 metal complexes {1,8-(O)2C10H4-2,7[CH=N(2,6-iPr2C6H3)]2}Zr2Cl6(THF)2 (FI2-Zr2) and {1,8-(O)2C10H4-2,7-[CH=N(2,6-
i 2 t
Pr2C6H3)]2}Ti2Cl6(THF)2 (FI -Ti2) are compared to the mononuclear analogues {3- Bu-2(O)C6H3CH=N(2,6-iPr2C6H3)}ZrCl3(THF) (FI-Zr1) and {3-tBu-2-(O)C6H3CH=N(2,6-
i
Pr2C6H3)}TiCl3(THF) (FI-Ti1), respectively, in ethylene polymerization and ethylene + olefin copolymerization processes. The comonomers studied...
The safe and efficient storage of hydrogen is possibly the chief obstacle to its use as a fuel on a large scale. Metal-organic frameworks (MOFs) are well poised to provide unique solutions to hydrogen storage, and gas storage in general, a result of their crystalline, porous networks that present the...
Au nanoprisms are a new type of inorganic nanoparticle that is particularly interesting because these particles can be made in high yield, are composed of a metal with well known surface chemistry, exhibit strong, architecture and environment-sensitive optical features, and have well-defined crystallographic facets. All of these features make Au...
Magnetic resonance imaging (MRI) is an advanced imaging modality that is experiencing increasing popularity in clinical and experimental settings. MRI enjoys the benefit of high-resolution, the use of non-ionizing radiation, and the ability to distinguish between soft tissues. MR imaging is enhanced with the use of Gd3+ chelated contrast agents;...