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...