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...
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...
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...
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...
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...
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...
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...
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 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...
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....
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...
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...
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...
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...
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...
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...
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...
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 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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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...
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,...
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...
Raman spectroscopy is an analytical technique that utilizes inelastic scattering of light to obtain structural information of analyte molecules. The weak intrinsic process of Raman scattering, however, can be greatly enhanced when molecules are placed on or near a surface of noble metal with nanostructures. Discovered over 40 years, surface-enhanced...
The objective of molecular imaging is to noninvasively visualize biochemical events in a living system at the cellular level. Magnetic resonance imaging (MRI) is a promising modality for this goal due to its excellent resolution, unlimited depth penetration, and absence of harmful ionizing radiation. MRI techniques frequently use Gd(III)-based contrast...
This dissertation describes investigations into the two primary mechanisms by which the optical bandgap of colloidal quantum dots (QDs) may be post-synthetically modified: (i) by the quantum-confined Stark effect and (ii) by exciton-delocalizing surface capping ligands. This work demonstrates that through the use of ligand-exchange strategies that enable either of...
It is said across numerous disciplines, from biology to architecture to software engineering, that “form ever follows function.” This adage highlights the intimate relationship between structural characteristics and functional properties in many disparate fields of work. Here, we discuss how the catalytic activity and compressibility of metal–organic frameworks (MOFs) are...
Deciphering the targets of axonal projections plays a pivotal role in interpreting neuronal function and pathology. Neuronal tracers are indispensable neurobiology tools for elucidating advanced functions and interactions between different subregions of the brain. Commercially available neuronal tracers include small molecule dyes, viruses, and synthetic nanoparticles. Among these options, viral...
Total synthesis of natural products provides an avenue for investigation of complex chemical scaffolds, not only delivering access to biologically impactful molecules but also lending a deeper understanding of their inherent chemical reactivity. Expansion of reaction methodology, optimization of biological activity, and absolute structural confirmation can all be accomplished via...
Organic chromophores show great promise for energy and optoelectronic devices, due to their synthetic tunability and low production costs. In order to achieve this potential, their fundamental photophysical processes must be better understood. It has long been documented that chromophore packing at the molecular level has dramatic effect on electronic...
Cyclodextrin-based polymers (CDPs) are adsorbents based on supramolecular receptor chemistry and have emerged as a promising technology for organic micropollutant remediation. Micropollutants are small organic molecules which contaminate water systems from human related activities. The occurrence of micropollutants in water sources is associated with many negative health, economic, and ecological...
This dissertation describes the study of photoinduced charge transfer between QDs and molecular acceptors as a probe of the defects within ligand shells of QDs and as means to photocatalyze redox reactions. For charge transfer reactions to occur between QDs and molecules in bulk solution, the molecules must interact with...
A fundamental understanding of the photophysics involved in solar energy capture and conversion is crucial to the development of carbon-neutral energy technologies. Taking inspiration from nature, the photosynthetic reaction center (PSRC) is often modeled by simpler versions of its elements to allow for better control over the system and for...
Over the past 15 years, there have been significant developments in expanding the singlet fission (SF) library and understanding the SF mechanism. SF has been a topic of interest in recent years due to its potential applications in organic photovoltaics. During SF, a singlet exciton energetically down-converts into two triplet...
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...
Despite prevention and treatment, substantial risk for cardiovascular disease(CVD) remains in the population and CVD has been the leading global cause-of-death in past years.While high-density lipoprotein (HDL) markers such as HDL cholesterol (HDL-C) and HDL efflux (a cholesterol-transport-function assay) are associated with decreased risk of CVD, the mechanism of this...
Continuous and coordinated materials discovery efforts have amassed a wealth of knowledge concerning many general classes of materials. The number of known phases of all structure-types, however, is far less than number of possible materials dictated by the elements on the periodic table. Recently, with improved computational abilities and well-developed...
This dissertation seeks to explore how physical forces, notably through the use of magnetic nanoparticles and applied fields, can influence the structural outcomes of colloidal crystals engineered with DNA. Chapter 1 describes how both DNA and magnetic fields can direct the assembly of nanoparticles into periodic and sometimes crystalline materials....
The lanthanides, with their limited orbital effects and high oxophilicity, represent a class of catalytic metals highly distinguished from more commonly-utilized transition metals. Homogeneous lanthanide catalysts often afford high catalytic rates and impressive selectivity. However, challenges regarding the synthesis and utilization of highly air- and water-sensitive organo-lanthanide complexes have limited...
Electrochemical cell devices are increasingly being sought for energy conversion and storage applications due to their high efficiencies and their potential for operating free of greenhouse gas (GHG) emissions. Solid Acid Electrochemical Cells (SAECs), which most commonly employ CsH2PO4 (CDP) as the electrolyte component, are uniquely suited to meet the...
This dissertation investigates the use of organic and semiconductor nanomaterials as chromophores in solar fuels production and energy transfer-mediated [2+2] cycloadditions. A series of novel N-annulated perylene chromophore amphiphiles was synthesized via a modular synthesis. These perylene amphiphiles were found to self-assemble in aqueous solution, forming extended ribbon-like nanostructures that...
Discrete molecules, linear and branched polymers, and disordered cross-linked networks are well studied objects of chemical synthesis. However, two-dimensional polymers (2DPs) have been long missing from this continuum of molecular architectures, both in chemical synthesis and in Nature. Recently, new polymerization strategies and characterization methods have enabled the unambiguous realization...
Quantum dots (QDs) are promising photocatalysts due to their large extinction coefficient, large surface area-to-volume ratio, and stability upon irradiation. QDs have been studied in photocatalytic hydrogen production, CO2 reduction, and reduction of small organic molecules such as nitrobenzene. This dissertation describes the application of QDs in two photocatalytic cross-coupling...
Mixed-dimensional heterojunctions between two-dimensional (2D) materials and organic semiconductors is a rapidly growing field. This is motivated by the promise of leveraging the extraordinary properties of 2D materials with the synthetic tunability and reconfigurability of organic electronics, allowing the realization of new physics or devices that are not possible in...
In the first two decades of the 21st century, metal organic frameworks (MOFs) have attracted much attention in both fundamental-research and-industrial application areas. Derived from a vast library of both inorganic metal nodes and organic linker bridges, MOFs are crystalline materials whose structures and chemical environments can both be tuned...
Chirality and polarity describe orthogonal mechanisms of inversion symmetry breaking, which is the origin of valuable properties in crystalline materials including nonlinear optical activity, ferroelectricity, and piezoelectricity. Noncentrosymmetric (NCS) materials have numerous applications yet opportunities remain for cooperative coupling between chiral and polar basic building units to realize high-performance materials....
The opposing activities of phosphatases and kinases determine the phosphorylation status of proteins, yet kinases have received disproportionate attention in studies of cellular processes, with the roles of phosphatases remaining less understood. This dissertation describes the use of self-assembled monolayer laser desorption/ionization mass spectrometry (SAMDI-MS) together with peptide arrays to...
Two-dimensional (2D) covalent organic frameworks (COFs) are a class of crystalline polymer networks that polymerize and crystallize into layered structures, characterized by their atomically precise structure, permanent porosity and high modularity. Imine-linked COFs are one of the most important and promising classes of macromolecular sheets, which form by the condensation...
Molecular-oriented single-site heterogeneous catalysis is a powerful approach to address the long-lasting challenge of the structure-activity relationship in catalysis, as it allows molecular level control of the catalytic centers and thus the elucidation of reaction mechanisms. In this dissertation, single-site molybdenum-dioxo species have been immobilized on carbon supports, i.e. activated...
The idea that structure determines the properties of a material is a powerful concept in chemistry and in all fields in which chemistry is important, including engineering, medicine, and materials science. My research aims to better understand the structure-property relationships of a class of materials known as metal–organic frameworks (MOFs)....
Two-dimensional (2D) covalent organic frameworks (COFs) are a class of crystalline polymer networks that polymerize and crystallize into layered structures, characterized by their atomically precise structure, permanent porosity and high modularity. Imine-linked COFs are one of the most important and promising classes of macromolecular sheets, which form by the condensation...