Human skin oils are significant scavengers of atmospheric oxidants in occupied indoor environments. Many techniques used to study gas-phase transformations of surface films indoors have been limited to off-line bulk analysis, although more surface-selective methodologies are emerging. Here, we present a multi-prong analytical approach to characterizing skin oil ozonolysis. Skin...
Metal-organic frameworks (MOFs) are porous, crystalline materials synthesized by combining metal nodes and organic linkers through self-assembly. The diverse range of building blocks available allows for extensive tunability of MOFs, enabling the optimization of these materials for various applications, such as gas storage, separations, and catalysis. This study aimed to...
Metal–Organic Frameworks (MOFs) is a class of material comprising organic linkers and inorganic, metal-ion-containing nodes, with diverse functionalities and wide-range of applications. Because of their porous nature and functional nodes and linkers, they are competent candidates for gas storage, separation, catalysis, and so on. Most MOFs, however, are intrinsically insulating,...
This thesis document is comprised of three research projects. The first investigates the active vibrational modes involved in twisted intramolecular charge transfer in a Julolidine-BODIPY dyad using two-dimensional electronic spectroscopy along with DFT calculations. We identified two types of vibrations, compression and torsional motion, as playing an important role in...
Renewable energy technology, more so than ever before, is critical to the survival of humanity. For decades, concentrated efforts into designing and developing such novel devices resulted in the innovation of solar-driven photovoltaics that were competitive with nonrenewable alternatives. This thesis explores the dynamic behavior of alternative material candidates that...
Many processes in nature and human-made settings rely on the unique properties of charged metal oxide:aqueous interfaces. Despite their ubiquity, these buried interfaces are challenging to study, since any analytical technique aiming to overcome the relatively small number density of interfacial versus bulk species must be highly sensitive and surface-selective....
This dissertation focuses on the study of the superionic state in multicomponent systems, where the smaller component exhibits delocalization and mobility while still maintaining system compactness through component attractions. Superionic behavior is widely observed in various systems and plays a crucial role in ceramic superionic conductors, which offer high ion...
One of the greatest challenges in heterogeneous catalysis is the rational design and development of new catalytic systems, due to synthetic limitations in the design of solid catalysts and inhomogeneity of chemical sites at solid surfaces. This obfuscates understanding of catalyst behavior and slows improvements of processes. One approach to...
Clean water supplies are required for industry and general life. However, water shortages dueto pollution and human activity are increasingly common, and new, more efficient, materials need
to be made to increase clean water supplies. To do this, fundamental information on the interaction
of water with ions at the atomic...
The continuing increase in atmospheric CO2 to concentrations exceeding 400 ppm has attracted considerable attention from both scientists and policymakers. Industrial fossil fuel consumption generates a significant amount of CO2 emissions, and in particular, energy-intensive molecular separations that require thermal processes, such as distillation, drying, or evaporation, are responsible for...
Despite the increasing interest in biogenic secondary organic aerosols (SOAs), their role in the climate system remains the greatest source of uncertainty in global models. Cloud formation, critical for the net cooling effect provided by cloud cover, is dependent on the abundance of SOA particles and their ability to activate...
Metalloenzymes catalyze remarkable reactions in Nature using transition metal ions. Common earth-abundant metals like copper, iron, zinc, and magnesium catalyze reactions that are the basis of life. These metal sites lend their chemistries to facilitate these reactions, making studying the structure and properties important in understanding the enzymes' abilities and...
Recent progress in semiconductor synthesis and photophysics has revealed a host of new materials with exciting properties for applications in optoelectronic devices such as sensors, photovoltaics, solid state lighting, and more. One of the most significant recent additions to the field is the class of hybrid and inorganic materials that...
Early transition metal organometallics chemisorbed on extremely Brønsted acidic sulfated metal oxides such as sulfated alumina (AlS) and sulfated zirconia (ZrS) produce highly active single-site catalysts for olefin polymerization, alkene and arene hydrogenation, and alkane hydrogenolysis, typically with a large percentage of catalytically significant sites. The low support conjugate basicity...
Heterogenous catalysis is the pillar of chemical production and a crucial aspect for optimization toward a sustainable future. To improve the current design of heterogeneous catalysts of maximal activity and product selectivity, gaining fundamental understanding of the catalytic active sites is crucial. The nature of active sites has been the...
Understanding the characteristics of interfaces between materials and solvent media such as structure, chemistry, and charge remains crucial to determining the properties and performance of numerous systems and technologies. This thesis focuses specifically on characterizing the interactions of water at oxide interfaces. A large collection of questions remains unanswered about...
Amyloid beta oligomers (AβOs) are a key instigator of neurodegeneration in Alzheimer’s disease (AD). The work presented in this thesis includes three disease-modifying approaches to disrupt pathological AβO-related mechanisms in AD: (1) inhibiting AβO buildup, (2) blocking AβO-induced tau phosphorylation, and (3) neutralizing AβOs. These three approaches were tested in...
Soft materials are inherently fluxional, with morphologies and behaviors that are dictated by their solvation state. Thus, many organic systems cannot be reliably imaged by static dry state or cryogenic-transmission electron microscopy (TEM). This motivated us to pursue liquid cell (LC) TEM method development to study our own materials and...
Uranium is a unique, multifaceted element that possesses rich chemistry and promise for challenging reactions. Pressing demands within nuclear stockpile stewardship and the nuclear energy sector call for development of this relatively understudied element. Uranium metal–organic frameworks (U-MOFs), a class of nanoscale hybrid materials, harness the exceptional attributes of uranium...
Single-use plastic waste pollution will cause significant harm to the environment if left unaddressed. One possible mitigation strategy is to develop processes, e.g. catalytic hydrogenolysis, that can convert (i.e. upcycle) waste plastics into value-added products capable of participating in a circular economy. Platinum (Pt) catalysts on strontium titanate nanocuboid supports...
Soft materials are inherently fluxional, with morphologies and behaviors that are dictated by their solvation state. Thus, many organic systems cannot be reliably imaged by static dry state or cryogenic-transmission electron microscopy (TEM). This motivated us to pursue liquid cell (LC) TEM method development to study our own materials and...
Uranium is a unique, multifaceted element that possesses rich chemistry and promise for challenging reactions. Pressing demands within nuclear stockpile stewardship and the nuclear energy sector call for development of this relatively understudied element. Uranium metal–organic frameworks (U-MOFs), a class of nanoscale hybrid materials, harness the exceptional attributes of uranium...
Amyloid beta oligomers (AβOs) are a key instigator of neurodegeneration in Alzheimer’s disease (AD). The work presented in this thesis includes three disease-modifying approaches to disrupt pathological AβO-related mechanisms in AD: (1) inhibiting AβO buildup, (2) blocking AβO-induced tau phosphorylation, and (3) neutralizing AβOs. These three approaches were tested in...
A fundamental materials science question is “why and how will this material form?” The experimental,computation, and time resources necessary to answer this question consume significant resources due to the
predominantly trial-and-error based approaches common in materials research. This dissertation reintroduces
a number of fundamental thermodynamics-based tools for the study of...
DNA is extremely versatile and powerful, both as a construct in biological applications and as a ligand in materials design due to the fact that its recognition properties can be programmed through sequence and length. Spherical nucleic acids (SNAs), nanoparticles surrounded by a dense shell of DNA or RNA, are...
Wireless power strategies are critical to system level implementation of bio-integrated devices. To achieve mechanically robust, manufacturable systems, batteries are often integrated as an on-board power source to support sensing, wireless communication and signal conditioning. Unfortunately, most sources of battery power use hazardous and environmentally harmful materials, which frustrate incorporation...
Understanding the photophysical processes of organic materials is important for utilizing them as functional photonic materials. Typical photophysical processes include intersystem crossing, charge transfer (CT), symmetry-breaking charge separation (SB-CS), singlet fission (SF), etc. There are serval factors that can lead to different photophysical processes, such as the molecular energy levels,...
Industrial processes heavily rely on catalysts to control product selectivity and lower energy barriers required for chemical transformations. Catalysts are most commonly solid heterogeneous catalysts that facilitate separations from reaction mixtures and enhance recyclability. Heterogeneous catalysts used in industrial processes exhibit efficacious results, but in certain instances drawing structure-function relationships...
This thesis presents results on photophysics and spin dynamics of photoactive organic molecules that possess one unpaired electron spin in the ground state and two or three unpaired spins upon photoexcitation. The excited state dynamics of the systems were studied using transient optical absorption spectroscopies and non-Boltzmann population on the...
Understanding the mechanisms associated with chemical catalysis is vital for not only the rational improvement of their capabilities, but also for the advancement of the fundamental knowledge affiliated with the systems in question. These new insights can help predict new reactivities towards more challenging substrates which will allow for easier...
Carbon nanomaterials, such as graphene and graphene oxide, have outstanding mechanical strength, stiffness, and toughness that surpass those of materials currently used to build structures. However, these properties are limited to the nanoscale and have not yet been attained in macroscopic composites containing carbon nanomaterials. To integrate the mechanical properties...
Proteins are the nanoscale building blocks of life. Their sophisticated but well-defined architectures result in complex biological functions, including ones involved in metabolism, photosynthesis, transcription, translation, and immunity. To study and improve upon the natural functions of proteins, it is desirable to develop methodology for organizing proteins into targeted architectures....
Per- and polyfluoroalkyl substances (PFAS) are man-made compounds containing multiple carbon–fluorine bonds. The unique properties of this strong bond simultaneously make PFAS useful for a number of industrial and consumer applications, toxic to living organisms, and difficult to remediate. Because the pervasive pollution of water sources with PFAS occurs at...
Organic photovoltaics offer an opportunity to make solar cells more affordable and widely accessible using cheap, solution-processable light-absorbing layers. In order to realize new technologies, a fundamental understanding of organic chromophore photophysics is required to overcome efficiency limitations. Throughout this doctoral work, I investigated the kinetic and physical characteristics of...
The construction of new C–C bonds remains a central facet of organic chemistry due to its critical role in the synthesis of pharmaceutical compounds and organic materials. Mild and selective methodologies are often required for efficient formation of these bonds in natural product total synthesis, medicinal chemistry campaigns, and more....
Triplet excited state chemistry has enabled a range of important organic transformations by accessing reaction pathways inaccessible to photoredox chemistry. Such photoreactions are triggered by triplet photosensitizers, which absorb visible-light photons and transfer the energy to the substrate or to a co-catalyst through triplet-triplet energy transfer (TT EnT). The most...
As the interest in rational synthesis for solid-state materials accelerates, there is an urgent need to understand the design principles concealed within these reactions. In situ material synthesis provides such an avenue to not only uncover these assembling rules, but also for finding new materials even in seemingly familiar phase...
Biomedical imaging is an essential part of medicine that enables the non-invasive observation of biological phenomena. This, in turn, allows for more accurate and earlier diagnoses, monitoring of therapies, and even fundamental research into biological processes. Molecular imaging, a fast-growing subdiscipline of biomedical imaging, seeks to image biochemical processes at...
Secondary organic aerosol (SOA) particles are a class of highly abundant atmospheric constituents that represent a substantial fraction of carbon within the climate system. A subset of naturally-occurring SOA particles are formed through atmospheric oxidation of biogenic volatile organic compounds (BVOCs), forming oxygenated products of lower volatility that can partition...
Biological therapeutics have revolutionized the way we treat cancer due to their ability to target tumors discriminately, leaving healthy cells unaffected. However, our inability to tailor the structure of biologics may hamper their optimization for efficacy. This lack of programmability contributes to factors such as immunogenic responses, inability to penetrate...
Dynamic covalent chemistry (DCC) combines the strength and directionality of covalent bonds with the reversibility of supramolecular interactions. The formation and stability of these bonds are typically regulated by parameters such as temperature, pH, concentration, catalyst loading and light. Light is an exceptionally powerful stimulus because it can be applied...
Crystalline and Framework materials make up a broad class of structures which are known for their precise and regular nature. Because these materials have predictable structures and compositions to their networks, they are widely used for several applications including electronics, optics, and catalysis. While these materials are of particular interest,...
Part I:Current approaches to synthesize π-conjugated polymers are dominated by thermally driven, transition-metal-mediated reactions. Herein we7 show that electron-deficient Grignard monomers readily polymerize under visible-light irradiation at room temperature in the absence of a catalyst. The product distribution can be tuned by the wavelength of irradiation based on the absorption...
Cobalt(III) Schiff-base complexes (Co(III)-sb) have been utilized in the literature as antibacterial, antiviral, and inhibitory agents. Recent work has utilized their ability to displace endogenous metals from metalloproteins that exhibit aberrant gain of function pathologies in human disease. Specifically, in this dissertation Co(III)-sb has been applied as inhibitors of pathogenic...
The study of solid-state organic chromophores has been soaring in the last decade owing to their wide applications in organic photovoltaics. These organic chromophores can absorb light in the visible region and form free charge carriers with proper design in molecular structure and device fabrication. In solid state, chromophores are...
Peptides consists of a series of amino acids connected via an amide type of covalent chemical bond. A diverse field of applications such as biosensors,2 catalysis,4 and biomedicine6 include the oligomeric forms of peptides due to their genuine features comparing to other biomacromolecules. Particularly, peptides in the field of biomedical...
Realizing electromagnetic metamaterials which operate in the optical regime requires creating precise arrangements of sub-100 nm building blocks. As such, fabricating these materials using conventional lithographic methods is extremely costly. On the other hand, bottom-up assembly of nanoparticles into crystalline superlattices offers opportunities to explore the scalable fabrication of 2-...
Semiconductor nanocrystals possess unique photophysical properties that make them desirable for many optoelectronic applications such as photovoltaics, LEDs, and quantum computing. When the size of a semiconductor is reduced to below the excitonic Bohr radius of the material, its carriers becomes quantum confined resulting in drastic changes to optical, electronic,...
The demand for low cost, unconventional electronics requires new materials with unique characteristics that the traditionally used silicon-based technologies cannot provide. Metal oxide semiconductors, such has amorphous indium gallium zinc oxide (a-IGZO), have made impressive strides as alternatives to amorphous silicon for electronics applications. However, to achieve the full potential...
Soft functional materials are fundamentally interesting from a chemistry standpoint and have exciting applications in robotics, chemical and biomolecule sensing, and biomedical engineering. In addition, soft materials are also useful in lithography, particularly cantilever-free scanning probe lithography (CFSPL). Because of their low modulus, biocompatibility, stimuli responsiveness, malleability, and other characteristics,...
Among the most valuable applications of organometallic chemistry is its implementation in the field of catalysis. Many industrial processes rely heavily on catalysis, employing organometallic complexes in the production of commodity chemicals, fine chemicals, materials, and even in the discovery and development of pharmaceuticals. Through decades of intense study, homogeneous...
In an era of personalized medicine, the clinical community has become increasingly focused on understanding diseases at the cellular and molecular level. Magnetic resonance imaging (MRI) is a powerful imaging modality for acquiring anatomical and functional information. However, it has limited applications in field of molecular imaging due to low...
Two-dimensional (2D) hybrid halide perovskites have been the response to their exciting but woefully unstable 3D counterparts. These 2D perovskites have been shown to have respectable stabilities as photovoltaic absorbers, yet they lag behind the 3D perovskites in terms of efficiency. With the need to catch up to the efficiencies...
The ubiquitous role of water in biochemical, electrochemical, and geochemical systems has driven scientific interest in studying the fundamental hydrogen-bonding interactions that water molecules exhibit in the presence of different materials.Specifically, we focus on the interactions characterizing water at the interface between two bulk media, as these are essential to...
This work examines important heterogeneous processes of organic molecules on surfaces, in the contexts of atmospheric and indoor environments. In large forest ecosystems, biogenic secondary organic aerosols (SOAs) constitute a dominant fraction of organic particulate matter in the atmosphere. The formation of SOAs starts from the emission of volatile organic...
The translation of proteins as effective intracellular drug candidates is limited by the challenge of cellular entry and their vulnerability to degradation. To advance their therapeutic potential, cell-impermeable proteins can be readily transformed into protein spherical nucleic acids (ProSNAs) or encapsulated into liposomal spherical nucleic acids (L-SNAs), structures defined by...
The use of light to understand detailed electronic structure and chemical properties of a molecule through light-matter interaction is fundamentally essential to design and analyze any chemical system. Over the past decades, rapid developments on optics and laser techniques improved the detection efficiency of multiphoton processes with more detailed chemical...
Proteins are known to have diverse biomedical functions and excellent catalytic performance; however, they are also fragile outside living cells, challenging their use in industrial applications. Metal-organic frameworks (MOFs) are highly porous crystalline materials that consist of metal cluster nodes and organic linkers. With their rigid structures, MOFs can effectively...
Noble metal nanoparticles (NPs) have shown promise as imaging agents, drug delivery platforms, and plasmonic sensors. Anisotropic gold NPs, such as gold nanostars, have particularly received attention due to their shape-dependent optical and spectral properties. With their 3D anisotropic structure with branches protruding into different directions and high surface areas,...
Recent progress in the field of nanomaterials has enabled significant advances in optoelectronic devices such as solar cells, light-emitting diodes, photocatalysts, and sensors. Nanoparticles feature superior optical and electronic properties that arise from quantum confinement and therefore cannot be attained used bulk materials. However, further developments in the field of...
Metallic conductivity and broken inversion symmetry were long thought to be contraindicated properties, under the assumption that long-range Coulombic interactions (screened by free charge carriers) were necessary for coordinated polar displacements. Within the past decade, the discovery of polar metals has prompted a rethinking of the relationship between metallicity and...
This thesis describes the synthesis and photophysical characterization of low-dimensionalmaterials—including thin-film semiconductors, colloidal quantum dots, and molecules—with the
broader motivation of integrating them into mixed-dimensional heterostructures with novel
responses to external stimuli. Due to their high surface area to volume ratio and incomplete
dielectric screening, mixed-dimensional heterostructures have high sensitivity...
Nanoparticles (NPs) are emerging as attractive drug carriers in therapeutic and diagnostic applications. The physiochemical properties of NPs, such as particle size, shape, and surface chemistry, play important roles in the functions of engineered nanoconstructs−NP cores with surface ligands. Recent work has screened these properties by monitoring cellular uptake and/or...
The building blocks of life are proteins. These incredible nanostructures are responsible for forming the diverse infrastructure of living systems and for performing countless biological functions. In Nature, these materials and systems achieve structural complexity and function through highly regulated and controlled assembly of protein building blocks, driven by specific...
Oligonucleotides can be used to modulate the regulation of pathological genes that are associated with various diseases. However, due to biological barriers, efficient delivery of oligonucleotides, especially to extrahepatic tissues, remains a challenge. To overcome these barriers, multiple delivery strategies have been developed, ranging from medicinal chemistry to nanotechnology. Nanoparticle-based...
Nanoparticle synthesis is capable of producing particles with any combination of structure, chemistry, size, shape, and surface. All of the different combinations of these physical properties can produce nanoparticles with almost countless materials properties suited for many applications. Given this interest in using nanoparticles in so many different fields, including...
One of the central challenges in solid-state chemistry is synthetic control over structure. Owing to limited reactivity of Pb with transition metals at ambient pressure and high temperature as well as the variety of properties that emerge from the few known binary transition-metal–Pb compounds, this research focuses on accessing and...
High-throughput methods enable rapid experimentation and/or screening of thousands of samples simultaneously. Mass-spectrometry based methods are of particular interest since they provide a label-free way to detect all species present in a given reaction mixture. To circumvent sample preparation and purification—which is typically a slow process—the Mrksich group developed a...
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...
Gold nanoparticles (AuNPs) display unique characteristics compared to their macro-counterparts that are dependent on shape, size, and attached surface molecules. Methods have been developed to precisely control both size and shape of AuNPs for specific applications. The biocompatibility, plasmonic properties, and ease of functionalization with thiolated molecules, make gold nanoparticles...
Functional electronic materials have transformed modern society toward a highly digitized and interconnected global community. The ever-growing demand for electronic devices with superior functionality poses a great challenge to the state-of-the-art field-effect transistors owing to the limited charge density afforded by silicon. Materials scientists and chemists have been working closely...
Commercial agriculture and industrial manufacturing have contaminated freshwater sources with persistent organic pollutants, heavy metals, and radioactive species. Effective mitigation of this pollution is paramount to safeguarding human health, animal and aquatic life, and the environment. Conventional adsorbents such as activated carbon, metal oxides, resins, and polymers attain moderate to...
Self-assembled monolayers for matrix-assisted laser desorption/ionization mass spectrometry (SAMDI-MS) is a platform that combines self-assembled monolayers of alkanethiolates on gold and MALDI mass spectrometry analysis to report mass changes resulting from surface reactions. The synthetic flexibility of the monolayer and the use of mass spectrometry as a generalizable readout method...
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...
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...