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...
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...
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...
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,...
This introductory chemistry textbook was compiled by Shelby Hatch at Northwestern University and is adapted from the following sources:
"Introductory Chemistry" by David W. Ball, The Saylor Foundation, Cleveland State University, is licensed
under CC BY-NC-SA 4.0 and is available at https://open.umn.edu/opentextbooks/textbooks/introductory-chemistry ; "Chemistry of Cooking" by Sorangel Rodriguez-Velazquez, American...
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...
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....
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...