| dc.description.abstract | The world is 8 years away from reaching the 2030 U.N. deadline requiring the reduction of carbon equivalent emissions by half before reaching a 1.5◦C temperature rise that tips the scale of climate change against us. Within the next decade, the world needs to achieve its 17 sustainable development goals to meet the need of the present generation without compromising the ability of future ones to meet their own needs. In the last 37 years since sustainable development was defined, the world has made tremendous progress in shifting away from non-renewable to renewable resources. However, to meet sustainable development goals, the world must come together and bring forth alternatives that foster economic, environmental, and societal pillars. Scientific research, from both the private and public sectors, is crucial to advancing industrial innovation while protecting terrestrial and aquatic life. From a socioeconomic perspective, every 1% increase in research and development (R&D) spending leads to roughly 120,000 new jobs and approximately $3 billion in earnings.174 If the world comes together, as it did to repair the ozone layer, to solve the existential threat that is posed by climate change, then, in the remaining 8 years the U.N. sustainable goals will be satisfied. This dissertation brings forth scientific research centered around the deployment of earth-abundant components (both catalyst and substrates), advancing greener chemistries, and the development of smart manufacturing platforms to leverage sustainable change in the pharmaceutical, plastics, and detergent industries. Through an in-depth kinetic and mechanistic study of an iron homogeneous pincer complex, we advance the general understanding needed for its industrial adoption. This complex enables a route for the reduction of 45% of substrates commonly reduced in pharmaceutical processes. Dehydrogenations of limited substrates can also be conducted with this complex. In this investigation, we describe the first-order dependence of the reaction rate with respect to hydrogen and catalyst, an activation energy of 93.6 ± 9.7 kJ mol−1, and a pre-exponential factor of 1.75 × 1015 M−1s−1. Additionally, transition state energetic insights through Eyring plot theory, describe the Gibbs free energy of 79.5 ± 26.8 KJ mol−1, an enthalpy of 90.8 ± 9.6 KJ mol−1, and an entropy of 37 ± 28 J mol−1 K−1. This key evidence supports the findings that the rate-determining step is associatedwith hydrogen addition and is assisted by a proton shuttle hydrogen bonding network in the catalyst cycle. Also, through in-situ pressure nuclear magnetic resonance (NMR) investigation, we made an unprecedented discovery that has vast implications for the understanding of nitrile hydrogenation mechanisms. We found crucial evidence of two oligomeric intermediate cascades governed by imine self-condensation and benzylamine condensation, respectively. The higher oligomeric intermediates also hold pharmaceutical value, as they are important substrates used in substituted imidazoles in important drug substances and agrochemicals. Based on the kinetic and mechanistic findings, we design, construct, and pursue the first iteration of a continuous, modular hydrogenation station. Continuous flow reactors are critical to unlocking consistent quality by control (QbC) strategies that reliably make drug products in accordance with FDA regulations. To enable this manufacturing modality, a custom setup was designed and built from the ground up; including enhanced safety elements for the safe use of hydrogen gas, a highly explosive substance. Industrial innovation is key to unlocking efficient operations that lead to more responsible resource utilization. Additionally, we expand the tools behind residence time distributions in the characterization of continuous reactions by implementing an off-line low-field NMR technique that is far superior to commonly used on-line UV-Vis analytics. Included here are new tracer options, previously unavailable for this type of analysis that better resemble substrates used in chemical reactions. To further the development of smart manufacturing, we deploy conductivity to measure the kinetics in a batch reactor for the nucleophilic substitution between benzylamine (the product of interest in kinetic/mechanistic and continuous reaction platform) and benzyl bromide. Conductivity is an inexpensive, reliable way to measure the concentrations of electrolytes in solution; anecessary and common operation required by pharmaceutical processes. To develop it as a process analytical technique (PAT), we construct a LabVIEW code for data acquisition. To enable this methodology for smart manufacturing, we couple data acquisition with kinetic simulations that can be utilized for predictive control. Focused on employing greener chemistry for the production of plastics, we adopt a bioengineered polysaccharide, i.e.,α-1,3-glucan, that is naturally present in the plaque produced by mouth microorganisms and plant’s cell wall. To add thermoplastic properties to naturally occurring polymers, we perform an esterification with palmitoyl chloride, a moiety of plamitic acid. Through reaction engineering improvements we increase yield, selectivity, recovery, and decrease process mass intensity (PMI) beyond what is known in the literature. Here, we also conduct application testing into the chemical, mechanical, and transport properties of biodegradable polysaccharide thermoplastics for their use in the food packaging industry. To eliminate the permanence of detergents in nature, we attempt to make a greener non-ionic detergent with the α-1,3-glucan polysaccharide and benzoyl chloride, a moiety of benzoic acid, in a completely aqueous system. The α-1,3-glucan-benzoate (GB) materials are characterized through 1H and DOSY NMR spectroscopy, FTIR, and solubility. We employ sodium hydroxideto activate the polysaccharide and promote solubility in the reaction media. Cation species have a strong influence on activation which follows trends from the Hofmeister series. Throughout this investigation, we inspect conditions to maximize selectivity, yield, and solubility, while minimizing process mass intensity. Finally, we go a step beyond in the characterization of α-1,3-glucan (microcrystalline and wet cake) with low field NMR and gas adsorption to investigate the specific surface area of "soft-matter" polysaccharides under conditions of use. Gas adsorption, a well-established technique to measure specific surface area, pore volume and diameter of porous media, undergoes a dehydrating pretreatment step that causes soft-matter to shrivel and morphologically change its structure. To measure the true nature of the material under application relevant conditions, we look at low-field NMR; an analytical technique that uses solvents (wet conditions) to measure morphological properties of materials. Additionally, we explore the physics of x-ray illuminated tomography and its applications in catalysis, geological samples, and electrochemistry under conditions of use. | |
