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Ground and Excited States of Zinc Phthalocyanine, Zinc Tetrabenzoporphyrin, and Azaporphyrin Analogs Using DFT and TDDFT With Franck-Condon Analysis

Description

The electronic structure of eight zinc-centered porphyrin macrocyclic molecules are investigated using density functional theory for ground-state properties, time-dependent density functional theory (TDDFT) for excited states, and Franck-Condon (FC) analysis for further characterization of the UV-vis spectrum. Symmetry breaking was utilized to find the lowest energy of the excited states…

The electronic structure of eight zinc-centered porphyrin macrocyclic molecules are investigated using density functional theory for ground-state properties, time-dependent density functional theory (TDDFT) for excited states, and Franck-Condon (FC) analysis for further characterization of the UV-vis spectrum. Symmetry breaking was utilized to find the lowest energy of the excited states for many states in the spectra. To confirm the theoretical modeling, the spectroscopic result from zinc phthalocyanine (ZnPc) is used to compare to the TDDFT and FC result. After confirmation of the modeling, five more planar molecules are investigated: zinc tetrabenzoporphyrin (ZnTBP), zinc tetrabenzomonoazaporphyrin (ZnTBMAP), zinc tetrabenzocisdiazaporphyrin (ZnTBcisDAP), zinc tetrabenzotransdiazaporphyrin (ZnTBtransDAP), and zinc tetrabenzotriazaporphyrin (ZnTBTrAP). The two latter molecules are then compared to their phenylated sister molecules: zinc monophenyltetrabenzotriazaporphyrin (ZnMPTBTrAP) and zinc diphenyltetrabenzotransdiazaporphyrin (ZnDPTBtransDAP). The spectroscopic results from the synthesis of ZnMPTBTrAP and ZnDPTBtransDAP are then compared to their theoretical models and non-phenylated pairs. While the Franck-Condon results were not as illuminating for every B-band, the Q-band results were successful in all eight molecules, with a considerable amount of spectral analysis in the range of interest between 300 and 750 nm. The π-π* transitions are evident in the results for all of the Q bands, while satellite vibrations are also visible in the spectra. In particular, this investigation finds that, while ZnPc has a D4h symmetry at ground state, a C4v symmetry is predicted in the excited-state Q band region. The theoretical results for ZnPc found an excitation energy at the Q-band 0-0 transition of 1.88 eV in vacuum, which is in remarkable agreement with published gas-phase spectroscopy, as well as our own results of ZnPc in solution with Tetrahydrofuran that are provided in this paper.
ContributorsTheisen, Rebekah (Author) / Huang, Liang (Author) / Fleetham, Tyler (Author) / Adams, James (Author) / Li, Jian (Author) / Ira A. Fulton Schools of Engineering (Contributor)
Created2015-03-07

The Relationship Between Grip Strength and Physical Activity in Preschoolers Aged 3-5 Years Old at Early Care Education Sites in Low-Income Communities

Description
As obesity rates continue to rise in adolescents and young children, the concern for poor future health of the younger population grows. Physical activity and improving nutrition are two ways to combat obesity rates, and the Sustainability via Active Gardening Education (SAGE) project addresses this in underserved and low-income communities…

As obesity rates continue to rise in adolescents and young children, the concern for poor future health of the younger population grows. Physical activity and improving nutrition are two ways to combat obesity rates, and the Sustainability via Active Gardening Education (SAGE) project addresses this in underserved and low-income communities in Maricopa County. This project employs a curriculum designed to promote physical activity and healthy eating for Early Care and Education (ECE) sites, most of which are daycares. Further, utilizing indicators of future health can also allow for us to understand and lower obesity rates. One indicator of future health is grip strength: greater grip strength is associated with healthier outcomes such as lower triglycerides, blood pressure, and body mass index. Grip strength has been observed in the older population; however, there are few studies looking at grip strength in younger children, namely preschoolers. As grip strength is a predictor of health, it follows that it should be observed in preschoolers, and improved, if possible, by factors such as physical activity, which would ultimately improve obesity rates. This study aimed to see if there was any relationship between physical activity and grip strength in preschoolers aged 3-5 years old. To do so, grip strength, hand length, height, weight, and information regarding physical activity of preschoolers enrolled in the SAGE project were collected. Physical activity and grip strength were not found to be significantly associated in this study; however, hand length and hand strength were associated. Among secondary outcomes, it was observed that males of ages 3 to 5-years-old may have greater hand grip strength than females of the same age group. Although this was not statistically significant, there was a trend toward statistical significance. Small sample size hampered observation of expected relationships between hand grip strength and dominant hand of the participants, and hand grip strength was not significantly related with BMI. Future directions would consist of collecting longitudinal data, as well as calling back previous years’ participants for additional data, so that there is a larger sample size for data analysis.
ContributorsAtluri, Haarika (Author) / Lee, Rebecca (Thesis director) / Tucker, Derek (Committee member) / Cantu Garcia, Lisbeth (Committee member) / De Mello, Gabrielli (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2024-05