Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Quantum Chemical Pka Estimation Of Carbon Acids, Saturated Alcohols, And Ketones Via Quantitative Structure-Activity Relationships, Corey Adam Baldasare
Quantum Chemical Pka Estimation Of Carbon Acids, Saturated Alcohols, And Ketones Via Quantitative Structure-Activity Relationships, Corey Adam Baldasare
Browse all Theses and Dissertations
Acid dissociation constants, often expressed as pKa values, afford vital information with regards to molecular behavior in various environments and are of significance in fields of organic, inorganic, and medicinal chemistry. Several quantitative structure-activity relationships (QSARs) were developed that correlate experimental pKas for a given class of compounds with a descriptor(s) calculated using density functional theory at the B3LYP/6-31+G** level utilizing the CPCM solvent model. A set of carbon acids provided a good final QSAR model of experimental aqueous pKas versus ΔEH2O (R2 = 0.9647) upon removal of three aldehydes as outliers. A study of saturated alcohols offered a final …
Theoretical Estimation Of PkA'S Of Pyrimidines And Related Heterocycles, Rachael Ann Wessner
Theoretical Estimation Of PkA'S Of Pyrimidines And Related Heterocycles, Rachael Ann Wessner
Browse all Theses and Dissertations
Pyrimidines and related heterocycles are an important class of compounds with a wide variety of applications. As a result, there is great interest in the chemical properties of these compounds, specifically their pKa's. Despite the importance of these compounds their reported pKa's are often only approximations or are completely absent from literature. Experimentally measuring pKa's can be challenging, especially if the pKa is below zero. Alternatively, pKa's can be estimated computationally using a Quantitative Structure-Activity Relationship (QSAR). However, most of the compounds included in this study exist as two or more forms that arise from tautomerism. Tautomerism complicates the estimation …
Quantum Chemical Investigations Of Nucleophilic Aromatic Substitution Reactions And Acid Dissociations Of Aliphatic Carboxylic Acids, David Henry Schory
Quantum Chemical Investigations Of Nucleophilic Aromatic Substitution Reactions And Acid Dissociations Of Aliphatic Carboxylic Acids, David Henry Schory
Browse all Theses and Dissertations
Quantum chemical analysis was used to examine nucleophilic aromatic substitution reactions of fluorinated benzophenones, diphenyl sulfones, and triphenylphosphine oxides. Some experimental results for these compounds were contrary to conventional wisdom, which holds that calculated atomic charges for the aromatic sites and 13C-NMR and 19F-NMR chemical shifts should allow prediction of the preferred sites for aromatic substitution. Density functional theory (B3LYP/6-31+G*//RM1) and semi-empirical (RM1) quantum chemical calculations were employed to study the intermediates in the reaction pathways in order to identify the preferred paths for aromatic substitution. In most cases studied para substitution pathways had the lower energy intermediates …