Alcohols play important roles in many chemical and biological processes, and their acid/base behaviors are often important for these roles. In this study we ask the question, “Can the electronic properties of these compounds offer clues to the compounds' acid/base behaviors?” The study considers whether selected quantum chemical properties can be used to find correlations with the experimental pKa's of the alcohols (aliphatic and aromatic). Calculations were carried out for these alcohols using the semi-empirical RM1 method and the more advanced density functional theory (DFT) B3LYP/6-31+G* method. Significant correlations were found for several quantum chemical descriptors. It was also found that conformer selection plays an important role in obtaining the lowest energy form of each alcohol for analysis.
Almost 200 years ago John Dalton proposed that the composition of the gases in the Earth's atmosphere should change with altitude, the heavier gases being relatively more abundant at lower elevations and the lighter ones relatively more abundant at higher altitudes. In 2006 this proposal was experimentally confirmed at low altitudes (0-4 meters) by careful measurements of the ratio of argon to nitrogen [Y. Adachi et al., Science 2006, 311, 142] at a desert location. In the present work a dynamic, isothermal cellular automata model for the distributions of nitrogen, oxygen, argon, and carbon dioxide in the atmosphere is presented and compared with the predictions of the barometric equation. The cellular automata model employs two rules: a gravitational rule based on the masses of the molecular constituents and a motional rule based on their relative average speeds. The model captures the basic features of the gas distribution with altitude as well as the expected relative uncertainties caused by the diffusive motions of the gas molecules.