Photocontrol of ion permeation in lipid vesicles with (bola)amphiphilic spirooxazines.

Three (bola)amphiphilic spirooxazines have been synthesized and their photochromism has been characterized. The large biphotochromic structure of 2 significantly affects its conformational flexibility and the rate constants for thermal ring closure are particularly dependent on the lipid phase state. Two comprehensive ion permeation studies were performed to examine the effect of spirooxazine inclusion and isomerization on membrane permeability.

Challenges in predicting ΔrxnG in solution: the mechanism of ether-catalyzed hydroboration of alkenes.

Ab initio (coupled-cluster and density-functional) calculations of Gibbs reaction energies in solution, with new entropy-of-solvation damping terms, were performed for the ether-catalyzed hydroboration of alkenes. The goal was to test the accuracy of continuum-solvation models for reactions of neutral species in nonaqueous solvents, and the hope was to achieve an accuracy sufficient to address the mechanism in the "Pasto case": B2H6 + alkene in THF solvent. Brown's SN2/SN1 "dissociative" mechanism, of SN2 formation of borane-ether adducts followed by SN1 alkene attack, was at odds with Pasto's original SN2/SN2 hypothesis, and while Brown could prove his mechanism for a variety of cases, he could not perform the experimental test with THF adducts in THF solvent, where the higher THF concentrations might favor an SN2 second step.

Assessing the decontamination efficiency of a three-component flocculating system in the treatment of oilfield-produced water.

Produced water is a complex mixture of oil, water, dissolved solids, and suspended solids. It represents the largest volume of waste associated with the oil and gas industry, and its management is a costly aspect of oil recovery. Therefore, the development of effective treatment technologies for produced water is essential from both ecological and economic standpoints.